SMSC FDC37C93

FDC37C93xAPM
ADVANCE INFORMATION
Plug and Play Compatible Ultra I/O™ Controller
with Soft Power Management
FEATURES
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5 Volt Operation
ISA Plug-and-Play Standard (Version 1.0a)
Compatible Register Set
Soft Power Management, SMI Support
ACPI/Legacy Support
- SCI/SMI Support
- Power Management Timer
- Power Button Override Event
- Either Edge Triggered Interrupts
ACCESS.bus Support
8042 Keyboard Controller
- 2K Program ROM
- 256 Bytes Data RAM
- Asynchronous Access to Two Data
Registers and One Status Register
- Supports Interrupt and Polling Access
- 8 Bit Timer/Counter
- Port 92 Support
- Fast Gate A20 and Hardware Keyboard
Reset
Real Time Clock
- MC146818 and DS1287 Compatible
- 256 Bytes of Battery Backed CMOS in
Two Banks of 128 Bytes
- 128 Bytes of CMOS RAM Lockable in
4x32 Byte Blocks
- 12 and 24 Hour Time Format
- Binary and BCD Format
- 1 µA Standby Current (typ)
Intelligent Auto Power Management
2.88MB Super I/O Floppy Disk Controller
- Relocatable to 480 Different Addresses
- 13 IRQ Options
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Four DMA Options
Licensed CMOS 765B Floppy Disk
Controller
- Advanced Digital Data Separator
- Software and Register Compatible with
SMSC's Proprietary 82077AA
Compatible Core
- Sophisticated Power Control Circuitry
(PCC) Including Multiple Powerdown
Modes for Reduced Power Consumption
- Game Port Select Logic
- Supports Two Floppy Drives Directly
- 24mA AT Bus Drivers
- Low Power CMOS Design
Licensed CMOS 765B Floppy Disk
Controller Core
- Supports Vertical Recording Format
- 16 Byte Data FIFO
- 100% IBM® Compatibility
- Detects All Overrun and Underrun
Conditions
- 48mA Drivers and Schmitt Trigger Inputs
- DMA Enable Logic
- Data Rate and Drive Control Registers
Enhanced Digital Data Separator
- Low Cost Implementation
- No Filter Components Required
- 2 Mbps, 1 Mbps, 500 Kbps, 300 Kbps,
250 Kbps Data Rates
- Programmable Precompensation Modes
Serial Ports
- Relocatable to 480 Different Addresses
TABLE OF CONTENTS
FEATURES ........................................................................................................................................1
GENERAL DESCRIPTION..................................................................................................................4
PIN CONFIGURATION.......................................................................................................................5
DESCRIPTION OF PIN FUNCTIONS...........................................................................................6
FUNCTIONAL DESCRIPTION ..........................................................................................................15
SUPER I/O REGISTERS ...........................................................................................................15
HOST PROCESSOR INTERFACE.............................................................................................15
FLOPPY DISK CONTROLLER...................................................................................................16
FDC INTERNAL REGISTERS....................................................................................................16
INSTRUCTION SET .........................................................................................................................44
SERIAL PORT (UART) .....................................................................................................................70
INFRARED INTERFACE...................................................................................................................85
PARALLEL PORT.............................................................................................................................86
IBM XT/AT COMPATIBLE, BI-DIRECTIONAL AND EPP MODES..............................................88
EXTENDED CAPABILITIES PARALLEL PORT ..........................................................................95
AUTO POWER MANAGEMENT .....................................................................................................111
INTEGRATED DRIVE ELECTRONICS INTERFACE .......................................................................116
HOST FILE REGISTERS .........................................................................................................116
TASK FILE REGISTERS..........................................................................................................116
IDE OUTPUT ENABLES ..........................................................................................................117
BIOS BUFFER.........................................................................................................................118
GENERAL PURPOSE I/O FUNCTIONAL DESCRIPTION ...............................................................121
EITHER EDGE TRIGGERED INTERRUPTS ............................................................................135
8042 KEYBOARD CONTROLLER AND REAL TIME CLOCK FUNCTIONAL DESCRIPTION ...........136
SOFT POWER MANAGEMENT......................................................................................................161
SYSTEM MANAGEMENT INTERRUPT (SMI) .................................................................................165
ACCESS.BUS ................................................................................................................................166
ACPI FEATURES ...........................................................................................................................172
CONFIGURATION...................................................................................................................188
OPERATIONAL DESCRIPTION......................................................................................................238
POWER SUPPLY OPERATIONAL MODES .............................................................................242
TIMING DIAGRAMS ................................................................................................................243
ECP PARALLEL PORT TIMING......................................................................................................270
80 Arkay Drive
Hauppauge, NY. 11788
(516) 435-6000
FAX (516) 273-3123
2
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13 IRQ Options
Two High Speed NS16C550 Compatible
UARTs with Send/Receive 16 Byte
FIFOs
- Programmable Baud Rate Generator
- Modem Control Circuitry Including 230K
and 460K Baud
- IrDA, HP-SIR, ASK-IR Support
IDE Interface
- Relocatable to 480 Different Addresses
- 13 IRQ Options (IRQ Steering through
Chip)
- Two Channel/Four Drive Support
- On-Chip Decode and Select Logic
Compatible with IBM PC/XT® and
PC/AT® Embedded Hard Disk Drives
Serial EEPROM Interface
Multi-Mode Parallel Port with ChiProtect
- Relocatable to 480 Different Addresses
- 13 IRQ Options
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Four DMA Options
Standard Mode
- IBM PC/XT, PC/AT, and PS/2
Compatible Bidirectional ParallelPort
- Enhanced Mode
- Enhanced Parallel Port (EPP)
Compatible - EPP 1.7 and EPP 1.9
(IEEE 1284 Compliant)
- High Speed Mode
- Microsoft and Hewlett Packard
Extended Capabilities Port (ECP)
Compatible (IEEE 1284 Compliant)
- Incorporates ChiProtect Circuitry for
Protection Against Damage Due to
Printer Power-On
- 12 mA Output Drivers
ISA Host Interface
16 Bit Address Qualification
160 Pin QFP Package
*Note:
The “X” in the Ultra I/O part number is a designator that changes
depending upon the particular BIOS used inside the specific chip.
“2” denotes AMI Keyboard BIOS/”5” denotes Phoenix Keyboard
BIOS.
3
GENERAL DESCRIPTION
The FDC37C93xAPM incorporates a keyboard
interface, real-time clock, SMSC's true CMOS
765B floppy disk controller, advanced digital
data separator, 16 byte data FIFO, two 16C550
compatible UARTs, one Multi-Mode parallel port
which includes ChiProtect circuitry plus EPP
and ECP support, IDE interface, on-chip 24 mA
AT bus drivers, game port chip select and two
floppy direct drive support, as well as
ACCESS.bus, soft power management and SMI
support. The true CMOS 765B core provides
100% compatibility with IBM PC/XT and PC/AT
architectures in addition to providing data
overflow and underflow protection. The SMSC
advanced digital data separator incorporates
SMSC's patented data separator technology,
allowing for ease of testing and use. Both onchip UARTs are compatible with the NS16C550.
The parallel port, the IDE interface, and the
game port select logic are compatible with IBM
PC/AT architecture, as well as EPP and ECP.
The FDC37C93xAPM incorporates sophisticated
power control circuitry (PCC).
The PCC
supports multiple low power down modes.
These features include support of both legacy
and ACPI power management models through
the selection of SMI or SCI. It implements a 24bit power management timer, power button
override event (4 second button hold to turn off
the system) and either edge triggered interrupts.
The FDC37C93xAPM provides features for
compliance with the “Advanced Configuration
and Power Interface Specification” (ACPI).
IBM, PC/XT and PC/AT are registered trademarks and PS/2 is a trademark
of International Business Machines Corporation
SMSC is a registered trademark and Ultra I/O, ChiProtect, and Multi-Mode
are trademarks of Standard Microsystems Corporation
The FDC37C93xAPM provides support for the
ISA Plug-and-Play Standard (Version 1.0a) and
provides for the recommended functionality to
support Windows '95.
Through internal
configuration
registers,
each
of
the
FDC37C93xAPM's logical device's I/O address,
DMA channel and IRQ channel may be
programmed.
There are 480 I/O address
location options, 13 IRQ options, and three DMA
channel options for each logical device.
The FDC37C93xAPM does not require any
external filter components and is, therefore,
easy to use and offers lower system cost and
reduced board area. The FDC37C93xAPM is
software and register compatible with SMSC's
proprietary 82077AA core.
4
FDC37C93xAPM
160 Pin QFP
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
5
RESET_DRV
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
SA0
SA1
SA2
SA3
SA4
SA5
SA6
SA7
SA8
SA9
SA10
SA11
nCS/SA12
IRQ15
IRQ14
IRQ12
IRQ11
IRQ10
IRQ9
VCC
IRQ8/nIRQ8
IRQ7
IRQ6
IRQ5
IRQ4
IRQ3
IRQ1
nIOR
nIOW
AEN
GND
SD0
SD1
SD2
SD3
SD4
SD5
SD6
SD7
GND
DRVDEN0
DRVDEN1
nMTR0
nDS1
nDS0
nMTR1
GND
nDIR
nSTEP
nWDATA
nWGATE
nHDSEL
nINDEX
nTRK0
nWRTPRT
nRDATA
nDSKCHG
MEDIA_ID1
mEDIA_ID0
VCC
CLOCKI
nIDE1_OE
nHDCS0
nHDCS1
IDE1_IRQ
nHDCS2/SA13
nHDCS3/SA14
IDE2_IRQ/SA15
nIOROP
nIOWOP
VTR
nPOWER ON
BUTTON_IN
HCLK
16CLK
CLK01
CLK02
CLK03
GND
160
159
158
157
156
155
154
153
152
151
150
149
148
147
146
145
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
nDTR2
nCTS2
nRTS2
nDSR2
TXD2
RXD2
nDCD2
nRI2
nDCD1
nRI1
nDTR1
nCTS1
nRTS1
nDSR1
TXD1
RXD1
nSTB
nALF
nERROR
nINIT
nSLCTIN
VCC
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
GND
nACK
BUSY
PE
SLCT
VCC
XTAL2
GND
XTAL1
VBAT
PIN CONFIGURATION
nROMDIR
nROMCS
RD7
RD6
RD5
RD4
RD3
RD2
RD1
RD0
GP25
GP24
GP23
GP22
GP21
GP20
GP17
GP16
GP15
VCC
GP14
GP13
GP12
GP11
GP10
GND
MCLK
MDAT
KCLK
KDAT
IOCHRDY
TC
DRQ3
nDACK3
DRQ2
nDACK2
DRQ1
nDACK1
DRQ0
nDACK0
DESCRIPTION OF PIN FUNCTIONS
PIN NO.
NAME
SYMBOL
BUFFER
TYPE
PROCESSOR/HOST INTERFACE
72:79
System Data Bus
SD[0:7]
I/O24
41:52
System Address Bus
SA[0:11]
I
53
Chip Select/SA12 (Active Low)(Note 1, 4)
nCS
I
70
Address Enable (DMA master has bus control)
AEN
I
90
I/O Channel Ready
IOCHRDY
80
Reset Drive
RESET_DRV
67:61,
59:54
Interrupt Requests [1,3:12,14,15]
(Polarity control for IRQ8)
IRQ[1,3:12,
14,15]
82,84,
86,88
DMA Requests
DRQ[0:3]
81,83,
85,87
DMA Acknowledge
nDACK[0:3]
I
89
Terminal Count
TC
I
68
I/O Read
nIOR
I
69
I/O Write
nIOW
I
35
High Speed Clock Out 24/48 MHz
HCLK
O20
36
16 MHz Out
16CLK
O8SR
22
14.318 MHz Clock Input
CLOCKI
ICLK
37
14.318 MHz Clock Output 1
CLKO1
O16SR
38
14.318 MHz Clock Output 2
CLKO2
O8SR
39
14.318 MHz Clock Output 3
CLKO3
O8SR
OD24
IS
024/OD24
(Note 0)
O24
POWER PINS
21, 60,
101, 125,
139
+5V Supply Voltage
VCC
32
Trickle Voltage Input
VTR
Ground
GND
1, 8, 40,
71, 95,
123, 130
FDD INTERFACE
17
Read Disk Data
nRDATA
6
IS
DESCRIPTION OF PIN FUNCTIONS
PIN NO.
NAME
SYMBOL
BUFFER
TYPE
12
Write Gate
nWGATE
OD48
11
Write Disk Data
nWDATA
OD48
13
Head Select (1 = side 0)
nHDSEL
OD48
9
Step Direction (1 = out)
nDIR
OD48
10
Step Pulse
nSTEP
OD48
18
Disk Change
nDSKCHG
5,6
Drive Select Lines
nDS[1:0]
OD48
7,4
Motor On Lines
nMTR[1:0]
OD48
16
Write Protected
nWPROT
IS
15
Track 0
nTR0
IS
14
Index Pulse Input
nINDEX
IS
3,2
Drive Density Select [1:0]
DRVDEN
[1:0]
OD48
Media ID inputs. In floppy enhanced mode 2 these
inputs are the media ID [1:0] inputs. (Note 4)
MID[1:0]
IS
19,20
IS
SERIAL PORT 1 INTERFACE
145
Receive Serial Data 1
RXD1
I
146
Transmit Serial Data 1
TXD1
O4
148
Request to Send 1
nRTS1
O4
149
Clear to Send 1
nCTS1
I
150
Data Terminal Ready 1
nDTR1
O4
147
Data Set Ready 1
nDSR1
I
152
Data Carrier Detect 1
nDCD1
I
151
Ring Indicator 1
nRI1
I
155
Receive Serial Data 2 (Note 4)
RXD2
I
156
Transmit Serial Data 2 (Note 4)
TXD2
O4
158
Request to Send 2 (Note 4)
nRTS2
O4
159
Clear to Send 2 (Note 4)
nCTS2
I
160
Data Terminal Ready 2 (Note 4)
nDTR2
O4
157
Data Set Ready 2 (Note 4)
nDSR2
I
SERIAL PORT 2 INTERFACE
7
DESCRIPTION OF PIN FUNCTIONS
PIN NO.
NAME
SYMBOL
BUFFER
TYPE
154
Data Carrier Detect 2 (Note 4)
nDCD2
I
153
Ring Indicator 2 (Note 4)
nRI2
I
IDE1 INTERFACE
23
IDE1 Enable (Note 4)
nIDE1_OE
O4
24
IDE1 Chip Select 0 (Note 4)
nHDCS0
O24
25
IDE1 Chip Select 1 (Note 4)
nHDCS1
O24
30
IOR Output (Note 4)
nIOROP
O24
31
IOW Output (Note 4)
nIOWOP
O24
26
IDE1 Interrupt Request (Note 4)
IDE1_IRQ
I
IDE2 INTERFACE
27
IDE2 Chip Select 2/SA13 (Note 3, 4)
nHDCS2
I/O24
28
IDE2 Chip Select 3/SA14 (Note 3, 4)
nHDCS3
I/O24
29
IDE2 Interrupt Request/SA15 (Note 4)
IDE2_IRQ
I
PARALLEL PORT INTERFACE
138:131
Parallel Port Data Bus
PD[0:7]
140
Printer Select
nSLCTIN
OD24/O24
I/O24
141
Initiate Output
nINIT
OD24/O24
143
Auto Line Feed
nALF
OD24/O24
144
Strobe Signal
nSTB
OD24/O24
128
Busy Signal
BUSY
I
129
Acknowledge Handshake
nACK
I
127
Paper End
PE
I
126
Printer Selected
SLCT
I
142
Error at Printer
nERROR
I
REAL-TIME CLOCK
122
32 Khz Crystal Input
XTAL1
ICLK2
124
32 Khz Crystal Output
XTAL2
OCLK2
121
Battery Voltage
Vbat
KEYBOARD/MOUSE
91
Keyboard Data
KDAT
8
I/OD16P
DESCRIPTION OF PIN FUNCTIONS
PIN NO.
NAME
SYMBOL
BUFFER
TYPE
92
Keyboard Clock
KCLK
I/OD16P
93
Mouse Data
MDAT
I/OD16P
94
Mouse Clock
MCLK
I/OD16P
33
Power On (Note 4)
nPowerOn
I/O24
34
Button Input (Note 4)
Button_In
I/O24
SOFT POWER MANAGEMENT INTERFACE
GENERAL PURPOSE I/O
96
GPI/O; IRQ In (Note 4)
GP10
I/O4
97
GPI/O; IRQ In/IRQ 13 (Note 4)
GP11
I/O4
98
GPI/O; WD Timer Output/IRRX (Note 4)
GP12
I/O4
99
GPI/O; Power Led Output/IRTX (Note 4)
GP13
I/O24
100
GPI/O; GP Address Decode (Note 4)
GP14
I/O4
102
GPI/O; GP Write Strobe (Note 4)
GP15
I/O4
103
GPI/O; Joy Read Strobe/JOYCS (Note 4)
GP16
I/O4
104
GPI/O; Joy Write Strobe (Note 4)
GP17
I/O4
105
GPI/O; IDE2 Output Enable/8042 P20 (Note 4)
GP20
I/O4
106
GPI/O; Serial EEPROM Data In/AB_DATA (Note 4)
GP21
I/O8
107
GPI/O; Serial EEPROM Data Out/AB_CLK (Note 4)
GP22
I/O8
108
GPI/O; Serial EEPROM Clock (Note 4)
GP23
I/O4
109
GPI/O; Serial EEPROM Enable (Note 4)
GP24
I/O4
110
GPI/O; 8042 P21 (Note 4)
GP25
I/O4
ROM Bus (I/O to the SD Bus) (Note 4)
RD[0:7]
I/O4
119
ROM Chip Select (only used for ROM) (Note 4)
nROMCS
120
ROM Output Enable (DIR) (only used for ROM) (Note 4) nROMDIR
BIOS BUFFERS
111:118
Note 0:
Note 1:
I
I
The interrupt request is output on one of the IRQx signals as 024 buffer type. If EPP or
ECP Mode is enabled, this output is pulsed low, then released to allow sharing of interrupts.
In this case, the buffer type is OD24. Refer to the configuration section for more
information.
nCS -This pin is the active low chip select; it must be low for all chip accesses. For 12 bit
addressing, SA0:SA11, this input should be tied to GND. For 16 bit address qualification,
9
Note 2:
Note 3:
Note 4:
address bits SA12:SA15 can be "ORed" together and applied to this pin. If IDE2 is not
used, SA12 can be connected to nCS, pin 27 to SA13, pin 28 to SA14 and pin 29 to SA15.
nYY - The "n" as the first letter of a signal name indicates an "Active Low" signal
nHDCS2 and nHDCS3 require a pull-up to ensure a logic high at power-up when used for
IDE2 until the Active Bit is set to 1.
See Table on the following page for Multifunction Pins with GPI/O and Other Alternate
Functions.
10
Description of Multifunction Pins with GPI/O and Other Alternate Functions
Pin
No.
19
Original
Function
MEDIA_ID1
Alternate
Function 1
GPI/O
Alternate
Function 2
-
Alternate
Function 3
-
Buffer
Type
I/O8
Default
float
Index
Register
GP4
GPI/O
GP40
20
MEDIA_ID0
GPI/O
-
-
I/O8
float
GP4
GP41
23
nIDE1_OE
GPI/O
-
-
I/O4
high
GP4
GP42
24
nHDCS0
GPI/O
-
-
I/O24
high
GP4
GP43
25
nHDCS1
GPI/O
-
-
I/O24
high
GP4
GP44
26
IDE1_IRQ
GPI/O
-
-
I/O8
float
GP4
GP45
30
nIOROP
GPI/O
WDT
I/O24
float
GP4
GP46
31
nIOWOP
GPI/O
Power LED
Output
nSMI
-
I/O24
float
GP4
GP47
33
nPowerOn
GPI/O
-
-
I/O24
active low
open
collector
output
input
GP5
GP51
34
Button_In
GPI/O
-
-
I/O24
GP5
GP50
111
RD0
GPI/O
-
I/O4
RD0
1,4
GP6
GP60
112
RD1
GPI/O
Power LED
Output
WDT
-
I/O4
RD0
1,4
GP6
GP61
113
RD2
GPI/O
8042 - P12
-
I/O4
RD0
1,4
GP6
GP62
114
RD3
GPI/O
8042 - P13
-
I/O4
RD0
1,4
GP6
GP63
RD0
1,4
GP6
GP64
GP6
GP65
GP6
GP66
115
RD4
GPI/O
8042 - P14
-
I/O4
116
RD5
GPI/O
8042 - P15
-
I/O4
RD0
1,4
117
RD6
GPI/O
8042 - P16
-
I/O4
RD0
1,4
RD0
1,4
118
RD7
GPI/O
8042 - P17
-
I/O4
GP6
GP67
GP5
GP53
GP5
GP54
119
nROMCS
GPI/O
-
-
I/O8
nROMCS
1
120
nROMOE
GPI/O
-
-
I/O8
nROMCS
1
I/O8
input
2
GP7
GP70
input
2
GP7
GP71
input
2
GP7
GP72
2,4
GP7
GP73
2
153
154
155
156
nRI2
nDCD2
RXD2
TXD2
GPI/O
GPI/O
GPI/O
GPI/O
-
-
I/O8
I/O8
I/O8
input
157
nDSR2
GPI/O
-
-
I/O8
input,
GP7
GP74
158
nRTS2
GPI/O
-
-
I/O8
input
2,4
GP7
GP75
input
(2)
GP7
GP76
input
2,4
GP7
GP77
159
160
nCTS2
nDTR2
GPI/O
GPI/O
-
-
11
I/O8
I/O8
Pin
No.
27
Original
Function
nHDCS2
Alternate
Function 1
SA13
Alternate
Function 2
-
Alternate
Function 3
-
Buffer
Type
I/O24
Default
float
Index
Register
-
GPI/O
-
28
nHDCS3
SA14
-
-
I/O24
float
-
-
29
IDE2_IRQ
SA15
-
-
I
float
-
-
53
nCS/SA 12
-
-
-
I
input
-
-
96
GPI/O
IRQ in
-
-
I/O4
input
GP1
GP10
97
GPI/O
IRQ in
IRQ13
-
I/O4
input
GP1
GP11
98
GPI/O
-
-
I/O4
input
GP1
GP12
99
GPI/O
-
-
I/O24
input
GP1
GP13
100
GPI/O
-
-
I/O4
input
GP1
GP14
102
GPI/O
-
-
I/O4
input
GP1
GP15
103
GPI/O
JOYCS
-
I/O4
input
GP1
GP16
104
GPI/O
-
-
I/O4
input
GP1
GP17
105
GPI/O
8042 P20
-
I/O4
input
GP2
GP20
106
GPI/O
WDT
Timer
Output/
IRRX
Power LED
Output/
IRTX
GP
Address
Decode
GP Write
Strobe
Joy Read
Strobe
Joy Write
Strobe
IDE2
Output
Enable
Serial
EEPROM
Data In
AB_DATA
-
input
GP2
GP21
107
GPI/O
Serial
EEPROM
Data Out
AB_CLK
-
input
GP2
GP22
108
GPI/O
-
-
input
GP2
GP23
109
GPI/O
-
-
I/O4
input
GP2
GP24
110
GPI/O
Serial
EEPROM
Clock
Serial
EEPROM
Enable
8042 P21
I/O8
/OD8
(EN1)
I/O8
/OD8
(EN1)
I/O4
-
-
I/O4
input
GP2
GP25
Note 1: At power-up, RD0-RD7, nROMCS and nROMOE function as the XD Bus. To use
RD0-RD7 for functions other than the XD Bus, nROMCS must stay high until
those pins are finished being reprogrammed.
Note 2: These pins are input (high-z) until programmed for second serial port.
Note 3: This is the trickle voltage input pin for the FDC37C93xAPM.
Note 4: These pins cannot be programmed as open drain pins in their original function.
Note:
No pins in their original function can be programmed as inverted input or inverted output.
12
BUFFER TYPE DESCRIPTIONS
BUFFER TYPE
I
IS
I/OD16P
I/O24
I/O4
O4
O8SR
O16SR
O20
O24
OD24
OD48
ICLK
ICLK2
OCLK2
DESCRIPTION
Input, TTL compatible.
Input with Schmitt trigger.
Input/Output, 16mA sink, 90uA pull-up.
Input/Output, 24mA sink, 12mA source.
Input/Output, 4mA sink, 2mA source.
Output, 4mA sink, 2mA source.
Output, 8mA sink, 4mA source with Slew Rate Limiting.
Output, 16mA sink, 8mA source with Slew Rate Limiting.
Output, 20mA sink, 10mA source.
Output, 24mA sink, 12mA source.
Output, Open Drain, 24mA sink.
Output, Open Drain, 48mA sink.
Clock Input
Clock Input
Clock Output
13
nGPA
nGPCS* nGPWR*
nSMI* IRQ13*
nPowerOn
Button_In
VTR
SOFT
POWER
MANAGEMENT
SMI
ACPI/SCI
POWER
MANAGEMENT
BIOS
BUFFER
nROMDIR
nROMCS
RD[0:7]
DECODER
PD0-7
MULTI-MODE
PARALLEL
PORT/FDC
MUX
DATA BUS
AB_DATA*
AB_CLK*
BUSY, SLCT, PE,
nERROR, nACK
nSTB, nSLCTIN,
ACCESS.bus
nINIT, nALF
GENERAL
PURPOSE
I/O
ADDRESS BUS
DATAIN*
SERIAL
EEPROM
DATAOUT*
CLK*, ENABLE*
CONFIGURATION
REGISTERS
nIOR
16C550
COMPATIBLE
SERIAL
PORT 1
GP1[0:7]*
GP2[0:5]*
GP[4[0:7]*, GP5[0:1,3:4]*,
GP6[0:7]*, GP7[0:7]*
TXD1, nCTS1, nRTS1
RXD1
nDSR1, nDCD1, nRI1, nDTR1
nIOW
CONTROL BUS
AEN
IRRX*, IRTX*
SA[0:12] (nCS)
WDATA
SA[13-15]
WCLOCK
HOST
SMSC
PROPRIETARY
82077
COMPATIBLE
VERTICAL
FLOPPYDISK
CONTROLLER
CORE
CPU
SD[O:7]
16C550
COMPATIBLE
SERIAL
PORT 2 WITH
INFRARED
INTERFACE
DRQ[0:3]
nDACK[0:3]
DIGITAL
DATA
SEPARATOR
WITH WRITE
PRECOMPENSATION
INTERFACE
RDATA
IRQ[1,3-12,14,15]
GEN
8042
IOCHRDY
Vcc
Vss
nDSR2, nDCD2, nRI2, nDTR2
nHDCS2,3
IDE2_IRQ
nIDE1_OE
nIOWOP
nIOROP
nHDCS0, nHDCS1
CLOCK
RESET_DRV
RXD2(IRRX)
IDE1_IRQ
IDE
RCLOCK
TC
IDE2
OPTIONAL
TXD2(IRTX), nCTS2, nRTS2
nINDEX DENSEL nDS0,1
nTRK0
nMTR0,1
nDIR
nWDATA nRDATA
nDSKCHG
nSTEP DRVDEN0
nWRPRT
nHDSEL DRVDEN1
ICLOCK
nWGATE
(14.318)
MID0, MID1
HCLK
CLKO[1:3]
(14.318)
16CLK
*Multi-Function I/O Pin - Optional
RTC
FDC37C93xAPM BLOCK DIAGRAM
14
KCLK
KDATA
MCLK
MDATA
P20*, P21*
P12*, P13*, P14*,P15*, P16*, P17*
XTAL1,2
VBAT
FUNCTIONAL DESCRIPTION
SUPER I/O REGISTERS
HOST PROCESSOR INTERFACE
The address map, shown below in Table 1,
shows the addresses of the different blocks of
the Super I/O immediately after power up. The
base addresses of the FDC, IDE, serial and
parallel ports, Bank 2 of the RTC registers,
auxiliary I/O and ACCESS.bus can be moved
via the configuration registers. Some addresses
are used to access more than one register.
The host processor communicates with the
FDC37C93xAPM through a series of read/write
registers. The port addresses for these registers
are shown in Table 1. Register access is
accomplished through programmed I/O or DMA
transfers. All registers are 8 bits wide except
the IDE data register at port 1F0H which is 16
bits wide. All host interface output buffers are
capable of sinking a minimum of 12 mA.
Table 1 - Super I/O Block Addresses
LOGICAL
ADDRESS
BLOCK NAME
DEVICE
Base+(0-5) and +(7)
Floppy Disk
0
Base+(0-7)
Serial Port Com 1
4
Base+(0-7)
Serial Port Com 2
5
Parallel Port
SPP
EPP
ECP
ECP+EPP+SPP
3
Base+(0-3)
Base+(0-7)
Base+(0-3), +(400-402)
Base+(0-7), +(400-402)
Base1+(0-7), Base2+(0)
IDE 1
1
Base1+(0-7), Base2+(0)
IDE 2
2
70, 71
Base2+(0,1)
60, 64
RTC
6
KYBD
7
Base1+(0)
Base2+(0)
Base+(0-3)
Aux. I/O
8
ACCESS.bus
9
Base1+(0-11)
ACPI
A
NOTES
IR Support
GPR
GPW
Base2+(0-7)
Note: Refer to the configuration register descriptions for setting the base address
15
FLOPPY DISK CONTROLLER
FDC INTERNAL REGISTERS
The Floppy Disk Controller (FDC) provides the
interface between a host microprocessor and
the floppy disk drives. The FDC integrates the
functions of the Formatter/Controller, Digital
Data Separator, Write Precompensation and
Data Rate Selection logic for an IBM XT/AT
compatible FDC. The true CMOS 765B core
guarantees 100% IBM PC XT/AT compatibility
in addition to providing data overflow and
underflow protection.
The Floppy Disk Controller contains eight
internal registers which facilitate the interfacing
between the host microprocessor and the disk
drive. Table 2 shows the addresses required to
access these registers. Registers other than the
ones shown are not supported. The rest of the
description assumes that the primary addresses
have been selected.
The FDC is compatible to the 82077AA using
SMSC's proprietary floppy disk controller core.
PRIMARY
ADDRESS
3F0
3F1
3F2
3F3
3F4
3F4
3F5
3F6
3F7
3F7
Table 2 - Status, Data and Control Registers
(Shown with base addresses of 3F0 and 370)
SECONDARY
ADDRESS
R/W
REGISTER
370
R
Status Register A (SRA)
371
R
Status Register B (SRB)
372
R/W
Digital Output Register (DOR)
373
R/W
Tape Drive Register (TSR)
374
R
Main Status Register (MSR)
374
W
Data Rate Select Register (DSR)
375
R/W
Data (FIFO)
376
Reserved
377
R
Digital Input Register (DIR)
377
W
Configuration Control Register (CCR)
16
interface pins in PS/2 and Model 30 modes. The
SRA can be accessed at any time when in PS/2
mode. In the PC/AT mode the data bus pins
D0-D7 are held in a high impedance state for a
read of address 3F0.
STATUS REGISTER A (SRA)
Address 3F0 READ ONLY
This register is read-only and monitors the state
of the FINTR
pin
and
several
disk
PS/2 Mode
RESET
COND.
7
INT
PENDING
0
6
nDRV2
5
STEP
N/A
0
4
3
2
nTRK0 HDSEL nINDX
N/A
0
N/A
1
nWP
0
DIR
N/A
0
BIT 4 nTRACK 0
Active low status of the TRK0 disk interface
input.
BIT 0 DIRECTION
Active high status indicating the direction of
head movement. A logic "1" indicates inward
direction; a logic "0" indicates outward direction.
BIT 5 STEP
Active high status of the STEP output disk
interface output pin.
BIT 1 nWRITE PROTECT
Active low status of the WRITE PROTECT disk
interface input. A logic "0" indicates that the disk
is write protected.
BIT 6 nDRV2
Active low status of the DRV2 disk interface
input pin, indicating that a second drive has
been installed.
BIT 2 nINDEX
Active low status of the INDEX disk interface
input.
BIT 7 INTERRUPT PENDING
Active high bit indicating the state of the Floppy
Disk Interrupt output.
BIT 3 HEAD SELECT
Active high status of the HDSEL disk interface
input. A logic "1" selects side 1 and a logic "0"
selects side 0.
17
PS/2 Model 30 Mode
RESET
COND.
7
INT
PENDING
0
6
DRQ
0
5
STEP
F/F
0
4
3
TRK0 nHDSEL
N/A
1
2
INDX
1
WP
0
nDIR
N/A
N/A
1
BIT 4 TRACK 0
Active high status of the TRK0 disk interface
input.
BIT 0 nDIRECTION
Active low status indicating the direction of head
movement. A logic "0" indicates inward
direction; a logic "1" indicates outward direction.
BIT 5 STEP
Active high status of the latched STEP disk
interface output pin. This bit is latched with the
STEP output going active, and is cleared with a
read from the DIR register, or with a hardware
or software reset.
BIT 1 WRITE PROTECT
Active high status of the WRITE PROTECT disk
interface input. A logic "1" indicates that the disk
is write protected.
BIT 2 INDEX
Active high status of the INDEX disk interface
input.
BIT 6 DMA REQUEST
Active high status of the DRQ output pin.
BIT 7 INTERRUPT PENDING
Active high bit indicating the state of the Floppy
Disk Interrupt output.
BIT 3 nHEAD SELECT
Active low status of the HDSEL disk interface
input. A logic "0" selects side 1 and a logic "1"
selects side 0.
18
Model 30 modes. The SRB can be accessed at
any time when in PS/2 mode. In the PC/AT
mode the data bus pins D0 - D7 are held in a
high impedance state for a read of address 3F1.
STATUS REGISTER B (SRB)
Address 3F1 READ ONLY
This register is read-only and monitors the state
of several disk interface pins in PS/2 and
PS/2 Mode
RESET
COND.
7
1
6
1
1
1
5
4
3
2
DRIVE WDATA RDATA WGATE
SEL0 TOGGLE TOGGLE
0
0
0
0
1
MOT
EN1
0
0
MOT
EN0
0
BIT 4 WRITE DATA TOGGLE
Every inactive edge of the WDATA input causes
this bit to change state.
BIT 0 MOTOR ENABLE 0
Active high status of the MTR0 disk interface
output pin. This bit is low after a hardware reset
and unaffected by a software reset.
BIT 5 DRIVE SELECT 0
Reflects the status of the Drive Select 0 bit of
the DOR (address 3F2 bit 0). This bit is cleared
after a hardware reset and it is unaffected by a
software reset.
BIT 1 MOTOR ENABLE 1
Active high status of the MTR1 disk interface
output pin. This bit is low after a hardware reset
and unaffected by a software reset.
BIT 6 RESERVED
Always read as a logic "1".
BIT 2 WRITE GATE
Active high status of the WGATE disk interface
output.
BIT 7 RESERVED
Always read as a logic "1".
BIT 3 READ DATA TOGGLE
Every inactive edge of the RDATA input causes
this bit to change state.
19
PS/2 Model 30 Mode
RESET
COND.
7
nDRV2
6
nDS1
5
nDS0
N/A
1
1
4
WDATA
F/F
0
3
RDATA
F/F
0
2
WGATE
F/F
0
1
nDS3
0
nDS2
1
1
BIT 4 WRITE DATA
Active high status of the latched WDATA output
signal. This bit is latched by the inactive going
edge of WDATA and is cleared by the read of
the DIR register. This bit is not gated with
WGATE.
BIT 0 nDRIVE SELECT 2
Active low status of the DS2 disk interface
output.
BIT 1 nDRIVE SELECT 3
Active low status of the DS3 disk interface
output.
BIT 5 nDRIVE SELECT 0
Active low status of the DS0 disk interface
output.
BIT 2 WRITE GATE
Active high status of the latched WGATE output
signal. This bit is latched by the active going
edge of WGATE and is cleared by the read of
the DIR register.
BIT 6 nDRIVE SELECT 1
Active low status of the DS1 disk interface
output.
BIT 3 READ DATA
Active high status of the latched RDATA output
signal. This bit is latched by the inactive going
edge of RDATA and is cleared by the read of the
DIR register.
BIT 7 nDRV2
Active low status of the DRV2 disk interface
input.
20
DIGITAL OUTPUT REGISTER (DOR)
also contains the enable for the DMA logic and a
software reset bit. The contents of the DOR are
unaffected by a software reset. The DOR can
be written to at any time.
Address 3F2 READ/WRITE
The DOR controls the drive select and motor
enables of the disk interface outputs. It
RESET
COND.
7
MOT
EN3
0
6
MOT
EN2
0
5
MOT
EN1
0
4
MOT
EN0
0
3
2
1
0
DMAEN nRESE DRIVE DRIVE
T
SEL1
SEL0
0
0
0
0
BIT 0 and 1 DRIVE SELECT
These two bits are binary encoded for the four drive
selects DS0 -DS3, thereby allowing only one drive to
be selected at one time.
BIT 4 MOTOR ENABLE 0
This bit controls the MTR0 disk interface output. A
logic "1" in this bit will cause the output pin to go
active.
BIT 2 nRESET
A logic "0" written to this bit resets the floppy disk
controller. This reset will remain active until a logic
"1" is written to this bit. This software reset does not
affect the DSR and CCR registers, nor does it affect
the other bits of the DOR register. The minimum
reset duration required is 100ns, therefore toggling
this bit by consecutive writes to this register is a valid
method of issuing a software reset.
BIT 5 MOTOR ENABLE 1
This bit controls the MTR1 disk interface output. A
logic "1" in this bit will cause the output pin to go
active.
BIT 3 DMAEN
PC/AT and Model 30 Mode:
Writing this bit to logic "1" will enable the DRQ,
nDACK, TC and FINTR outputs. When this bit is a a
logic "0" it disables the nDACK and TC inputs and
holds the DRQ and FINTR outputs in a high
impedance state. This bit is a logic "0" after a reset
and in these modes.
BIT 7 MOTOR ENABLE 3
This bit controls the MTR3 disk interface output. A
logic "1" in this bit causes the output to go active.
BIT 6 MOTOR ENABLE 2
This bit controls the MTR2 disk interface output. A
logic "1" in this bit will cause the output pin to go
active.
Table 3 - Drive Activation Values
PS/2 Mode: In this mode the DRQ, nDACK, TC and
FINTR pins are always enabled. During a reset, the
DRQ, nDACK, TC, and FINTR pins will remain
enabled, but this bit will be cleared to a logic "0".
21
DRIVE
DOR VALUE
0
1
2
3
1CH
2DH
4EH
8FH
TAPE DRIVE REGISTER (TDR)
Table 4 - Tape Select Bits
Address 3F3 READ/WRITE
This register is included for 82077 software
compatability. The robust digital data separator
used in the FDC does not require its
characteristics modified for tape support. The
contents of this register are not used internal to
the device.
The TDR is unaffected by a
software reset.
Bits 2-7 are tri-stated when
read in this mode.
TAPE SEL1
TAPE SEL2
DRIVE
SELECTED
0
0
1
1
0
1
0
1
None
1
2
3
Table 5 - Internal 2 Drive Decode - Normal
DRIVE SELECT
MOTOR ON OUTPUTS
DIGITAL OUTPUT REGISTER
OUTPUTS (ACTIVE LOW)
(ACTIVE LOW)
Bit 7 Bit 6 Bit 5 Bit 4 Bit1 Bit 0
nDS1
nDS0
nMTR1
nMTR0
X
X
X
1
0
0
1
0
nBIT 5
nBIT 4
X
X
1
X
0
1
0
1
nBIT 5
nBIT 4
X
1
X
X
1
0
1
1
nBIT 5
nBIT 4
1
X
X
X
1
1
1
1
nBIT 5
nBIT 4
0
0
0
0
X
X
1
1
nBIT 5
nBIT 4
Table 6 - Internal 2 Drive Decode - Drives 0 and 1 Swapped
DRIVE SELECT OUTPUTS MOTOR ON OUTPUTS
DIGITAL OUTPUT REGISTER
(ACTIVE LOW)
(ACTIVE LOW)
Bit 7 Bit 6 Bit 5 Bit 4 Bit1 Bit 0
nDS1
nDS0
nMTR1
nMTR0
X
X
X
1
0
0
0
1
nBIT 4
nBIT 5
X
X
1
X
0
1
1
0
nBIT 4
nBIT 5
X
1
X
X
1
0
1
1
nBIT 4
nBIT 5
1
X
X
X
1
1
1
1
nBIT 4
nBIT 5
0
0
0
0
X
X
1
1
nBIT 4
nBIT 5
22
Normal Floppy Mode
Normal mode. Register 3F3 contains only bits 0 and 1. When this register is read, bits 2 - 7 are a
high impedance.
REG 3F3
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0
Tri-state
Tri-state
Tri-state
Tri-state
Tri-state
Tri-state
tape sel1
tape sel0
DB3
DB2
DB1
DB0
tape sel1
tape sel0
Enhanced Floppy Mode 2 (OS2)
Register 3F3 for Enhanced Floppy Mode 2 operation.
REG 3F3
DB7
DB6
Media
ID1
Media
ID0
DB5
DB4
Drive Type ID
For this mode, MEDIA_ID[1:0] pins are gated
into bits 6 and 7 of the 3F3 register. These two
bits are not affected by a hard or soft reset.
Note: L0-CRF1-B5 = Logical Device
Configuration Register F1, Bit 5
BIT 7 MEDIA ID 1 READ ONLY (Pin 19) (See
Table 7)
BIT 1 AND 0 - TAPE DRIVE SELECT
(READ/WRITE). Same as in Normal and
Enhanced Floppy Mode. 1.
DRIVE TYPE ID - These bits
the bits of L0-CRF1. Which
are depends on the last drive
Digital Output Register (3F2).
Table 7 - Media ID1
MEDIA ID1
INPUT
Table 8 - Media ID0
MEDIA ID0
BIT 7
Pin 19
L0-CRF1-B5
=0
L0-CRF1-B5
=1
0
0
1
1
1
0
0,
BIT 3 and 2 FLOPPY BOOT DRIVE - These
bits reflect the value of L0-CRF1. Bit 3 = L0CRF1-B7. Bit 2 = L0-CRF1-B6.
BIT 6 MEDIA ID 0 READ ONLY (Pin 20) (See
Table 8)
BIT 5 and 4
reflect two of
two bits these
selected in the
(See Table 9)
Floppy Boot Drive
INPUT
Pin 20
0
1
23
BIT 6
CRF1-B4
=0
CRF1-B4
=1
0
1
1
0
Table 9 - Drive Type ID
DIGITAL OUTPUT REGISTER
REGISTER 3F3 - DRIVE TYPE ID
Bit 1
Bit 0
Bit 5
Bit 4
0
0
L0-CRF2 - B1
L0-CRF2 - B0
0
1
L0-CRF2 - B3
L0-CRF2 - B2
1
0
L0-CRF2 - B5
L0-CRF2 - B4
1
1
L0-CRF2 - B7
L0-CRF2 - B6
Note: L0-CRF2-Bx = Logical Device 0, Configuration Register F2, Bit x.
24
30 and Microchannel applications.
Other
applications can set the data rate in the DSR.
The data rate of the floppy controller is the most
recent write of either the DSR or CCR. The DSR
is unaffected by a software reset. A hardware
reset will set the DSR to 02H, which
corresponds to the default precompensation
setting and 250 Kbps.
DATA RATE SELECT REGISTER (DSR)
Address 3F4 WRITE ONLY
This register is write only. It is used to program
the data rate, amount of write precompensation,
power down status, and software reset. The
data
rate
is
programmed
using
the
Configuration Control Register (CCR) not the
DSR,
for
PC/AT and PS/2 Model
RESET
COND.
7
6
S/W POWER
RESET DOWN
0
0
5
0
0
4
PRECOMP2
0
3
PRECOMP1
0
2
1
0
PRE- DRATE DRATE
COMP0 SEL1
SEL0
0
1
0
separator circuits will be turned off.
The
controller will come out of manual low power
mode after a software reset or access to the
Data Register or Main Status Register.
BIT 0 and 1 DATA RATE SELECT
These bits control the data rate of the floppy
controller.
See Table 11 for the settings
corresponding to the individual data rates. The
data rate select bits are unaffected by a
software reset, and are set to 250 Kbps after a
hardware reset.
BIT 7 SOFTWARE RESET
This active high bit has the same function as the
DOR RESET (DOR bit 2) except that this bit is
self clearing.
BIT 2 - 4 PRECOMPENSATION SELECT
These three bits select the value of write
precompensation that will be applied to the
WDATA output signal. Table 10 shows the
precompensation values for the combination of
these bits settings. Track 0 is the default
starting track number to start precompensation.
this starting track number can be changed by
the configure command.
Table 10 - Precompensation Delays
PRECOMP
432
111
001
010
011
100
101
110
000
BIT 5 UNDEFINED
Should be written as a logic "0".
BIT 6 LOW POWER
A logic "1" written to this bit will put the floppy
controller into manual low power mode. The
floppy
controller
clock
and data
PRECOMPENSATION
DELAY (nsec)
<2Mbps
2Mbps*
0.00
41.67
83.34
125.00
166.67
208.33
250.00
Default
0
20.8
41.7
62.5
83.3
104.2
125
Default
Default: See Table 12
*2Mbps data rate is only available if VCC = 5V.
25
DRIVE RATE
Table 11 - Data Rates
DATA RATE
DATA RATE
DRATE(1)
DENSEL
DRT1
DRT0
SEL1
SEL0
MFM
FM
1
0
0
0
1
1
1Meg
---
0
0
0
0
500
250
1
1
1
1
0
0
0
0
0
1
300
150
0
0
1
0
0
1
0
250
125
0
1
0
0
1
1
1
1Meg
---
1
1
1
0
1
0
0
500
250
1
0
0
0
0
1
0
1
500
250
0
0
1
1
1
0
250
125
0
1
0
1
0
1
1
1Meg
---
1
1
1
1
0
0
0
500
250
1
0
0
1
0
0
1
2Meg
---
0
0
1
1
0
1
0
250
125
0
1
0
Drive Rate Table (Recommended) 00 = 360K, 1.2M, 720K, 1.44M and 2.88M Vertical Format
01 = 3-Mode Drive
10 = 2 Meg Tape
Note 1:
The DRATE and DENSEL values are mapped onto the DRVDEN pins.
Table 12 - DRVDEN Mapping
DRVDEN1 (1)
DRVDEN0 (1)
DT1
DT0
0
0
DRATE0
1
0
DRATE0
DRATE1
0
1
DRATE0
nDENSEL
1
1
DRATE1
DRATE0
DENSEL
26
DRIVE TYPE
4/2/1 MB 3.5"
2/1 MB 5.25" FDDS
2/1.6/1 MB 3.5" (3-MODE)
PS/2
Table 13 - Default Precompensation Delays
DATA RATE
PRECOMPENSATION
DELAYS
2 Mbps*
1 Mbps
500 Kbps
300 Kbps
250 Kbps
20.8 ns
41.67 ns
125 ns
125 ns
125 ns
*The 2Mbps data rate is only available if VCC = 5V.
27
read at any time. The MSR indicates when the
disk controller is ready to receive data via the
Data Register. It should be read before each
byte transferring to or from the data register
except in DMA mode. No delay is required
when reading the MSR after a data transfer.
MAIN STATUS REGISTER
Address 3F4 READ ONLY
The Main Status Register is a read-only register
and indicates the status of the disk controller.
The
Main
Status
Register
can be
7
RQM
6
DIO
5
NON
DMA
4
CMD
BUSY
3
DRV3
BUSY
2
DRV2
BUSY
1
DRV1
BUSY
0
DRV0
BUSY
BIT 5 NON-DMA
This mode is selected in the SPECIFY
command and will be set to a “1” during the
execution phase of a command. This is for
polled data transfers and helps differentiate
between the data transfer phase and the reading
of result bytes.
BIT 0-3 DRVx BUSY
These bits are set to “1”s when a drive is in the
seek portion of a command, including implied
and overlapped seeks and recalibrates.
BIT 4 COMMAND BUSY
This bit is set to a “1” when a command is in
progress. This bit will go active after the
command byte has been accepted and goes
inactive at the end of the results phase. If there
is no result phase (Seek, Recalibrate
commands), this bit is returned to a “0” after the
last command byte.
BIT 6 DIO
Indicates the direction of a data transfer once a
RQM is set. A “1” indicates a read and a “0”
indicates a write is required.
BIT 7 RQM
Indicates that the host can transfer data if set to
a “1”. No access is permitted if set to a “0”.
28
FIFO. The data is based upon the following
formula:
DATA REGISTER (FIFO)
Address 3F5 READ/WRITE
All command parameter information, disk data
and result status are transferred between the
host processor and the floppy disk controller
through the Data Register.
Threshold # x
1
x8
At the start of a command, the FIFO action is
always disabled and command parameters
must be sent based upon the RQM and DIO bit
settings. As the command execution phase is
entered, the FIFO is cleared of any data to
ensure that invalid data is not transferred.
Data transfers are governed by the RQM and
DIO bits in the Main Status Register.
The Data Register defaults to FIFO disabled
mode after any form of reset. This maintains
PC/AT hardware compatibility.
The default
values can be changed through the Configure
command (enable full FIFO operation with
threshold control). The advantage of the FIFO
is that it allows the system a larger DMA
latency without causing a disk error. Table 14
gives several examples of the delays with a
An overrun or underrun will terminate the
current command and the transfer of data. Disk
writes will complete the current sector by
generating a 00 pattern and valid CRC. Reads
require the host to remove the remaining data
so that the result phase may be entered.
Table 14 - FIFO Service Delay
FIFO THRESHOLD
MAXIMUM DELAY TO SERVICING
EXAMPLES
AT 2 Mbps* DATA RATE
1 byte
2 bytes
8 bytes
15 bytes
FIFO THRESHOLD
EXAMPLES
1 byte
2 bytes
8 bytes
15 bytes
FIFO THRESHOLD
EXAMPLES
1 byte
2 bytes
8 bytes
15 bytes
- 1.5 µs = DELAY
DATA RATE
1 x 4 µs - 1.5 µs = 2.5 µs
2 x 4 µs - 1.5 µs = 6.5 µs
8 x 4 µs - 1.5 µs = 30.5 µs
15 x 4 µs - 1.5 µs = 58.5 µs
MAXIMUM DELAY TO SERVICING
AT 1 Mbps DATA RATE
1 x 8 µs - 1.5 µs = 6.5 µs
2 x 8 µs - 1.5 µs = 14.5 µs
8 x 8 µs - 1.5 µs = 62.5 µs
15 x 8 µs - 1.5 µs = 118.5 µs
MAXIMUM DELAY TO SERVICING
AT 500 Kbps DATA RATE
1 x 16 µs - 1.5 µs = 14.5 µs
2 x 16 µs - 1.5 µs = 30.5 µs
8 x 16 µs - 1.5 µs = 126.5 µs
15 x 16 µs - 1.5 µs = 238.5 µs
*The 2 Mbps data rate is only available if VCC = 5V.
29
DIGITAL INPUT REGISTER (DIR)
Address 3F7 READ ONLY
This register is read-only in all modes.
PC/AT Mode
RESET
COND.
7
DSK
CHG
N/A
6
5
4
3
2
1
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
BIT 7 DSKCHG
This bit monitors the pin of the same name and
reflects the opposite value seen on the disk
cable.
BIT 0 - 6 UNDEFINED
The data bus outputs D0-6 will remain in a high
impedance state during a read of this register.
PS/2 Mode
RESET
COND.
7
DSK
CHG
N/A
6
1
5
1
4
1
3
1
N/A
N/A
N/A
N/A
2
1
0
DRATE DRATE nHIGH
SEL1
SEL0 nDENS
N/A
N/A
1
software reset and are set to 250 Kbps after a
hardware reset.
BIT 0 nHIGH DENS
This bit is low whenever the 500 Kbps or 1 Mbps
data rates are selected, and high when 250
Kbps and 300 Kbps are selected.
BIT 3 - 6 UNDEFINED
Always read as a logic "1"
BIT 1 and 2 DATA RATE SELECT
These bits control the data rate of the floppy
controller.
See Table 11 for the settings
corresponding to the individual data rates. The
data rate select bits are unaffected by a
BIT 7 DSKCHG
This bit monitors the pin of the same name and
reflects the opposite value seen on the disk
cable.
30
Model 30 Mode
RESET
COND.
7
DSK
CHG
N/A
6
0
5
0
4
0
0
0
0
3
2
1
0
DMAEN NOPREC DRATE DRATE
SEL1
SEL0
0
0
1
0
BIT 3 DMAEN
This bit reflects the value of DMAEN bit set in
the DOR register bit 3.
BIT 0 and 1 DATA RATE SELECT
These bits control the data rate of the floppy
controller.
See Table 11 for the settings
corresponding to the individual data rates. The
data rate select bits are unaffected by a
software reset, and are set to 250 Kbps after a
hardware reset.
BIT 4 - 6 UNDEFINED
Always read as a logic "0"
BIT 7 DSKCHG
This bit monitors the pin of the same name and
reflects the opposite value seen on the pin.
BIT 2 NOPREC
This bit reflects the value of NOPREC bit set in
the CCR register.
31
CONFIGURATION CONTROL REGISTER (CCR)
Address 3F7 WRITE ONLY
PC/AT and PS/2 Modes
RESET
COND.
7
6
5
4
3
2
N/A
N/A
N/A
N/A
N/A
N/A
1
0
DRATE DRATE
SEL1
SEL0
1
0
BIT 2 - 7 RESERVED
Should be set to a logical "0"
BIT 0 and 1 DATA RATE SELECT 0 and 1
These bits determine the data rate of the floppy
controller. See Table 11 for the appropriate
values.
PS/2 Model 30 Mode
RESET
COND.
7
6
5
4
3
N/A
N/A
N/A
N/A
N/A
BIT 0 and 1 DATA RATE SELECT 0 and 1
These bits determine the data rate of the floppy
controller. See Table 11 for the appropriate
values.
2
1
0
NOPREC DRATE DRATE
SEL1
SEL0
N/A
1
0
BIT 3 - 7 RESERVED
Should be set to a logical "0"
Table 12 shows the state of the DENSEL pin.
The DENSEL pin is set high after a hardware
reset and is unaffected by the DOR and the
DSR resets.
BIT 2 NO PRECOMPENSATION
This bit can be set by software, but it has no
functionality. It can be read by bit 2 of the DSR
when in Model 30 register mode. Unaffected by
software reset.
32
STATUS REGISTER ENCODING
During the Result Phase of certain commands, the Data Register contains data bytes that give the
status of the command just executed.
BIT NO.
SYMBOL
Table 15 - Status Register 0
NAME
DESCRIPTION
7,6
IC
Interrupt
Code
00 - Normal termination of command. The specified
command was properly executed and completed
without error.
01 - Abnormal termination of command. Command
execution was started, but was not successfully
completed.
10 - Invalid command. The requested command
could not be executed.
11 - Abnormal termination caused by Polling.
5
SE
Seek End
The FDC completed a Seek, Relative Seek or
Recalibrate command (used during a Sense Interrupt
Command).
4
EC
Equipment
Check
The TRK0 pin failed to become a "1" after:
1. 80 step pulses in the Recalibrate command.
2. The Relative Seek command caused the FDC to
step outward beyond Track 0.
H
Head
Address
The current head address.
DS1,0
Drive Select
The current selected drive.
3
2
1,0
Unused. This bit is always "0".
33
BIT NO.
7
SYMBOL
EN
Table 16 - Status Register 1
NAME
DESCRIPTION
End of
Cylinder
6
The FDC tried to access a sector beyond the final
sector of the track (255D). Will be set if TC is not
issued after Read or Write Data command.
Unused. This bit is always "0".
5
DE
Data Error
The FDC detected a CRC error in either the ID field or
the data field of a sector.
4
OR
Overrun/
Underrun
Becomes set if the FDC does not receive CPU or DMA
service within the required time interval, resulting in
data overrun or underrun.
3
Unused. This bit is always "0".
2
ND
No Data
Any one of the following:
1. Read Data, Read Deleted Data command - the
FDC did not find the specified sector.
2. Read ID command - the FDC cannot read the ID
field without an error.
3. Read A Track command - the FDC cannot find
the proper sector sequence.
1
NW
Not Writable
WP pin became a "1" while the FDC is executing a
Write Data, Write Deleted Data, or Format A Track
command.
0
MA
Missing
Any one of the following:
Address Mark 1. The FDC did not detect an ID address mark at the
specified track after encountering the index pulse
from the IDX pin twice.
2. The FDC cannot detect a data address mark or a
deleted data address mark on the specified track.
34
BIT NO.
SYMBOL
Table 17 - Status Register 2
NAME
DESCRIPTION
7
Unused. This bit is always "0".
6
CM
Control Mark
Any one of the following:
1. Read Data command - the FDC encountered a
deleted data address mark.
2. Read Deleted Data command - the FDC
encountered a data address mark.
5
DD
Data Error in
Data Field
The FDC detected a CRC error in the data field.
4
WC
Wrong
Cylinder
The track address from the sector ID field is different
from the track address maintained inside the FDC.
3
Unused. This bit is always "0".
2
Unused. This bit is always "0".
1
BC
Bad Cylinder
The track address from the sector ID field is different
from the track address maintained inside the FDC and
is equal to FF hex, which indicates a bad track with a
hard error according to the IBM soft-sectored format.
0
MD
Missing Data The FDC cannot detect a data address mark or a
Address Mark deleted data address mark.
35
BIT NO.
SYMBOL
Table 18- Status Register 3
NAME
DESCRIPTION
7
6
Unused. This bit is always "0".
WP
Write
Protected
5
4
Unused. This bit is always "1".
T0
Track 0
3
2
1,0
Indicates the status of the WP pin.
Indicates the status of the TRK0 pin.
Unused. This bit is always "1".
HD
Head
Address
Indicates the status of the HDSEL pin.
DS1,0
Drive Select
Indicates the status of the DS1, DS0 pins.
RESET
DOR Reset vs. DSR Reset (Software Reset)
There are three sources of system reset on the
FDC: the RESET pin of the FDC, a reset
generated via a bit in the DOR, and a reset
generated via a bit in the DSR. At power on, a
Power On Reset initializes the FDC. All resets
take the FDC out of the powerdown state.
These two resets are functionally the same.
Both will reset the FDC core, which affects drive
status information and the FIFO circuits. The
DSR reset clears itself automatically while the
DOR reset requires the host to manually clear it.
DOR reset has precedence over the DSR reset.
The DOR reset is set automatically upon a pin
reset. The user must manually clear this reset
bit in the DOR to exit the reset state.
All operations are terminated upon a RESET,
and the FDC enters an idle state. A reset while
a disk write is in progress will corrupt the data
and CRC.
MODES OF OPERATION
On exiting the reset state, various internal
registers are cleared, including the Configure
command information, and the FDC waits for a
new command. Drive polling will start unless
disabled by a new Configure command.
The FDC has three modes of operation, PC/AT
mode, PS/2 mode and Model 30 mode. These
are determined by the state of the IDENT and
MFM bits 6 and 5 respectively of CRxx.
PC/AT mode - (IDENT high, MFM a "don't
care")
The PC/AT register set is enabled, the DMA
enable bit of the DOR becomes valid (FINTR
and DRQ can be hi Z), and TC and DENSEL
become active high signals.
RESET Pin (Hardware Reset)
The RESET pin is a global reset and clears all
registers except those programmed by the
Specify command.
The DOR reset bit is
enabled and must be cleared by the host to exit
the reset state.
36
PS/2 mode - (IDENT low, MFM high)
This mode supports the PS/2 models 50/60/80
configuration and register set. The DMA bit of
the DOR becomes a "don't care" (FINTR and
DRQ are always valid), TC and DENSEL
become active low.
Burst mode is enabled via Bit[1] of CRF0 in
Logical Device 0. Setting Bit[1]=0 enables burst
mode; the default is Bit[1]=1, for non-burst
mode.
Model 30 mode - (IDENT low, MFM low)
This mode supports PS/2 Model 30
configuration and register set. The DMA enable
bit of ther DOR becomes valid (FINTR and DRQ
can be hi Z), TC is active high and DENSEL is
active low.
For simplicity, command handling in the FDC
can be divided into three phases: Command,
Execution, and Result. Each phase is described
in the following sections.
DMA TRANSFERS
After a reset, the FDC enters the command
phase and is ready to accept a command from
the host. For each of the commands, a defined
set of command code bytes and parameter
bytes has to be written to the FDC before the
command phase is complete. (Please refer to
Table 19 for the command set descriptions.)
These bytes of data must be transferred in the
order prescribed.
CONTROLLER PHASES
Command Phase
DMA transfers are enabled with the Specify
command and are initiated by the FDC by
activating the FDRQ pin during a data transfer
command. The FIFO is enabled directly by
asserting nDACK and addresses need not be
valid.
Note that if the DMA controller (i.e. 8237A) is
programmed to function in verify mode, a
pseudo read is performed by the FDC based
only on nDACK. This mode is only available
when the FDC has been configured into byte
mode (FIFO disabled) and is programmed to do
a read. With the FIFO enabled, the FDC can
perform the above operation by using the new
Verify command; no DMA operation is needed.
Before writing to the FDC, the host must
examine the RQM and DIO bits of the Main
Status Register. RQM and DIO must be equal
to "1" and "0" respectively before command
bytes may be written. RQM is set false by the
FDC after each write cycle until the received
byte is processed. The FDC asserts RQM again
to request each parameter byte of the command
unless an illegal command condition is
detected.
After the last parameter byte is
received, RQM remains "0" and the FDC
automatically enters the next phase as defined
by the command definition.
The FDC37C93xAPM supports two DMA
transfer modes for the FDC: Single Transfer and
Burst Transfer.
In the case of the single
transfer, the DMA Req goes active at the start of
the DMA cycle, and the DMA Req is deasserted
after the nDACK. In the case of the burst
transfer, the Req is held active until the last
transfer (independent of nDACK). See timing
diagrams for more information.
The FIFO is disabled during the command
phase to provide for the proper handling of the
"Invalid Command" condition.
37
full sector have been placed in the FIFO. The
FINT pin can be used for interrupt-driven
systems, and RQM can be used for polled
systems. The host must respond to the request
by reading data from the FIFO. This process is
repeated until the last byte is transferred out of
the FIFO. The FDC will deactivate the FINT pin
and RQM bit when the FIFO becomes empty.
Execution Phase
All data transfers to or from the FDC occur
during the execution phase, which can proceed
in DMA or non-DMA mode as indicated in the
Specify command.
After a reset, the FIFO is disabled. Each data
byte is transferred by an FINT or FDRQ
depending on the DMA mode. The Configure
command can enable the FIFO and set the
FIFO threshold value.
Non-DMA Mode - Transfers from the Host to the
FIFO
The FINT pin and RQM bit in the Main Status
Register are activated upon entering the
execution phase of data transfer commands.
The host must respond to the request by writing
data into the FIFO. The FINT pin and RQM bit
remain true until the FIFO becomes full. They
are set true again when the FIFO has
<threshold> bytes remaining in the FIFO. The
FINT pin will also be deactivated if TC and
nDACK both go inactive. The FDC enters the
result phase after the last byte is taken by the
FDC from the FIFO (i.e. FIFO empty condition).
The following paragraphs detail the operation of
the FIFO flow control. In these descriptions,
<threshold> is defined as the number of bytes
available to the FDC when service is requested
from the host and ranges from 1 to 16. The
parameter FIFOTHR, which the user programs,
is one less and ranges from 0 to 15.
A low threshold value (i.e. 2) results in longer
periods of time between service requests, but
requires faster servicing of the request for both
read and write cases. The host reads (writes)
from (to) the FIFO until empty (full), then the
transfer request goes inactive. The host must
be very responsive to the service request. This
is the desired case for use with a "fast" system.
DMA Mode - Transfers from the FIFO to the
Host
The FDC activates the DDRQ pin when the
FIFO contains (16 - <threshold>) bytes, or the
last byte of a full sector transfer has been
placed in the FIFO. The DMA controller must
respond to the request by reading data from the
FIFO. The FDC will deactivate the DDRQ pin
when the FIFO becomes empty. FDRQ goes
inactive after nDACK goes active for the last
byte of a data transfer (or on the active edge of
nIOR, on the last byte, if no edge is present on
nDACK). A data underrun may occur if FDRQ
is not removed in time to prevent an unwanted
cycle.
A high value of threshold (i.e. 12) is used with a
"sluggish" system by affording a long latency
period after a service request, but results in
more frequent service requests.
Non-DMA Mode - Transfers from the FIFO to
the Host
The FINT pin and RQM bits in the Main Status
Register are activated when the FIFO contains
(16-<threshold>) bytes or the last bytes of a
38
complete the sector as if a hardware TC was
received. The only difference between these
implicit functions and TC is that they return
"abnormal termination" result status.
Such
status indications can be ignored if they were
expected.
DMA Mode - Transfers from the Host to the
FIFO
The FDC activates the FDRQ pin when entering
the execution phase of the data transfer
commands. The DMA controller must respond
by activating the nDACK and nIOW pins and
placing data in the FIFO. FDRQ remains active
until the FIFO becomes full. FDRQ is again set
true when the FIFO has <threshold> bytes
remaining in the FIFO. The FDC will also
deactivate the FDRQ pin when TC becomes true
(qualified by nDACK), indicating that no more
data is required. FDRQ goes inactive after
nDACK goes active for the last byte of a data
transfer (or on the active edge of nIOW of the
last byte, if no edge is present on nDACK). A
data overrun may occur if FDRQ is not removed
in time to prevent an unwanted cycle.
Note that when the host is sending data to the
FIFO of the FDC, the internal sector count will
be complete when the FDC reads the last byte
from its side of the FIFO. There may be a delay
in the removal of the transfer request signal of
up to the time taken for the FDC to read the last
16 bytes from the FIFO. The host must tolerate
this delay.
Result Phase
The generation of FINT determines the
beginning of the result phase. For each of the
commands, a defined set of result bytes has to
be read from the FDC before the result phase is
complete. These bytes of data must be read out
for another command to start.
Data Transfer Termination
The FDC supports terminal count explicitly
through the TC pin and implicitly through the
underrun/overrun and end-of-track (EOT)
functions. For full sector transfers, the EOT
parameter can define the last sector to be
transferred in a single or multi-sector transfer.
RQM and DIO must both equal "1" before the
result bytes may be read. After all the result
bytes have been read, the RQM and DIO bits
switch to "1" and "0" respectively and the CB bit
is cleared, indicating that the FDC is ready to
accept the next command.
If the last sector to be transferred is a partial
sector, the host can stop transferring the data in
mid-sector, and the FDC will continue to
39
COMMAND SET/DESCRIPTIONS
interrupt is issued. The user sends a Sense
Interrupt Status command which returns an
invalid command error. Refer to Table 19 for
explanations of the various symbols used. Table
20 lists the required parameters and the results
associated with each command that the FDC is
capable of performing.
Commands can be written whenever the FDC is
in the command phase. Each command has a
unique set of needed parameters and status
results. The FDC checks to see that the first
byte is a valid command and, if valid, proceeds
with the command. If it is invalid, an
Table 19 - Description of Command Symbols
SYMBOL
NAME
DESCRIPTION
C
Cylinder Address
The currently selected address; 0 to 255.
D
Data Pattern
The pattern to be written in each sector data field during
formatting.
D0, D1, D2,
D3
Drive Select 0-3
Designates which drives are perpendicular drives on the
Perpendicular Mode Command. A "1" indicates a perpendicular
drive.
DIR
Direction Control
If this bit is 0, then the head will step out from the spindle during a
relative seek. If set to a 1, the head will step in toward the spindle.
DS0, DS1
Disk Drive Select
DS1
DS0
DRIVE
0
0
drive 0
0
1
drive 1
1
0
drive 2
1
1
drive 3
By setting N to zero (00), DTL may be used to control the number
of bytes transferred in disk read/write commands. The sector size
(N = 0) is set to 128. If the actual sector (on the diskette) is larger
than DTL, the remainder of the actual sector is read but is not
passed to the host during read commands; during write
commands, the remainder of the actual sector is written with all
zero bytes. The CRC check code is calculated with the actual
sector. When N is not zero, DTL has no meaning and should be
set to FF HEX.
DTL
Special Sector
Size
EC
Enable Count
When this bit is "1" the "DTL" parameter of the Verify command
becomes SC (number of sectors per track).
EFIFO
Enable FIFO
This active low bit when a 0, enables the FIFO. A "1" disables the
FIFO (default).
EIS
Enable Implied
Seek
When set, a seek operation will be performed before executing any
read or write command that requires the C parameter in the
command phase. A "0" disables the implied seek.
40
Table 19 - Description of Command Symbols
SYMBOL
EOT
NAME
End of Track
GAP
DESCRIPTION
The final sector number of the current track.
Alters Gap 2 length when using Perpendicular Mode.
GPL
Gap Length
The Gap 3 size. (Gap 3 is the space between sectors excluding
the VCO synchronization field).
H/HDS
Head Address
Selected head: 0 or 1 (disk side 0 or 1) as encoded in the sector
ID field.
HLT
Head Load Time
The time interval that FDC waits after loading the head and before
initializing a read or write operation. Refer to the Specify
command for actual delays.
HUT
Head Unload
Time
The time interval from the end of the execution phase (of a read or
write command) until the head is unloaded. Refer to the Specify
command for actual delays.
LOCK
Lock defines whether EFIFO, FIFOTHR and PRETRK parameters
of the CONFIGURE COMMAND can be reset to their default
values by a "Software Reset" (reset caused by writing to the
appropriate bits of either tha DSR or DOR).
MFM
MFM/FM Mode
Selector
A “1” selects the double density (MFM) mode. A “0” selects single
density (FM) mode.
MT
Multi-Track
Selector
When set, this flag selects the multi-track operating mode. In this
mode, the FDC treats a complete cylinder under head 0 and 1 as
a single track. The FDC operates as this expanded track started
at the first sector under head 0 and ended at the last sector under
head 1. With this flag set, a multitrack read or write operation will
automatically continue to the first sector under head 1 when the
FDC finishes operating on the last sector under head 0.
41
Table 19 - Description of Command Symbols
SYMBOL
N
NAME
DESCRIPTION
Sector Size Code
This specifies the number of bytes in a sector. If this parameter is
"00", then the sector size is 128 bytes. The number of bytes
transferred is determined by the DTL parameter. Otherwise the
sector size is (2 raised to the "N'th" power) times 128. All values
up to "07" hex are allowable. "07"h would equal a sector size of
16k. It is the user's responsibility to not select combinations that
are not possible with the drive.
N
SECTOR SIZE
00
128 bytes
01
256 bytes
02
512 bytes
03
1024 bytes
NCN
New Cylinder
Number
The desired cylinder number.
ND
Non-DMA Mode
Flag
When set to “1”, indicates that the FDC is to operate in the nonDMA mode. In this mode, the host is interrupted for each data
transfer. When set to “0”, the FDC operates in DMA mode,
interfacing to a DMA controller by means of the DRQ and nDACK
signals.
OW
Overwrite
The bits D0-D3 of the Perpendicular Mode Command can only be
modified if OW is set to “1”. OW is defined in the Lock command.
PCN
Present Cylinder
Number
The current position of the head at the completion of Sense
Interrupt Status command.
POLL
Polling Disable
When set, the internal polling routine is disabled. When clear,
polling is enabled.
PRETRK
Precompensation
Start Track
Number
Programmable from track 00 to FFH.
R
Sector Address
The sector number to be read or written. In multi-sector transfers,
this parameter specifies the sector number of the first sector to be
read or written.
RCN
Relative Cylinder
Number
Relative cylinder offset from present cylinder as used by the
Relative Seek command.
42
Table 19 - Description of Command Symbols
SYMBOL
NAME
DESCRIPTION
SC
Number of
The number of sectors per track to be initialized by the Format
Sectors Per Track command. The number of sectors per track to be verified during a
Verify command when EC is set.
SK
Skip Flag
SRT
Step Rate Interval The time interval between step pulses issued by the FDC
Programmable from 0.5 to 8 milliseconds in increments of 0.5 ms
at the 1 Mbps data rate. Refer to the SPECIFY command for
actual delays.
ST0
Status 0
ST1
Status 1
ST2
Status 2
ST3
Status 3
WGATE
Write Gate
When set to “1”, sectors containing a deleted data address mark
will automatically be skipped during the execution of Read Data. If
Read Deleted is executed, only sectors with a deleted address
mark will be accessed. When set to "0", the sector is read or
written the same as the read and write commands.
Registers within the FDC which store status information after a
command has been executed. This status information is available
to the host during the result phase after command execution.
Alters timing of WE to allow for pre-erase loads in perpendicular
drives.
43
INSTRUCTION SET
Table 20 - Instruction Set
READ DATA
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
MT
MFM
SK
0
0
1
1
0
W
0
0
0
0
0
Command Codes
HDS DS1 DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
REMARKS
Sector ID information prior to
Command execution.
Data transfer between the
FDD and system.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
44
Status information after
Command execution.
Sector ID information after
Command execution.
READ DELETED DATA
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
MT
MFM
SK
0
1
1
0
0
W
0
0
0
0
0
Command Codes
HDS DS1 DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
REMARKS
Sector ID information prior to
Command execution.
Data transfer between the
FDD and system.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
45
Status information after
Command execution.
Sector ID information after
Command execution.
WRITE DATA
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
MT
MFM
0
0
0
1
0
1
W
0
0
0
0
0
Command Codes
HDS DS1 DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
REMARKS
Sector ID information prior to
Command execution.
Data transfer between the
FDD and system.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
46
Status information after
Command execution.
Sector ID information after
Command execution.
WRITE DELETED DATA
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
MT
MFM
0
0
1
0
0
1
W
0
0
0
0
0
HDS
DS1
DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
REMARKS
Command Codes
Sector ID information
prior to Command
execution.
Data transfer between
the FDD and system.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
47
Status information after
Command execution.
Sector ID information
after Command
execution.
READ A TRACK
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
MFM
0
0
0
0
1
0
W
0
0
0
0
0
HDS
DS1
DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
REMARKS
Command Codes
Sector ID information
prior to Command
execution.
Data transfer between
the FDD and system.
FDC reads all of
cylinders' contents from
index hole to EOT.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
48
Status information after
Command execution.
Sector ID information
after Command
execution.
VERIFY
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
W
MT
MFM
SK
1
0
1
1
0
W
EC
0
0
0
0
HDS
DS1
DS0
D2
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------ DTL/SC ------
D1
D0
R
No data transfer takes
place.
Status information after
Command execution.
------- ST0 ------------- ST1 ------------- ST2 -------------- C --------------- H --------------- R --------
R
R
R
R
R
R
Command Codes
Sector ID information
prior to Command
execution.
Execution
Result
REMARKS
Sector ID information
after Command
execution.
-------- N --------
VERSION
DATA BUS
PHASE
R/W
D7
D6
D5
D4
D3
D2
D1
D0
Command
W
0
0
0
1
0
0
0
0
Command Code
Result
R
1
0
0
1
0
0
0
0
Enhanced Controller
49
REMARKS
FORMAT A TRACK
DATA BUS
PHASE
Command
Execution for
Each Sector
Repeat:
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
MFM
0
0
1
1
0
1
W
0
0
0
0
0
HDS
DS1
DS0
REMARKS
Command Codes
W
-------- N --------
Bytes/Sector
W
-------- SC --------
Sectors/Cylinder
W
------- GPL -------
Gap 3
W
-------- D --------
Filler Byte
W
-------- C --------
Input Sector
Parameters
W
-------- H --------
W
-------- R --------
W
-------- N -------FDC formats an entire
cylinder
Result
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
------ Undefined ------
R
------ Undefined ------
R
------ Undefined ------
R
------ Undefined ------
50
Status information after
Command execution
RECALIBRATE
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
0
0
1
1
1
W
0
0
0
0
0
0
DS1
DS0
Execution
REMARKS
Command Codes
Head retracted to Track 0
Interrupt.
SENSE INTERRUPT STATUS
DATA BUS
PHASE
R/W
D7
D6
D5
D4
D3
D2
D1
D0
Command
W
0
0
0
0
1
0
0
0
Result
R
------- ST0 -------
R
------- PCN -------
REMARKS
Command Codes
Status information at the end
of each seek operation.
SPECIFY
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
0
0
0
1
1
W
W
--- SRT ---
--- HUT ---
------ HLT ------
51
ND
REMARKS
Command Codes
SENSE DRIVE STATUS
DATA BUS
PHASE
Command
Result
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
0
0
1
0
0
W
0
0
0
0
0
HDS
DS1
DS0
R
------- ST3 -------
REMARKS
Command Codes
Status information about
FDD
SEEK
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
0
1
1
1
1
W
0
0
0
0
0
HDS
DS1
DS0
W
REMARKS
Command Codes
------- NCN -------
Execution
Head positioned over
proper cylinder on
diskette.
CONFIGURE
DATA BUS
PHASE
Command
Execution
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
1
0
0
1
1
W
0
0
0
0
0
0
0
0
W
0
W
EIS EFIFO
POLL
--- FIFOTHR ---
--------- PRETRK ---------
52
REMARKS
Configure
Information
RELATIVE SEEK
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
1
DIR
0
0
1
1
1
1
W
0
0
0
0
0
HDS
DS1
DS0
W
REMARKS
------- RCN ------DUMPREG
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
0
0
0
1
1
1
0
Execution
Result
R
------ PCN-Drive 0 -------
R
------ PCN-Drive 1 -------
R
------ PCN-Drive 2 -------
R
------ PCN-Drive 3 -------
R
---- SRT ----
R
------- HLT -------
R
ND
------- SC/EOT -------
R
LOCK
R
0
R
--- HUT ---
0
D3
EIS EFIFO
D2
POLL
D1
D0
GAP
-------- PRETRK --------
53
WGATE
-- FIFOTHR --
REMARKS
*Note:
Registers
placed in
FIFO
READ ID
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
W
0
MFM
0
0
1
0
1
0
W
0
0
0
0
0
HDS
DS1
DS0
Execution
Result
R
-------- ST0 --------------- ST1 --------
R
-------- ST2 --------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
54
REMARKS
Commands
The first correct ID
information on the
Cylinder is stored in
Data Register
Status information after
Command execution.
Disk status after the
Command has
completed
PERPENDICULAR MODE
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
D2
D1
D0
REMARKS
W
0
0
0
1
0
0
1
0
OW
0
D3
D2
D1
D0
GAP
WGATE
Command Codes
INVALID CODES
DATA BUS
PHASE
R/W
D7
D6
D5
D4
D3
D2
D1
Command
W
----- Invalid Codes -----
Result
R
------- ST0 -------
REMARKS
D0
Invalid Command Codes
(NoOp - FDC goes into
Standby State)
ST0 = 80H
LOCK
DATA BUS
PHASE
R/W
D7
D6
D5
Command
W
LOCK
0
0
1
0
1
0
0
Result
R
0
0
0
LOCK
0
0
0
0
D4
D3
D2
D1
D0
REMARKS
Command Codes
SC is returned if the last command that was issued was the Format command. EOT is returned if the
last command was a Read or Write.
NOTE: These bits are used internally only. They are not reflected in the Drive Select pins. It is the
user's responsibility to maintain correspondence between these bits and the Drive Select pins (DOR).
55
CRC bytes, and at the end of the sector,
terminate the Read Data Command.
DATA TRANSFER COMMANDS
All of the Read Data, Write Data and Verify type
commands use the same parameter bytes and
return the same results information, the only
difference being the coding of bits 0-4 in the first
byte.
N determines the number of bytes per sector
(see Table 21 below). If N is set to zero, the
sector size is set to 128. The DTL value
determines the number of bytes to be
transferred. If DTL is less than 128, the FDC
transfers the specified number of bytes to the
host. For reads, it continues to read the entire
128-byte sector and checks for CRC errors. For
writes, it completes the 128-byte sector by filling
in zeros. If N is not set to 00 Hex, DTL should
be set to FF Hex and has no impact on the
number of bytes transferred.
An implied seek will be executed if the feature
was enabled by the Configure command. This
seek is completely transparent to the user. The
Drive Busy bit for the drive will go active in the
Main Status Register during the seek portion of
the command. If the seek portion fails, it is
reflected in the results status normally returned
for a Read/Write Data command. Status
Register 0 (ST0) would contain the error code
and C would contain the cylinder on which the
seek failed.
Table 21 - Sector Sizes
Read Data
A set of nine (9) bytes is required to place the
FDC in the Read Data Mode. After the Read
Data command has been issued, the FDC loads
the head (if it is in the unloaded state), waits the
specified head settling time (defined in the
Specify command), and begins reading ID
Address Marks and ID fields. When the sector
address read off the diskette matches with the
sector address specified in the command, the
FDC reads the sector's data field and transfers
the data to the FIFO.
N
SECTOR SIZE
00
01
02
03
..
07
128 bytes
256 bytes
512 bytes
1024 bytes
...
16 Kbytes
The amount of data which can be handled with
a single command to the FDC depends upon
MT (multi-track) and N (number of bytes/sector).
The Multi-Track function (MT) allows the FDC to
read data from both sides of the diskette. For a
particular cylinder, data will be transferred
starting at Sector 1, Side 0 and completing the
last sector of the same track at Side 1.
After completion of the read operation from the
current sector, the sector address is
incremented by one and the data from the next
logical sector is read and output via the FIFO.
This continuous read function is called "MultiSector Read Operation". Upon receipt of TC, or
an implied TC (FIFO overrun/underrun), the
FDC stops sending data but will continue to
read data from the current sector, check the
If the host terminates a read or write operation
in the FDC, the ID information in the result
phase is dependent upon the state of the MT bit
and EOT byte. Refer to Table 22.
56
the Read Data Command.
At the completion of the Read Data command,
the head is not unloaded until after the Head
Unload Time Interval (specified in the Specify
command) has elapsed. If the host issues
another command before the head unloads,
then the head settling time may be saved
between subsequent reads.
After reading the ID and Data Fields in each
sector, the FDC checks the CRC bytes. If a
CRC error occurs in the ID or data field, the
FDC sets the IC code in Status Register 0 to
"01" indicating abnormal termination, sets the
DE bit flag in Status Register 1 to "1", sets the
DD bit in Status Register 2 to "1" if CRC is
incorrect in the ID field, and terminates the Read
Data Command. Table 23 describes the effect
of the SK bit on the Read Data command
execution and results. Except where noted in
Table 23, the C or R value of the sector address
is automatically incremented (see Table 25).
If the FDC detects a pulse on the nINDEX pin
twice without finding the specified sector
(meaning that the diskette's index hole passes
through index detect logic in the drive twice), the
FDC sets the IC code in Status Register 0 to
"01" indicating abnormal termination, sets the
ND bit in Status Register 1 to "1" indicating a
sector
not
found,
and
terminates
MT
0
1
0
1
0
1
N
1
1
2
2
3
3
Table 22 - Effects of MT and N Bits
FINAL SECTOR READ
MAXIMUM TRANSFER
FROM DISK
CAPACITY
256 x 26 = 6,656
26 at side 0 or 1
256 x 52 = 13,312
26 at side 1
512 x 15 = 7,680
15 at side 0 or 1
512 x 30 = 15,360
15 at side 1
1024 x 8 = 8,192
8 at side 0 or 1
1024 x 16 = 16,384
16 at side 1
0
Table 23 - Skip Bit vs Read Data Command
DATA ADDRESS
MARK TYPE
RESULTS
ENCOUNTERED
SECTOR CM BIT OF
DESCRIPTION OF
READ?
ST2 SET?
RESULTS
Normal Data
Yes
No
Normal termination.
0
Deleted Data
Yes
Yes
1
Normal Data
Yes
No
1
Deleted Data
No
Yes
SK BIT
VALUE
Address not incremented.
Next sector not searched for.
Normal termination.
57
Normal termination. Sector
not read ("skipped").
Table 24 describes the effect of the SK bit on
the Read Deleted Data command execution
and results.
Read Deleted Data
This command is the same as the Read Data
command, only it operates on sectors that
contain a Deleted Data Address Mark at the
beginning of a Data Field.
SK BIT
VALUE
0
0
1
1
Except where noted in Table 24, the C or R
value of the sector address is automatically
incremented (see Table 25).
Table 24 - Skip Bit vs. Read Deleted Data Command
DATA ADDRESS
MARK TYPE
RESULTS
ENCOUNTERED
SECTOR CM BIT OF
DESCRIPTION
READ?
ST2 SET?
OF RESULTS
Normal Data
Yes
Yes
Address not
incremented.
Next sector not
searched for.
Normal
Deleted Data
Yes
No
termination.
Normal
Normal Data
No
Yes
termination.
Sector not read
("skipped").
Normal
Deleted Data
Yes
No
termination.
command and sets the ND flag of Status
Register 1 to a "1" if there is no comparison.
Multi-track or skip operations are not allowed
with this command. The MT and SK bits (bits
D7 and D5 of the first command byte
respectively) should always be set to "0".
Read A Track
This command is similar to the Read Data
command except that the entire data field is
read continuously from each of the sectors of
a track. Immediately after encountering a
pulse on the nINDEX pin, the FDC starts to
read all data fields on the track as continuous
blocks of data without regard to logical sector
numbers. If the FDC finds an error in the ID or
DATA CRC check bytes, it continues to read
data from the track and sets the appropriate
error bits at the end of the command. The
FDC compares the ID information read from
each sector with the specified value in the
This command terminates when the EOT
specified number of sectors has not been
read. If the FDC does not find an ID Address
Mark on the diskette after the second
occurrence of a pulse on the IDX pin, then it
sets the IC code in Status Register 0 to "01"
(abnormal termination), sets the MA bit in
Status Register 1 to "1", and terminates the
command.
58
MT
HEAD
0
0
1
1
0
1
Table 25 - Result Phase Table
FINAL SECTOR
ID INFORMATION AT RESULT PHASE
TRANSFERRED TO
HOST
C
H
R
N
Less than EOT
NC
NC
R+1
NC
Equal to EOT
C+1
NC
01
NC
Less than EOT
NC
NC
R+1
NC
Equal to EOT
C+1
NC
01
NC
Less than EOT
NC
NC
R+1
NC
Equal to EOT
NC
LSB
01
NC
Less than EOT
NC
NC
R+1
NC
Equal to EOT
C+1
LSB
01
NC
NC: No Change, the same value as the one at the beginning of command execution.
LSB: Least Significant Bit, the LSB of H is complemented.
sector and checks the CRC bytes. If it detects
a CRC error in one of the ID fields, it sets the
IC code in Status Register 0 to "01" (abnormal
termination), sets the DE bit of Status Register 1
to "1", and terminates the Write Data command.
Write Data
After the Write Data command has been issued,
the FDC loads the head (if it is in the unloaded
state), waits the specified head load time if
unloaded (defined in the Specify command),
and begins reading ID fields. When the sector
address read from the diskette matches the
sector address specified in the command, the
FDC reads the data from the host via the FIFO
and writes it to the sector's data field.
The Write Data command operates in much the
same manner as the Read Data command. The
following items are the same. Please refer to the
Read Data Command for details:
•
Transfer Capacity
•
EN (End of Cylinder) bit
•
ND (No Data) bit
•
Head Load, Unload Time Interval
•
ID information when the host terminates the
command
•
Definition of DTL when N = 0 and when N
does not = 0
After writing data into the current sector, the
FDC computes the CRC value and writes it into
the CRC field at the end of the sector transfer.
The Sector Number stored in "R" is incremented
by one, and the FDC continues writing to the
next data field. The FDC continues this "MultiSector Write Operation". Upon receipt of a
terminal count signal or if a FIFO over/under run
occurs while a data field is being written, then
the remainder of the data field is filled with
zeros.
The FDC reads the ID field of each
Write Deleted Data
This command is almost the same as the Write
Data command except that a Deleted Data
Address Mark is written at the beginning of the
Data Field instead of the normal Data Address
Mark. This command is typically used to mark
59
decremented to 0 (an SC value of 0 will verify
256 sectors). This command can also be
terminated by setting the EC bit to "0" and the
EOT value equal to the final sector to be
checked. If EC is set to "0", DTL/SC should be
programmed to 0FFH. Refer to Table 25 and
Table 26 for information concerning the values
of MT and EC versus SC and EOT value.
a bad sector containing an error on the floppy
disk.
Verify
The Verify command is used to verify the data
stored on a disk. This command acts exactly
like a Read Data command except that no data
is transferred to the host. Data is read from the
disk and CRC is computed and checked against
the previously-stored value.
Definitions:
# Sectors Per Side = Number of formatted
sectors per each side of the disk.
Because data is not transferred to the host, TC
(pin 89) cannot be used to terminate this
command. By setting the EC bit to "1", an
implicit TC will be issued to the FDC. This
implicit TC will occur when the SC value has
# Sectors Remaining = Number of formatted
sectors left which can be read, including side 1
of the disk if MT is set to "1".
Table 26 - Verify Command Result Phase Table
SC/EOT VALUE
TERMINATION RESULT
MT
EC
0
0
SC = DTL
EOT ≤ # Sectors Per Side
Success Termination
Result Phase Valid
0
0
SC = DTL
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
0
1
SC ≤ # Sectors Remaining AND
EOT ≤ # Sectors Per Side
Successful Termination
Result Phase Valid
0
1
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
1
0
SC = DTL
EOT ≤ # Sectors Per Side
Successful Termination
Result Phase Valid
1
0
SC = DTL
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
1
1
SC ≤ # Sectors Remaining AND
EOT ≤ # Sectors Per Side
Successful Termination
Result Phase Valid
1
1
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
Note: If MT is set to "1" and the SC value is greater than the number of remaining formatted sectors
on Side 0, verifying will continue on Side 1 of the disk.
60
After formatting each sector, the host must send
new values for C, H, R and N to the FDC for the
next sector on the track. The R value (sector
number) is the only value that must be changed
by the host after each sector is formatted. This
allows the disk to be formatted with
nonsequential sector addresses (interleaving).
This incrementing and formatting continues for
the whole track until the FDC encounters a pulse
on the IDX pin again and it terminates the
command.
Format A Track
The Format command allows an entire track to
be formatted. After a pulse from the IDX pin is
detected, the FDC starts writing data on the disk
including gaps, address marks, ID fields, and
data fields per the IBM System 34 or 3740
format (MFM or FM respectively). The particular
values that will be written to the gap and data
field are controlled by the values programmed
into N, SC, GPL, and D which are specified by
the host during the command phase. The data
field of the sector is filled with the data byte
specified by D. The ID field for each sector is
supplied by the host; that is, four data bytes per
sector are needed by the FDC for C, H, R, and
N (cylinder, head, sector number and sector size
respectively).
Table 27 contains typical values for gap fields
which are dependent upon the size of the sector
and the number of sectors on each track.
Actual values can vary due to drive electronics.
FORMAT FIELDS
SYSTEM 34 (DOUBLE DENSITY) FORMAT
GAP4a
80x
4E
SYNC
12x
00
IAM
GAP1 SYNC
50x
12x
4E
00
3x FC
C2
IDAM
C
Y
L
H
D
S
E
C
N
O
C
R
C
GAP2 SYNC
22x
12x
4E
00
3x FE
A1
DATA
AM
DATA
C
R
C
GAP3 GAP 4b
DATA
C
R
C
GAP3 GAP 4b
DATA
C
R
C
GAP3 GAP 4b
3x FB
A1 F8
SYSTEM 3740 (SINGLE DENSITY) FORMAT
GAP4a
40x
FF
SYNC
6x
00
IAM
GAP1 SYNC
26x
6x
FF
00
FC
IDAM
C
Y
L
H
D
S
E
C
N
O
C
R
C
GAP2 SYNC
11x
6x
FF
00
FE
DATA
AM
FB or
F8
PERPENDICULAR FORMAT
GAP4a
80x
4E
SYNC
12x
00
IAM
3x FC
C2
GAP1 SYNC
50x
12x
4E
00
IDAM
C
Y
L
H
D
S
E
C
3x FE
A1
N
O
C
R
C
GAP2 SYNC
41x
12x
4E
00
DATA
AM
3x FB
A1 F8
61
FORMAT
GPL2
FM
128
128
512
1024
2048
4096
...
00
00
02
03
04
05
...
12
10
08
04
02
01
07
10
18
46
C8
C8
09
19
30
87
FF
FF
MFM
256
256
512*
1024
2048
4096
...
01
01
02
03
04
05
...
12
10
09
04
02
01
0A
20
2A
80
C8
C8
0C
32
50
F0
FF
FF
FM
128
256
512
0
1
2
0F
09
05
07
0F
1B
1B
2A
3A
MFM
256
512**
1024
1
2
3
0F
09
05
0E
1B
35
36
54
74
5.25"
Drives
3.5"
Drives
Table 27 - Typical Values for Formatting
SECTOR SIZE
N
SC
GPL1
GPL1 = suggested GPL values in Read and Write commands to avoid splice point
between data field and ID field of contiguous sections.
GPL2 = suggested GPL value in Format A Track command.
*PC/AT values (typical)
**PS/2 values (typical). Applies with 1.0 MB and 2.0 MB drives.
NOTE: All values except sector size are in hex.
62
Disks capable of handling more than 80 tracks
per side may require more than one Recalibrate
command to return the head back to physical
Track 0.
CONTROL COMMANDS
Control commands differ from the other
commands in that no data transfer takes place.
Three commands generate an interrupt when
complete: Read ID, Recalibrate, and Seek. The
other control commands do not generate an
interrupt.
The Recalibrate command does not have a
result phase.
The Sense Interrupt Status
command must be issued after the Recalibrate
command to effectively terminate it and to
provide verification of the head position (PCN).
During the command phase of the recalibrate
operation, the FDC is in the BUSY state, but
during the execution phase it is in a NON-BUSY
state.
At this time, another Recalibrate
command may be issued, and in this manner
parallel Recalibrate operations may be done on
up to four drives at once.
Read ID
The Read ID command is used to find the
present position of the recording heads. The
FDC stores the values from the first ID field it is
able to read into its registers. If the FDC does
not find an ID address mark on the diskette after
the second occurrence of a pulse on the
nINDEX pin, it then sets the IC code in Status
Register 0 to "01" (abnormal termination), sets
the MA bit in Status Register 1 to "1", and
terminates the command.
Upon power up, the software must issue a
Recalibrate command to properly initialize all
drives and the controller.
Seek
The following commands will generate an
interrupt upon completion. They do not return
any result bytes. It is highly recommended that
control commands be followed by the Sense
Interrupt Status command. Otherwise, valuable
interrupt status information will be lost.
The read/write head within the drive is moved
from track to track under the control of the Seek
command. The FDC compares the PCN, which
is the current head position, with the NCN and
performs the following operation if there is a
difference:
Recalibrate
PCN < NCN: Direction signal to drive set
to "1" (step in) and issues
step pulses.
PCN > NCN: Direction signal to drive set
to "0" (step out) and issues
step pulses.
This command causes the read/write head
within the FDC to retract to the track 0 position.
The FDC clears the contents of the PCN counter
and checks the status of the nTR0 pin from the
FDD. As long as the nTR0 pin is low, the DIR
pin remains 0 and step pulses are issued.
When the nTR0 pin goes high, the SE bit in
Status Register 0 is set to "1" and the command
is terminated. If the nTR0 pin is still low after 79
step pulses have been issued, the FDC sets the
SE and the EC bits of Status Register 0 to "1"
and terminates the command.
The rate at which step pulses are issued is
controlled by SRT (Stepping Rate Time) in the
Specify command. After each step pulse is
issued, NCN is compared against PCN, and
when NCN = PCN the SE bit in Status Register
0 is set to "1" and the command is terminated.
63
b.
c.
d.
e.
f.
g.
h.
During the command phase of the seek or
recalibrate operation, the FDC is in the BUSY
state, but during the execution phase it is in the
NON-BUSY state. At this time, another Seek or
Recalibrate command may be issued, and in
this manner, parallel seek operations may be
done on up to four drives at once.
Read A Track command
Read ID command
Read Deleted Data command
Write Data command
Format A Track command
Write Deleted Data command
Verify command
Note that if implied seek is not enabled, the read
and write commands should be preceded by:
2. End of Seek, Relative Seek, or Recalibrate
command
1) Seek command - Step to the proper track
2) Sense Interrupt Status command
Terminate the Seek command
3) Read ID - Verify head is on proper track
4) Issue Read/Write command.
3. FDC requires a data transfer during the
execution phase in the non-DMA mode
-
The Sense Interrupt Status command resets the
interrupt signal and, via the IC code and SE bit
of Status Register 0, identifies the cause of the
interrupt.
The Seek command does not have a result
phase. Therefore, it is highly recommended that
the Sense Interrupt Status command be issued
after the Seek command to terminate it and to
provide verification of the head position (PCN).
The H bit (Head Address) in ST0 will always
return to a "0". When exiting POWERDOWN
mode, the FDC clears the PCN value and the
status information to zero. Prior to issuing the
POWERDOWN command, it is highly
recommended that the user service all pending
interrupts through the Sense Interrupt Status
command.
Table 28 - Interrupt Identification
SE
IC
INTERRUPT DUE TO
0
1
11
00
1
01
Polling
Normal termination of Seek
or Recalibrate command
Abnormal termination of
Seek or Recalibrate
command
The Seek, Relative Seek, and Recalibrate
commands have no result phase. The Sense
Interrupt Status command must be issued
immediately after these commands to terminate
them and to provide verification of the head
position (PCN). The H (Head Address) bit in
ST0 will always return a "0". If a Sense Interrupt
Status is not issued, the drive will continue to be
BUSY and may affect the operation of the next
command.
Sense Interrupt Status
An interrupt signal on FINT pin is generated by
the FDC for one of the following reasons:
1. Upon entering the Result Phase of:
a. Read Data command
64
from the end of the execution phase of one of
the read/write commands to the head unload
state. The SRT (Step Rate Time) defines the
time interval between adjacent step pulses. Note
that the spacing between the first and second
step pulses may be shorter than the remaining
step pulses.
The HLT (Head Load Time)
defines the time between when the Head Load
signal goes high and the read/write operation
starts. The values change with the data rate
speedselection and are documented in Table 29.
The values are the same for MFM and FM.
Sense Drive Status
Sense Drive Status obtains drive status
information. It has no execution phase and
goes directly to the result phase from the
command phase. Status Register 3 contains
the drive status information.
Specify
The Specify command sets the initial values for
each of the three internal times. The HUT
(Head Unload Time) defines the time
Table 29 - Drive Control Delays (ms)
HUT
SRT
0
1
..
E
F
2M
1M
500K
300K
250K
2M
1M
500K
300K
250K
64
4
..
56
60
128
8
..
112
120
256
16
..
224
240
426
26.7
..
373
400
512
32
..
448
480
4
3.75
..
0.5
0.25
8
7.5
..
1
0.5
16
15
..
2
1
26.7
25
..
3.33
1.67
32
30
..
4
2
HLT
00
01
02
..
7F
7F
2M
1M
500K
300K
250K
64
0.5
1
..
63
63.5
128
1
2
..
126
127
256
2
4
..
252
254
426
3.3
6.7
..
420
423
512
4
8
.
504
508
The choice of DMA or non-DMA operations is
made by the ND bit. When this bit is "1", the
non-DMA mode is selected, and when ND is "0",
the DMA mode is selected. In DMA mode, data
transfers are signalled by the FDRQ pin. NonDMA mode uses the RQM bit and the FINT pin
to signal data transfers.
Configure
The Configure command is issued to select the
special features of the FDC.
A Configure
command need not be issued if the default
values of the FDC meet the system
requirements.
65
Configure Default Values:
Relative Seek
EIS - No Implied Seeks
EFIFO - FIFO Disabled
POLL - Polling Enabled
FIFOTHR - FIFO Threshold Set to 1 Byte
PRETRK - Pre-Compensation Set to Track 0
The command is coded the same as for Seek,
except for the MSB of the first byte and the DIR
bit.
DIR
EIS - Enable Implied Seek. When set to "1", the
FDC will perform a Seek operation before
executing a read or write command. Defaults to
no implied seek.
Head Step Direction Control
DIR
0
1
EFIFO - A "1" disables the FIFO (default). This
means data transfers are asked for on a byteby-byte basis. Defaults to "1", FIFO disabled.
The threshold defaults to "1".
RCN
POLL - Disable polling of the drives. Defaults to
"0", polling enabled. When enabled, a single
interrupt is generated after a reset. No polling is
performed while the drive head is loaded and
the head unload delay has not expired.
ACTION
Step Head Out
Step Head In
Relative
Cylinder
Number
that
determines how many tracks to step the
head in or out from the current track
number.
The Relative Seek command differs from the
Seek command in that it steps the head the
absolute number of tracks specified in the
command instead of making a comparison
against an internal register.
The Seek
command is good for drives that support a
maximum of 256 tracks. Relative Seeks cannot
be overlapped with other Relative Seeks. Only
one Relative Seek can be active at a time.
Relative Seeks may be overlapped with Seeks
and Recalibrates. Bit 4 of Status Register 0
(EC) will be set if Relative Seek attempts to step
outward beyond Track 0.
FIFOTHR - The FIFO threshold in the execution
phase of read or write commands. This is
programmable from 1 to 16 bytes. Defaults to
one byte. A "00" selects one byte; "0F" selects
16 bytes.
PRETRK - Pre-Compensation Start Track
Number. Programmable from track 0 to 255.
Defaults to track 0. A "00" selects track 0; "FF"
selects track 255.
As an example, assume that a floppy drive has
300 useable tracks. The host needs to read
track 300 and the head is on any track (0-255).
If a Seek command is issued, the head will stop
at track 255. If a Relative Seek command is
issued, the FDC will move the head the
specified number of tracks, regardless of the
internal cylinder position register (but will
increment the register). If the head was on track
40 (d), the maximum track that the FDC could
position the head on using Relative Seek will be
295 (D), the initial track + 255 (D). The
maximum count that the head can be moved
Version
The Version command checks to see if the
controller is an enhanced type or the older type
(765A). A value of 90 H is returned as the result
byte.
66
with a single Relative Seek command is 255
(D).
to keep track of with software without the Read
ID command.
The internal register, PCN, will overflow as the
cylinder number crosses track 255 and will
contain 39 (D). The resulting PCN value is thus
(RCN + PCN) mod 256. Functionally, the FDC
starts counting from 0 again as the track
number goes above 255 (D). It is the user's
responsibility to compensate FDC functions
(precompensation
track
number)
when
accessing tracks greater than 255. The FDC
does not keep track that it is working in an
"extended track area" (greater than 255). Any
command issued will use the current PCN value
except for the Recalibrate command, which only
looks for the TRACK0 signal. Recalibrate will
return an error if the head is farther than 79 due
to its limitation of issuing a maximum of 80 step
pulses. The user simply needs to issue a
second Recalibrate command.
The Seek
command and implied seeks will function
correctly within the 44 (D) track (299-255) area
of the "extended track area". It is the user's
responsibility not to issue a new track position
that will exceed the maximum track that is
present in the extended area.
Perpendicular Mode
The Perpendicular Mode command should be
issued prior to executing Read/Write/Format
commands that access a disk drive with
perpendicular recording capability. With this
command, the length of the Gap2 field and VCO
enable timing can be altered to accommodate
the unique requirements of these drives. Table
30 describes the effects of the WGATE and
GAP bits for the Perpendicular Mode command.
Upon a reset, the FDC will default to the
conventional mode (WGATE = 0, GAP = 0).
Selection of the 500 Kbps and 1 Mbps
perpendicular modes is independent of the
actual data rate selected in the Data Rate Select
Register. The user must ensure that these two
data rates remain consistent.
The Gap2 and VCO timing requirements for
perpendicular recording type drives are dictated
by the design of the read/write head. In the
design of this head, a pre-erase head precedes
the normal read/write head by a distance of 200
micrometers. This works out to about 38 bytes
at a 1 Mbps recording density. Whenever the
write head is enabled by the Write Gate signal,
the pre-erase head is also activated at the same
time. Thus, when the write head is initially
turned on, flux transitions recorded on the media
for the first 38 bytes will not be preconditioned
with the pre-erase head since it has not yet been
activated. To accommodate this head activation
and deactivation time, the Gap2 field is
expanded to a length of 41 bytes. The format
field shown on Page 61 illustrates the change in
the Gap2 field size for the perpendicular format.
To return to the standard floppy range (0-255) of
tracks, a Relative Seek should be issued to
cross the track 255 boundary.
A Relative Seek can be used instead of the
normal Seek, but the host is required to
calculate the difference between the current
head location and the new (target) head
location. This may require the host to issue a
Read ID command to ensure that the head is
physically on the track that software assumes it
to be. Different FDC commands will return
different cylinder results which may be difficult
67
enhancement allows data transfers between
Conventional and Perpendicular drives without
having to issue Perpendicular mode commands
between the accesses of the different drive
types, nor having to change write precompensation values.
On the read back by the FDC, the controller
must begin synchronization at the beginning of
the sync field. For the conventional mode, the
internal PLL VCO is enabled (VCOEN)
approximately 24 bytes from the start of the
Gap2 field. But, when the controller operates in
the 1 Mbps perpendicular mode (WGATE = 1,
GAP = 1), VCOEN goes active after 43 bytes to
accommodate the increased Gap2 field size.
For both cases, and approximate two-byte
cushion is maintained from the beginning of the
sync field for the purposes of avoiding write
splices in the presence of motor speed variation.
When both GAP and WGATE bits of the
PERPENDICULAR MODE COMMAND are both
programmed to "0" (Conventional mode), then
D0, D1, D2, D3, and D4 can be programmed
independently to "1" for that drive to be set
automatically to Perpendicular mode. In this
mode the following set of conditions also apply:
For the Write Data case, the FDC activates
Write Gate at the beginning of the sync field
under the conventional mode. The controller
then writes a new sync field, data address mark,
data field, and CRC as shown on page 62. With
the pre-erase head of the perpendicular drive,
the write head must be activated in the Gap2
field to insure a proper write of the new sync
field. For the 1 Mbps perpendicular mode
(WGATE = 1, GAP = 1), 38 bytes will be written
in the Gap2 space. Since the bit density is
proportional to the data rate, 19 bytes will be
written in the Gap2 field for the 500 Kbps
perpendicular mode (WGATE = 1, GAP =0).
1. The GAP2 written to a perpendicular drive
during a write operation will depend upon the
programmed data rate.
2. The write pre-compensation given to a
perpendicular mode drive will be 0ns.
3. For D0-D3 programmed to "0" for
conventional mode drives any data written
will be at the currently programmed write
pre-compensation.
Note: Bits D0-D3 can only be overwritten when
OW is programmed as a "1".If either
GAP or WGATE is a "1" then D0-D3 are
ignored.
It should be noted that none of the alterations in
Gap2 size, VCO timing, or Write Gate timing
affect normal program flow. The information
provided here is just for background purposes
and is not needed for normal operation. Once
the Perpendicular Mode command is invoked,
FDC software behavior from the user standpoint
is unchanged.
Software and hardware
following effect on the
MODE COMMAND:
resets have the
PERPENDICULAR
1. "Software" resets (via the DOR or DSR
registers) will only clear GAP and WGATE
bits to "0". D0-D3 are unaffected and retain
their previous value.
2. "Hardware" resets will clear all bits (GAP,
WGATE and D0-D3) to "0", i.e all
conventional mode.
The perpendicular mode command is enhanced
to allow specific drives to be designated
Perpendicular
recording
drives. This
68
WGATE
Table 30 - Effects of WGATE and GAP Bits
PORTION OF
GAP 2
WRITTEN BY
LENGTH OF
GAP2 FORMAT WRITE DATA
OPERATION
FIELD
MODE
GAP
0
0
0
1
1
0
1
1
Conventional
Perpendicular
(500 Kbps)
Reserved
(Conventional)
Perpendicular
(1 Mbps)
22 Bytes
22 Bytes
0 Bytes
19 Bytes
22 Bytes
0 Bytes
41 Bytes
38 Bytes
LOCK
ENHANCED DUMPREG
In order to protect systems with long DMA
latencies against older application software that
can disable the FIFO, the LOCK Command has
been added. This command should only be
used by the FDC routines, and application
software should refrain from using it. If an
application calls for the FIFO to be disabled
then the CONFIGURE command should be
used.
The DUMPREG command is designed to
support system run-time diagnostics and
application software development and debug.
To accommodate the LOCK command and the
enhanced PERPENDICULAR MODE command
the eighth byte of the DUMPREG command has
been modified to contain the additional data
from these two commands.
COMPATIBILITY
The LOCK command defines whether the
EFIFO, FIFOTHR, and PRETRK parameters of
the CONFIGURE command can be RESET by
the DOR and DSR registers. When the LOCK
bit is set to logic "1" all subsequent "software
RESETS by the DOR and DSR registers will not
change the previously set parameters to their
default values. All "hardware" RESET from the
RESET pin will set the LOCK bit to logic "0" and
return the EFIFO, FIFOTHR, and PRETRK to
their default values. A status byte is returned
immediately after issuing a a LOCK command.
This byte reflects the value of the LOCK bit set
by the command byte.
The FDC37C93xAPM was designed with
software compatibility in mind. It is a fully
backwards-compatible solution with the older
generation 765A/B disk controllers. The FDC
also implements on-board registers for
compatibility with the PS/2, as well as PC/AT
and PC/XT, floppy disk controller subsystems.
After a hardware reset of the FDC, all registers,
functions and enhancements default to a PC/AT,
PS/2 or PS/2 Model 30 compatible operating
mode, depending on how the IDENT and MFM
bits are configured by the system BIOS.
69
SERIAL PORT (UART)
by programming OUT2 of that UART to a logic
"1". OUT2 being a logic "0" disables that
UART's interrupt.
The second UART also
supports IrDA, HP-SIR and ASK-IR infrared
modes of operation.
The FDC37C93xAPM incorporates two full
function UARTs. They are compatible with the
NS16450, the 16450 ACE registers and the
NS16550A.
The UARTS perform serial-toparallel conversion on received characters and
parallel-to-serial
conversion
on
transmit
characters. The data rates are independently
programmable from 460.8K baud down to 50
baud. The character options are programmable
for 1 start; 1, 1.5 or 2 stop bits; even, odd, sticky
or no parity; and prioritized interrupts. The
UARTs each contain a programmable baud rate
generator that is capable of dividing the input
clock or crystal by a number from 1 to 65535.
The UARTs are also capable of supporting the
MIDI data rate. Refer to the Configuration
Registers for information on disabling, power
down and changing the base address of the
UARTs. The interrupt from a UART is enabled
Note: The UARTs may be configured to share
an interrupt. Refer to the Configuration section
for more information.
REGISTER DESCRIPTION
Addressing of the accessible registers of the
Serial Port is shown below.
The base
addresses of the serial ports are defined by the
configuration registers (see Configuration
section). The Serial Port registers are located at
sequentially increasing addresses above these
base addresses. The FDC37C93xAPM contains
two serial ports, each of which contain a register
set as described below.
Table 31 - Addressing the Serial Port
A1
A0
REGISTER NAME
DLAB*
A2
0
0
0
0
Receive Buffer (read)
0
0
0
0
Transmit Buffer (write)
0
0
0
1
Interrupt Enable (read/write)
X
0
1
0
Interrupt Identification (read)
X
0
1
0
FIFO Control (write)
X
0
1
1
Line Control (read/write)
X
1
0
0
Modem Control (read/write)
X
1
0
1
Line Status (read/write)
X
1
1
0
Modem Status (read/write)
X
1
1
1
Scratchpad (read/write)
1
0
0
0
Divisor LSB (read/write)
1
0
0
1
Divisor MSB (read/write)
*Note: DLAB is Bit 7 of the Line Control Register
70
The following section describes the operation of
the registers.
BIT 0
This bit enables the Received Data Available
Interrupt (and timeout interrupts in the FIFO
mode) when set to logic "1".
RECEIVE BUFFER REGISTER (RB)
Address Offset = 0H, DLAB = 0, READ ONLY
BIT 1
This bit enables the Transmitter Holding
Register Empty Interrupt when set to logic "1".
This register holds the received incoming data
byte. Bit 0 is the least significant bit, which is
transmitted and received first. Received data is
double buffered; this uses an additional shift
register to receive the serial data stream and
convert it to a parallel 8 bit word which is
transferred to the Receive Buffer register. The
shift register is not accessible.
BIT 2
This bit enables the Received Line Status
Interrupt when set to logic "1". The error
sources causing the interrupt are Overrun,
Parity, Framing and Break. The Line Status
Register must be read to determine the source.
TRANSMIT BUFFER REGISTER (TB)
Address Offset = 0H, DLAB = 0, WRITE ONLY
BIT 3
This bit enables the MODEM Status Interrupt
when set to logic "1". This is caused when one
of the Modem Status Register bits changes
state.
This register contains the data byte to be
transmitted.
The transmit buffer is double
buffered, utilizing an additional shift register (not
accessible) to convert the 8 bit data word to a
serial format. This shift register is loaded from
the Transmit Buffer when the transmission of
the previous byte is complete.
BIT 4 - 7
These bits are always logic "0".
FIFO CONTROL REGISTER (FCR)
Address Offset = 2H, DLAB = X, WRITE
INTERRUPT ENABLE REGISTER (IER)
Address Offset = 1H, DLAB = 0, READ/WRITE
This is a write only register at the same location
as the IIR. This register is used to enable and
clear the FIFOs, set the RCVR FIFO trigger
level. Note: DMA is not supported.
The lower four bits of this register control the
enables of the five interrupt sources of the Serial
Port interrupt. It is possible to totally disable the
interrupt system by resetting bits 0 through 3 of
this register. Similarly, setting the appropriate
bits of this register to a high, selected interrupts
can be enabled. Disabling the interrupt system
inhibits the Interrupt Identification Register and
disables any Serial Port interrupt out of the
FDC37C93xAPM. All other system functions
operate in their normal manner, including the
Line Status and MODEM Status Registers. The
contents of the Interrupt Enable Register are
described below.
BIT 0
Setting this bit to a logic "1" enables both the
XMIT and RCVR FIFOs. Clearing this bit to a
logic "0" disables both the XMIT and RCVR
FIFOs and clears all bytes from both FIFOs.
When changing from FIFO Mode to non-FIFO
(16450) mode, data is automatically cleared
from the FIFOs. This bit must be a 1 when
other bits in this register are written to or they
will not be properly programmed.
71
1.
2.
3.
4.
BIT 1
Setting this bit to a logic "1" clears all bytes in
the RCVR FIFO and resets its counter logic to 0.
The shift register is not cleared. This bit is selfclearing.
Information indicating that a prioritized interrupt
is pending and the source of that interrupt is
stored in the Interrupt Identification Register
(refer to Interrupt Control Table). When the CPU
accesses the IIR, the Serial Port freezes all
interrupts and indicates the highest priority
pending interrupt to the CPU. During this CPU
access, even if the Serial Port records new
interrupts, the current indication does not
change until access is completed. The contents
of the IIR are described below.
BIT 2
Setting this bit to a logic "1" clears all bytes in
the XMIT FIFO and resets its counter logic to 0.
The shift register is not cleared. This bit is selfclearing.
BIT 3
Writting to this bit has no effect on the operation
of the UART. The RXRDY and TXRDY pins are
not available on this chip.
BIT 0
This bit can be used in either a hardwired
prioritized or polled environment to indicate
whether an interrupt is pending. When bit 0 is a
logic "0", an interrupt is pending and the
contents of the IIR may be used as a pointer to
the appropriate internal service routine. When
bit 0 is a logic "1", no interrupt is pending.
BIT 4 and 5
Reserved
BIT 6 and 7
These bits are used to set the trigger level for
the RCVR FIFO interrupt.
INTERRUPT IDENTIFICATION REGISTER
(IIR)
Address Offset = 2H, DLAB = X, READ
Bit 7
0
Bit 6
0
RCVR FIFO
TRIGGER LEVEL (BYTES)
1
0
1
4
1
0
8
1
1
14
Receiver Line Status (highest priority)
Received Data Ready
Transmitter Holding Register Empty
MODEM Status (lowest priority)
BIT 1 and 2
These two bits of the IIR are used to identify the
highest priority interrupt pending as indicated by
the Interrupt Control Table.
BIT 3
In non-FIFO mode, this bit is a logic "0". In
FIFO mode this bit is set along with bit 2 when a
timeout interrupt is pending.
BIT 4 and 5
These bits of the IIR are always logic "0".
By accessing this register, the host CPU can
determine the highest priority interrupt and its
source. Four levels of priority interrupt exist.
They are in descending order of priority:
BIT 6 and 7
These two bits are set when the FIFO
CONTROL Register bit 0 equals 1.
72
Table 32 - Interrupt Control Table
FIFO
MODE
ONLY
INTERRUPT
IDENTIFICATION
REGISTER
INTERRUPT SET AND RESET FUNCTIONS
BIT
3
BIT
2
BIT
1
BIT
0
PRIORITY
LEVEL
0
0
0
1
-
0
1
1
0
0
1
0
1
1
0
0
INTERRUPT
TYPE
INTERRUPT
SOURCE
INTERRUPT
RESET CONTROL
None
None
Highest
Receiver Line
Status
Overrun Error,
Parity Error,
Framing Error or
Break Interrupt
Reading the Line
Status Register
0
Second
Received Data
Available
Receiver Data
Available
Read Receiver
Buffer or the FIFO
drops below the
trigger level.
0
0
Second
Character
Timeout
Indication
No Characters
Have Been
Removed From
or Input to the
RCVR FIFO
during the last 4
Char times and
there is at least 1
char in it during
this time
Reading the
Receiver Buffer
Register
0
1
0
Third
Transmitter
Holding Register
Empty
Transmitter
Holding Register
Empty
Reading the IIR
Register (if Source
of Interrupt) or
Writing the
Transmitter Holding
Register
0
0
0
Fourth
MODEM Status
Clear to Send or
Data Set Ready
or Ring Indicator
or Data Carrier
Detect
Reading the
MODEM Status
Register
73
-
BIT 3
Parity Enable bit. When bit 3 is a logic "1", a
parity bit is generated (transmit data) or
checked (receive data) between the last data
word bit and the first stop bit of the serial data.
(The parity bit is used to generate an even or
odd number of 1s when the data word bits and
the parity bit are summed).
LINE CONTROL REGISTER (LCR)
Address Offset = 3H, DLAB = 0, READ/WRITE
This register contains the format information of
the serial line. The bit definitions are:
BIT 0 and 1
These two bits specify the number of bits in
each transmitted or received serial character.
The encoding of bits 0 and 1 is as follows:
BIT 1
0
0
1
1
BIT 4
Even Parity Select bit. When bit 3 is a logic "1"
and bit 4 is a logic "0", an odd number of logic
"1"'s is transmitted or checked in the data word
bits and the parity bit. When bit 3 is a logic "1"
and bit 4 is a logic "1" an even number of bits is
transmitted and checked.
BIT 0 WORD LENGTH
0
1
0
1
5 Bits
6 Bits
7 Bits
8 Bits
BIT 5
Stick Parity bit. When bit 3 is a logic "1" and bit
5 is a logic "1", the parity bit is transmitted and
then detected by the receiver in the opposite
state indicated by bit 4.
The Start, Stop and Parity bits are not included
in the word length.
BIT 6
Set Break Control bit. When bit 6 is a logic "1",
the transmit data output (TXD) is forced to the
Spacing or logic "0" state and remains there
(until reset by a low level bit 6) regardless of
other transmitter activity. This feature enables
the Serial Port to alert a terminal in a
communications system.
BIT 2
This bit specifies the number of stop bits in each
transmitted or received serial character. The
following table summarizes the information.
BIT 2
WORD LENGTH
NUMBER OF
STOP BITS
0
--
1
1
5 bits
1.5
1
6 bits
2
1
7 bits
2
1
8 bits
2
BIT 7
Divisor Latch Access bit (DLAB). It must be set
high (logic "1") to access the Divisor Latches of
the Baud Rate Generator during read or write
operations. It must be set low (logic "0") to
access the Receiver Buffer Register, the
Transmitter Holding Register, or the Interrupt
Enable Register.
Note: The receiver will ignore all stop bits
beyond the first, regardless of the number used
in transmitting.
MODEM CONTROL REGISTER (MCR)
Address Offset = 4H, DLAB =
READ/WRITE
74
X,
5.
This 8 bit register controls the interface with the
MODEM or data set (or device emulating a
MODEM). The contents of the MODEM control
register are described below.
6.
BIT 0
This bit controls the Data Terminal Ready
(nDTR) output. When bit 0 is set to a logic "1",
the nDTR output is forced to a logic "0". When
bit 0 is a logic "0", the nDTR output is forced to
a logic "1".
7.
This feature allows the processor to verify the
transmit and receive data paths of the Serial
Port. In the diagnostic mode, the receiver and
the transmitter interrupts are fully operational.
The MODEM Control Interrupts are also
operational but the interrupts' sources are now
the lower four bits of the MODEM Control
Register instead of the MODEM Control inputs.
The interrupts are still controlled by the Interrupt
Enable Register.
BIT 1
This bit controls the Request To Send (nRTS)
output. Bit 1 affects the nRTS output in a
manner identical to that described above for bit
0.
BIT 2
This bit controls the Output 1 (OUT1) bit. This
bit does not have an output pin and can only be
read or written by the CPU.
BIT 5 - 7
These bits are permanently set to logic “0”.
LINE STATUS REGISTER (LSR)
Address Offset = 5H, DLAB
READ/WRITE
BIT 3
Output 2 (OUT2). This bit is used to enable an
UART interrupt. When OUT2 is a logic "0", the
serial port interrupt output is forced to a high
impedance state - disabled. When OUT2 is a
logic "1", the serial port interrupt outputs are
enabled.
2.
3.
4.
=
X,
BIT 0
Data Ready (DR). It is set to a logic "1"
whenever a complete incoming character has
been received and transferred into the Receiver
Buffer Register or the FIFO. Bit 0 is reset to a
logic "0" by reading all of the data in the Receive
Buffer Register or the FIFO.
BIT 4
This bit provides the loopback feature for
diagnostic testing of the Serial Port. When bit 4
is set to logic "1", the following occur:
1.
The four MODEM Control outputs (nDTR,
nRTS, OUT1 and OUT2) are internally
connected to the four MODEM Control
inputs (nDSR, nCTS, RI, DCD).
The Modem Control output pins are forced
inactive high.
Data that is transmitted is immediately
received.
BIT 1
Overrun Error (OE). Bit 1 indicates that data in
the Receiver Buffer Register was not read before
the next character was transferred into the
register, thereby destroying the previous
character. In FIFO mode, an overrunn error will
occur only when the FIFO is full and the next
character has been completely received in the
shift register, the character in the shift register is
overwritten but not transferred to the FIFO. The
OE indicator is set to a logic "1" immediately
The TXD is set to the Marking State (logic
"1").
The receiver Serial Input (RXD) is
disconnected.
The output of the Transmitter Shift
Register is "looped back" into the Receiver
Shift Register input.
All MODEM Control inputs (nCTS, nDSR,
nRI and nDCD) are disconnected.
75
Restarting after a break is received, requires the
serial data (RXD) to be logic "1" for at least 1/2
bit time.
upon detection of an overrun condition, and
reset whenever the Line Status Register is read.
BIT 2
Parity Error (PE). Bit 2 indicates that the
received data character does not have the
correct even or odd parity, as selected by the
even parity select bit. The PE is set to a logic
"1" upon detection of a parity error and is
reset to a logic "0" whenever the Line Status
Register is read. In the FIFO mode this error is
associated with the particular character in the
FIFO it applies to. This error is indicated when
the associated character is at the top of the
FIFO.
Note: Bits 1 through 4 are the error conditions
that produce a Receiver Line Status Interrupt
whenever any of the corresponding conditions
are detected and the interrupt is enabled.
BIT 5
Transmitter Holding Register Empty (THRE). Bit
5 indicates that the Serial Port is ready to accept
a new character for transmission. In addition,
this bit causes the Serial Port to issue an
interrupt when the Transmitter Holding Register
interrupt enable is set high. The THRE bit is set
to a logic "1" when a character is transferred
from the Transmitter Holding Register into the
Transmitter Shift Register. The bit is reset to
logic "0" whenever the CPU loads the
Transmitter Holding Register. In the FIFO mode
this bit is set when the XMIT FIFO is empty, it is
cleared when at least one byte is written to the
XMIT FIFO. Bit 5 is a read- only bit.
BIT 3
Framing Error (FE). Bit 3 indicates that the
received character did not have a valid stop bit.
Bit 3 is set to a logic "1" whenever the stop bit
following the last data bit or parity bit is detected
as a zero bit (Spacing level). The FE is reset to
a logic "0" whenever the Line Status Register is
read. In the FIFO mode this error is associated
with the particular character in the FIFO it
applies to. This error is indicated when the
associated character is at the top of the FIFO.
The Serial Port will try to resynchronize after a
framing error. To do this, it assumes that the
framing error was due to the next start bit, so it
samples this 'start' bit twice and then takes in
the 'data'.
BIT 6
Transmitter Empty (TEMT). Bit 6 is set to a
logic "1" whenever the Transmitter Holding
Register (THR) and Transmitter Shift Register
(TSR) are both empty. It is reset to logic "0"
whenever either the THR or TSR contains a data
character. Bit 6 is a read only bit. In the FIFO
mode this bit is set whenever the THR and TSR
are both empty.
BIT 4
Break Interrupt (BI). Bit 4 is set to a logic "1"
whenever the received data input is held in the
Spacing state (logic "0") for longer than a full
word transmission time (that is, the total time of
the start bit + data bits + parity bits + stop bits).
The BI is reset after the CPU reads the contents
of the Line Status Register. In the FIFO mode
this error is associated with the particular
character in the FIFO it applies to. This error is
indicated when the associated character is at
the top of the FIFO. When break occurs only
one zero character is loaded into the FIFO.
BIT 7
This bit is permanently set to logic "0" in the 450
mode. In the FIFO mode, this bit is set to a
logic "1" when there is at least one parity error,
framing error or break indication in the FIFO.
This bit is cleared when the LSR is read if there
are no subsequent errors in the FIFO.
76
MODEM STATUS REGISTER (MSR)
Address Offset = 6H, DLAB
READ/WRITE
=
BIT 5
This bit is the complement of the Data Set
Ready (nDSR) input. If bit 4 of the MCR is set
to logic "1", this bit is equivalent to DTR in the
MCR.
X,
This 8 bit register provides the current state of
the control lines from the MODEM (or peripheral
device).
In addition to this current state
information, four bits of the MODEM Status
Register (MSR) provide change information.
These bits are set to logic "1" whenever a
control input from the MODEM changes state.
They are reset to logic "0" whenever the
MODEM Status Register is read.
BIT 6
This bit is the complement of the Ring Indicator
(nRI) input. If bit 4 of the MCR is set to logic
"1", this bit is equivalent to OUT1 in the MCR.
BIT 7
This bit is the complement of the Data Carrier
Detect (nDCD) input. If bit 4 of the MCR is set
to logic "1", this bit is equivalent to OUT2 in the
MCR.
BIT 0
Delta Clear To Send (DCTS). Bit 0 indicates
that the nCTS input to the chip has changed
state since the last time the MSR was read.
SCRATCHPAD REGISTER (SCR)
Address Offset =7H, DLAB =X, READ/WRITE
BIT 1
Delta Data Set Ready (DDSR). Bit 1 indicates
that the nDSR input has changed state since the
last time the MSR was read.
This 8 bit read/write register has no effect on the
operation of the Serial Port. It is intended as a
scratchpad register to be used by the
programmer to hold data temporarily.
BIT 2
Trailing Edge of Ring Indicator (TERI). Bit 2
indicates that the nRI input has changed from
logic "0" to logic "1".
PROGRAMMABLE BAUD RATE GENERATOR
(AND DIVISOR LATCHES DLH, DLL)
The Serial Port contains a programmable Baud
Rate Generator that is capable of taking any
clock input (DC to 3 MHz) and dividing it by any
divisor from 1 to 65535. This output frequency
of the Baud Rate Generator is 16x the Baud
rate. Two 8 bit latches store the divisor in 16 bit
binary format. These Divisor Latches must be
loaded during initialization in order to insure
desired operation of the Baud Rate Generator.
Upon loading either of the Divisor Latches, a 16
bit Baud counter is immediately loaded. This
prevents long counts on initial load. If a 0 is
loaded into the BRG registers the output divides
the clock by the number 3. If a 1 is loaded the
output is the inverse of the input oscillator. If a
two is loaded the output is a divide by 2 signal
with a 50% duty cycle. If a 3 or greater is
loaded the output is low for 2 bits and high for
BIT 3
Delta Data Carrier Detect (DDCD).
Bit 3
indicates that the nDCD input to the chip has
changed state.
NOTE: Whenever bit 0, 1, 2, or 3 is set to a
logic "1", a MODEM Status Interrupt is
generated.
BIT 4
This bit is the complement of the Clear To Send
(nCTS) input. If bit 4 of the MCR is set to logic
"1", this bit is equivalent to nRTS in the MCR.
77
the remainder of the count. The input clock to
the BRG is a 1.8462 MHz clock.
Table 33 shows the baud rates possible with a
1.8462 MHz crystal.
-
Effect Of The Reset on Register File
was longer than four continuous character
times ago. (If two stop bits are
programmed, the second one is included in
this time delay.)
The most recent CPU read of the FIFO was
longer than 4 continuous character times
ago.
The Reset Function Table (Table 34) details the
effect of the Reset input on each of the registers
of the Serial Port.
This will cause a maximum character received
to interrupt issued delay of 160 msec at
300BAUD with a 12 bit character.
FIFO INTERRUPT MODE OPERATION
B. Character times are calculated by using the
RCLK input for a clock signal (this makes
the delay proportional to the baud rate).
When the RCVR FIFO and receiver interrupts
are enabled (FCR bit 0 = "1", IER bit 0 = "1"),
RCVR interrupts occur as follows:
A. The receive data available interrupt will
issued when the FIFO has reached
programmed trigger level; it is cleared
soon as the FIFO drops below
programmed trigger level.
C. When a timeout interrupt has occurred it is
cleared and the timer reset when the CPU
reads one character from the RCVR FIFO.
be
its
as
its
D. When a timeout interrupt has not occurred
the timeout timer is reset after a new
character is received or after the CPU reads
the RCVR FIFO.
B. The IIR receive data available indication also
occurs when the FIFO trigger level is
reached. It is cleared when the FIFO drops
below the trigger level.
When the XMIT FIFO and transmitter interrupts
are enabled (FCR bit 0 = "1", IER bit 1 = "1"),
XMIT interrupts occur as follows:
A. The transmitter holding register interrupt
(02H) occurs when the XMIT FIFO is empty;
it is cleared as soon as the transmitter
holding register is written to (1 of 16
characters may be written to the XMIT FIFO
while servicing this interrupt) or the IIR is
read.
C. The receiver line status interrupt (IIR=06H),
has higher priority than the received data
available (IIR=04H) interrupt.
D. The data ready bit (LSR bit 0) is set as soon
as a character is transferred from the shift
register to the RCVR FIFO. It is reset when
the FIFO is empty.
B. The transmitter FIFO empty indications will
be delayed 1 character time minus the last
stop bit time whenever the following occurs:
THRE=1 and there have not been at least
two bytes at the same time in the transmitter
FIFO since the last THRE=1. The transmitter
interrupt after changing FCR0 will be
immediate, if it is enabled.
When RCVR FIFO and receiver interrupts are
enabled, RCVR FIFO timeout interrupts occur
as follows:
A.
-
A FIFO timeout interrupt occurs if all the
following conditions exist:
at least one character is in the FIFO
The most recent serial character received
78
-
Character timeout and RCVR FIFO trigger level
interrupts have the same priority as the current
received data available interrupt; XMIT FIFO
empty has the same priority as the current
transmitter holding register empty interrupt.
-
FIFO POLLED MODE OPERATION
With FCR bit 0 = "1" resetting IER bits 0, 1, 2 or
3 or all to “0” puts the UART in the FIFO Polled
Mode of operation. Since the RCVR and
XMITTER are controlled separately, either one
or both can be in the polled mode of operation.
-
Bit 0=1 as long as there is one byte in the
RCVR FIFO.
Bits 1 to 4 specify which error(s) have
occurred. Character error status is handled
the same way as when in the interrupt
mode, the IIR is not affected since EIR bit
2=0.
Bit 5 indicates when the XMIT FIFO is
empty.
Bit 6 indicates that both the XMIT FIFO and
shift register are empty.
Bit 7 indicates whether there are any errors
in the RCVR FIFO.
There is no trigger level reached or timeout
condition indicated in the FIFO Polled Mode,
however, the RCVR and XMIT FIFOs are still
fully capable of holding characters.
In this mode, the user's program will check
RCVR and XMITTER status via the LSR. LSR
definitions for the FIFO Polled Mode are as
follows:
79
Table 33 - Baud Rates Using 1.8462 MHz Clock for <= 38.4K; Using 1.8432 MHz Clock
for 115.2k ; Using 3.6864 MHz Clock for 230.4k; Using 7.3728 MHz Clock for 460.8k
DESIRED
DIVISOR USED TO
PERCENT ERROR DIFFERENCE
CRxx:
BAUD RATE
GENERATE 16X CLOCK
BETWEEN DESIRED AND ACTUAL*
BIT 7 OR 6
50
2304
0.001
X
75
1536
X
110
1047
X
134.5
857
0.004
X
150
768
X
300
384
X
600
192
X
1200
96
X
1800
64
X
2000
58
0.005
X
2400
48
X
3600
32
X
4800
24
X
7200
16
X
9600
12
X
19200
6
X
38400
3
0.030
X
57600
2
0.16
X
115200
1
0.16
X
230400
32770
0.16
1
460800
32769
0.16
1
*Note: The percentage error for all baud rates, except where indicated otherwise, is 0.2%.
80
REGISTER/SIGNAL
Table 34 - Reset Function Table
RESET CONTROL
RESET STATE
Interrupt Enable Register
RESET
All bits low
Interrupt Identification Reg.
RESET
Bit 0 is high; Bits 1 - 7 low
FIFO Control
RESET
All bits low
Line Control Reg.
RESET
All bits low
MODEM Control Reg.
RESET
All bits low
Line Status Reg.
RESET
All bits low except 5, 6 high
MODEM Status Reg.
RESET
Bits 0 - 3 low; Bits 4 - 7 input
TXD1, TXD2
RESET
High
INTRPT (RCVR errs)
RESET/Read LSR
Low
INTRPT (RCVR Data Ready)
RESET/Read RBR
Low
INTRPT (THRE)
RESET/ReadIIR/Write THR
Low
OUT2B
RESET
High
RTSB
RESET
High
DTRB
RESET
High
OUT1B
RESET
High
RCVR FIFO
RESET/
FCR1*FCR0/_FCR0
All Bits Low
XMIT FIFO
RESET/
FCR1*FCR0/_FCR0
All Bits Low
81
REGISTER
ADDRESS*
Table 35 - Register Summary for an Individual UART Channel
REGISTER
REGISTER NAME
SYMBOL
BIT 0
BIT 1
ADDR = 0
DLAB = 0
Receive Buffer Register (Read Only)
RBR
Data Bit 0
(Note 1)
Data Bit 1
ADDR = 0
DLAB = 0
Transmitter Holding Register (Write
Only)
THR
Data Bit 0
Data Bit 1
ADDR = 1
DLAB = 0
Interrupt Enable Register
IER
Enable
Received
Data
Available
Interrupt
(ERDAI)
Enable
Transmitter
Holding Register
Empty Interrupt
(ETHREI)
ADDR = 2
Interrupt Ident. Register (Read Only)
IIR
"0" if
Interrupt
Pending
Interrupt ID Bit
ADDR = 2
FIFO Control Register (Write Only)
FCR
FIFO
Enable
RCVR FIFO
Reset
ADDR = 3
Line Control Register
LCR
Word
Length
Select Bit 0
(WLS0)
Word Length
Select Bit 1
(WLS1)
ADDR = 4
MODEM Control Register
MCR
Data
Terminal
Ready
(DTR)
Request to Send
(RTS)
ADDR = 5
Line Status Register
LSR
Data Ready
(DR)
Overrun Error
(OE)
ADDR = 6
MODEM Status Register
MSR
Delta Clear
to Send
(DCTS)
Delta Data Set
Ready (DDSR)
ADDR = 7
Scratch Register (Note 4)
SCR
Bit 0
Bit 1
ADDR = 0
DLAB = 1
Divisor Latch (LS)
DDL
Bit 0
Bit 1
ADDR = 1
DLAB = 1
Divisor Latch (MS)
DLM
Bit 8
Bit 9
*DLAB is Bit 7 of the Line Control Register (ADDR = 3).
Note 1: Bit 0 is the least significant bit. It is the first bit serially transmitted or received.
Note 2: When operating in the XT mode, this bit will be set any time that the transmitter shift
register is empty.
82
Table 35 - Register Summary for an Individual UART Channel (continued)
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
Data Bit 2
Data Bit 3
Data Bit 4
Data Bit 5
Data Bit 6
Data Bit 7
Data Bit 2
Data Bit 3
Data Bit 4
Data Bit 5
Data Bit 6
Data Bit 7
Enable
Receiver Line
Status
Interrupt
(ELSI)
Enable
MODEM
Status
Interrupt
(EMSI)
0
0
0
0
Interrupt ID
Bit
Interrupt ID
Bit (Note 5)
0
0
FIFOs
Enabled
(Note 5)
FIFOs
Enabled
(Note 5)
XMIT FIFO
Reset
DMA Mode
Select
(Note 6)
Reserved
Reserved
RCVR Trigger RCVR Trigger
LSB
MSB
Number of
Stop Bits
(STB)
Parity Enable
(PEN)
Even Parity
Select (EPS)
Stick Parity
Set Break
Divisor Latch
Access Bit
(DLAB)
OUT1
(Note 3)
OUT2
(Note 3)
Loop
0
0
0
Parity Error
(PE)
Framing Error Break
(FE)
Interrupt (BI)
Transmitter
Holding
Register
(THRE)
Transmitter
Empty
(TEMT)
(Note 2)
Error in
RCVR FIFO
(Note 5)
Trailing Edge Delta Data
Clear to Send
Ring Indicator Carrier Detect (CTS)
(TERI)
(DDCD)
Data Set
Ready (DSR)
Ring Indicator Data Carrier
(RI)
Detect (DCD)
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Bit 11
Bit 12
Bit 13
Bit 14
Bit 15
Bit 10
Note 3:
Note 4:
Note 5:
Note 6:
This bit no longer has a pin associated with it.
When operating in the XT mode, this register is not available.
These bits are always zero in the non-FIFO mode.
Writing a one to this bit has no effect. DMA modes are not supported in this chip.
83
interrupt delay will remain active until at
least two bytes have the Tx FIFO empties
after this condition, the Tx been loaded into
the FIFO, concurrently. When interrupt will
be activated without a one character delay.
NOTES ON SERIAL PORT OPERATION
FIFO MODE OPERATION:
GENERAL
The RCVR FIFO will hold up to 16 bytes
regardless of which trigger level is selected.
Rx support functions and operation are quite
different from those described for the
transmitter. The Rx FIFO receives data until the
number of bytes in the FIFO equals the selected
interrupt trigger level.
At that time if Rx
interrupts are enabled, the UART will issue an
interrupt to the CPU. The Rx FIFO will continue
to store bytes until it holds 16 of them. It will
not accept any more data when it is full. Any
more data entering the Rx shift register will set
the Overrun Error flag. Normally, the FIFO
depth and the programmable trigger levels will
give the CPU ample time to empty the Rx FIFO
before an overrun occurs.
TX AND RX FIFO OPERATION
The Tx portion of the UART transmits data
through TXD as soon as the CPU loads a byte
into the Tx FIFO. The UART will prevent
loads to the Tx FIFO if it currently holds 16
characters. Loading to the Tx FIFO will again
be enabled as soon as the next character is
transferred to the Tx shift register. These
capabilities account for the largely autonomous
operation of the Tx.
The UART starts the above operations typically
with a Tx interrupt. The chip issues a Tx
interrupt whenever the Tx FIFO is empty and the
Tx interrupt is enabled, except in the following
instance. Assume that the Tx FIFO is empty
and the CPU starts to load it. When the first
byte enters the FIFO the Tx FIFO empty
interrupt will transition from active to inactive.
Depending on the execution speed of the service
routine software, the UART may be able to
transfer this byte from the FIFO to the shift
register before the CPU loads another byte. If
this happens, the Tx FIFO will be empty again
and typically the UART's interrupt line would
transition to the active state. This could cause a
system with an interrupt control unit to record a
Tx FIFO empty condition, even though the CPU
is currently servicing that interrupt. Therefore,
after the first byte has been loaded into the
FIFO the UART will wait one serial character
transmission time before issuing a new Tx
FIFO empty interrupt. This one character Tx
One side-effect of having a Rx FIFO is that the
selected interrupt trigger level may be above the
data level in the FIFO. This could occur when
data at the end of the block contains fewer bytes
than the trigger level. No interrupt would be
issued to the CPU and the data would remain in
the UART. To prevent the software from
having to check for this situation the chip
incorporates a timeout interrupt.
The timeout interrupt is activated when there is
a least one byte in the Rx FIFO, and neither the
CPU nor the Rx shift register has accessed the
Rx FIFO within 4 character times of the last
byte. The timeout interrupt is cleared or reset
when the CPU reads the Rx FIFO or another
character enters it.
These FIFO-related features allow optimization
of CPU/UART transactions and are especially
useful given the higer baud rate capability (256
kbaud).
84
INFRARED INTERFACE
500 kHz waveform for the duration of the serial
bit time. A “1” is signaled by sending no
transmission the bit time. Please refer to the
AC timing for the parameters of the ASK-IR
waveform.
The infrared interface provides a two-way
wireless communications port using infrared as
a
transmission
medium.
Two
IR
implementations have been provided for the
second UART in this chip (logical device 5),
IrDA and Amplitude Shift Keyed IR. The IR
transmission can use the standard UART2 TX
and RX pins or optional IRTX2 and IRRX2 pins.
These can be selected through the configuration
registers.
If the Half Duplex option is chosen, there is a
time-out when the direction of the transmission
is changed. This time-out starts at the last bit
transferred during a transmission and blocks the
receiver input until the timeout expires. If the
transmit buffer is loaded with more data before
the time-out expires, the timer is restarted after
the new byte is transmitted. If data is loaded
into the transmit buffer while a character is
being received, the transmission will not start
until the time-out expires after the last receive
bit has been received. If the start bit of another
character is received during this time-out, the
timer is restarted after the new character is
received. The IR half duplex time-out is
programmable via CRF2 in Logical Device 5.
This register allows the time-out to be
programmed to any value between 0 and
10msec in 100usec increments.
IrDA allows serial communication at baud rates
up to 115K Baud. Each word is sent serially
beginning with a “0” value start bit. A “0” is
signaled by sending a single IR pulse at the
beginning of the serial bit time. A “1” is signaled
by sending no IR pulse during the bit time.
Please refer to the AC timing for the parameters
of these pulses and the IrDA waveform.
The Amplitude Shift Keyed IR allows serial
communication at baud rates up to 19.2K Baud.
Each word is sent serially beginning with a “0”
value start bit. A zero is signaled by sending a
85
PARALLEL PORT
The parallel port also incorporates SMSC's
ChiProtect circuitry, which prevents possible
damage to the parallel port due to printer powerup.
The FDC37C93xAPM incorporates an IBM
XT/AT compatible parallel port. This supports
the optional PS/2 type bi-directional parallel port
(SPP), the Enhanced Parallel Port (EPP) and
the Extended Capabilities Port (ECP) parallel
port modes.
Refer to the Configuration
Registers for information on disabling, power
down, changing the base address of the parallel
port, and selecting the mode of operation.
The functionality of the parallel port is achieved
through the use of eight addressable ports,
with their associated registers and control
gating. The control and data port are read/write
by the CPU, the status port is read/write in the
EPP mode. The address map of the parallel
port is shown below:
The FDC37C93xAPM also provides a mode for
support of the floppy disk controller on the
parallel port.
DATA PORT
STATUS PORT
CONTROL PORT
EPP ADDR PORT
EPP DATA PORT 0
EPP DATA PORT 1
EPP DATA PORT 2
EPP DATA PORT 3
BASE ADDRESS + 00H
BASE ADDRESS + 01H
BASE ADDRESS + 02H
BASE ADDRESS + 03H
BASE ADDRESS + 04H
BASE ADDRESS + 05H
BASE ADDRESS + 06H
BASE ADDRESS + 07H
The bit map of these registers is:
D0
D1
D2
D3
D4
D5
DATA PORT
PD0
PD1
PD2
PD3
PD4
PD5
STATUS
TMOUT
0
0
nERR
SLCT
PE
PORT
CONTROL
STROBE AUTOFD nINIT
SLC
IRQE
PCD
PORT
EPP ADDR
PD0
PD1
PD2
PD3
PD4
PD5
PORT
EPP DATA
PD0
PD1
PD2
PD3
PD4
PD5
PORT 0
EPP DATA
PD0
PD1
PD2
PD3
PD4
PD5
PORT 1
EPP DATA
PD0
PD1
PD2
PD3
PD4
PD5
PORT 2
EPP DATA
PD0
PD1
PD2
PD3
PD4
PD5
PORT 3
Note 1: These registers are available in all modes.
Note 2: These registers are only available in EPP mode.
Note 3 : For EPP mode, IOCHRDY must be connected to the ISA bus.
86
D6
PD6
nACK
D7
PD7
nBUSY
Note
1
1
0
0
1
PD6
AD7
2,3
PD6
PD7
2,3
PD6
PD7
2,3
PD6
PD7
2,3
PD6
PD7
2,3
Table 36 - Parallel Port Connector
HOST
CONNECTOR
PIN NUMBER
1
STANDARD
EPP
ECP
nStrobe
nWrite
nStrobe
2-9
PData<0:7>
PData<0:7>
PData<0:7>
10
nAck
Intr
nAck
11
Busy
nWait
Busy, PeriphAck(3)
12
PE
(NU)
PError,
nAckReverse(3)
13
Select
(NU)
Select
14
nAutofd
nDatastb
nAutoFd,
HostAck(3)
15
nError
(NU)
nFault(1)
nPeriphRequest(3)
16
nInit
(NU)
nInit(1)
nReverseRqst(3)
17
nSelectin
nAddrstrb
nSelectIn(1,3)
(1) = Compatible Mode
(3) = High Speed Mode
Note: For the cable interconnection required for ECP support and the Slave Connector pin numbers,
refer to the IEEE 1284 Extended Capabilities Port Protocol and ISA Standard, Rev. 1.14,
July 14, 1993. This document is available from Microsoft.
87
BIT 3 nERR - nERROR
The level on the nERROR input is read by the
CPU as bit 3 of the Printer Status Register. A
logic “0” means an error has been detected; a
logic “1” means no error has been detected.
IBM XT/AT COMPATIBLE, BIDIRECTIONAL AND EPP MODES
DATA PORT
ADDRESS OFFSET = 00H
BIT 4 SLCT - PRINTER SELECTED STATUS
The level on the SLCT input is read by the CPU
as bit 4 of the Printer Status Register. A logic
“1” means the printer is on line; a logic “0”
means it is not selected.
The Data Port is located at an offset of '00H'
from the base address. The data register is
cleared at initialization by RESET. During a
WRITE operation, the Data Register latches the
contents of the data bus with the rising edge of
the nIOW input. The contents of this register
are buffered (non inverting) and output onto the
PD0-PD7 ports. During a READ operation in
SPP mode, PD0-PD7 ports are buffered (not
latched) and output to the host CPU.
BIT 5 PE - PAPER END
The level on the PE input is read by the CPU as
bit 5 of the Printer Status Register. A logic “1”
indicates a paper end; a logic “0” indicates the
presence of paper.
STATUS PORT
ADDRESS OFFSET = 01H
BIT 6 nACK - nACKNOWLEDGE
The level on the nACK input is read by the CPU
as bit 6 of the Printer Status Register. A logic
“0” means that the printer has received a
character and can now accept another. A logic
“1” means that it is still processing the last
character or has not received the data.
The Status Port is located at an offset of '01H'
from the base address. The contents of this
register are latched for the duration of an nIOR
read cycle. The bits of the Status Port are
defined as follows:
BIT 0 TMOUT - TIME OUT
This bit is valid in EPP mode only and indicates
that a 10 µsec time out has occured on the EPP
bus. A logic “0” means that no time out error
has occured; a logic “1” means that a time out
error has been detected. This bit is cleared by a
RESET. Writing a “1” to this bit clears the time
out status bit. On a write, this bit is self clearing
and does not require a write of a “0”. Writing a
“0” to this bit has no effect.
BIT 7 nBUSY - nBUSY
The complement of the level on the BUSY input
is read by the CPU as bit 7 of the Printer Status
Register. A logic “0” in this bit means that the
printer is busy and cannot accept a new
character. A logic “1” means that it is ready to
accept the next character.
BIT 1 and 2 - are not implemented as register
bits, during a read of the Printer Status Register
these bits are a low level.
The Control Port is located at an offset of '02H'
from the base address. The Control Register is
initialized by the RESET input, bits 0 to 5 only
being affected; bits 6 and 7 are hard wired low.
CONTROL PORT
ADDRESS OFFSET = 02H
88
EPP ADDRESS PORT
ADDRESS OFFSET = 03H
BIT 0 STROBE - STROBE
This bit is inverted and output onto the
nSTROBE output.
The EPP Address Port is located at an offset of
'03H' from the base address. The address
register is cleared at initialization by RESET.
During a WRITE operation, the contents of DB0DB7 are buffered (non inverting) and output onto
the PD0-PD7 ports, the leading edge of nIOW
causes an EPP ADDRESS WRITE cycle to be
performed, the trailing edge of IOW latches the
data for the duration of the EPP write cycle.
During a READ operation, PD0-PD7 ports are
read, the leading edge of IOR causes an EPP
ADDRESS READ cycle to be performed and the
data output to the host CPU, the deassertion of
ADDRSTB latches the PData for the duration of
the IOR cycle. This register is only available in
EPP mode.
BIT 1 AUTOFD - AUTOFEED
This bit is inverted and output onto the
nAUTOFD output. A logic 1 causes the printer
to generate a line feed after each line is printed.
A logic “0” means no autofeed.
BIT 2 nINIT - nINITIATE OUTPUT
This bit is output onto the nINIT output without
inversion.
BIT 3 SLCTIN - PRINTER SELECT INPUT
This bit is inverted and output onto the nSLCTIN
output. A logic 1 on this bit selects the printer; a
logic 0 means the printer is not selected.
BIT 4 IRQE - INTERRUPT REQUEST ENABLE
The interrupt request enable bit when set to a
high level may be used to enable interrupt
requests from the Parallel Port to the CPU. An
interrupt request is generated on the IRQ port by
a positive going nACK input. When the IRQE
bit is programmed low the IRQ is disabled.
EPP DATA PORT 0
ADDRESS OFFSET = 04H
The EPP Data Port 0 is located at an offset of
'04H' from the base address. The data register
is cleared at initialization by RESET. During a
WRITE operation, the contents of DB0-DB7 are
buffered (non-inverting) and output onto the PD0
- PD7 ports, the leading edge of nIOW causes
an EPP DATA WRITE cycle to be performed,
the trailing edge of IOW latches the data for the
duration of the EPP write cycle. During a READ
operation, PD0-PD7 ports are read, the leading
edge of IOR causes an EPP READ cycle to be
performed and the data output to the host CPU,
the deassertion of DATASTB latches the PData
for the duration of the IOR cycle. This register
is only available in EPP mode.
BIT 5
PCD - PARALLEL CONTROL
DIRECTION
Parallel Control Direction is not valid in printer
mode. In printer mode, the direction is always
out regardless of the state of this bit. In bidirectional, EPP or ECP mode, a logic “0”
means that the printer port is in output mode
(write); a logic 1 means that the printer port is in
input mode (read).
Bits 6 and 7 during a read are a low level, and
cannot be written.
89
EPP DATA PORT 1
ADDRESS OFFSET = 05H
deasserted (after command). If a time-out
occurs, the current EPP cycle is aborted and the
time-out condition is indicated in Status bit 0.
The EPP Data Port 1 is located at an offset of
'05H' from the base address. Refer to EPP
DATA PORT 0 for a description of operation.
This register is only available in EPP mode.
EPP DATA PORT 2
ADDRESS OFFSET = 06H
During an EPP cycle, if STROBE is active, it
overrides the EPP write signal forcing the PDx
bus to always be in a write mode and the
nWRITE signal to always be asserted.
Software Constraints
The EPP Data Port 2 is located at an offset of
'06H' from the base address. Refer to EPP
DATA PORT 0 for a description of operation.
This register is only available in EPP mode.
Before an EPP cycle is executed, the software
must ensure that the control register bit PCD is
a logic "0" (ie a 04H or 05H should be written to
the Control port). If the user leaves PCD as a
logic "1", and attempts to perform an EPP write,
the chip is unable to perform the write (because
PCD is a logic "1") and will appear to perform an
EPP read on the parallel bus; no error is
indicated.
EPP DATA PORT 3
ADDRESS OFFSET = 07H
The EPP Data Port 3 is located at an offset of
'07H' from the base address. Refer to EPP
DATA PORT 0 for a description of operation.
This register is only available in EPP mode.
EPP 1.9 Write
The timing for a write operation (address or
data) is shown in timing diagram EPP Write
Data or Address cycle. IOCHRDY is driven
active low at the start of each EPP write and is
released when it has been determined that the
write cycle can complete. The write cycle can
complete under the following circumstances:
EPP 1.9 OPERATION
When the EPP mode is selected in the
configuration register, the standard and bidirectional modes are also available. If no EPP
Read, Write or Address cycle is currently
executing, then the PDx bus is in the standard or
bi-directional mode, and all output signals
(STROBE, AUTOFD, INIT) are as set by the
SPP Control Port and direction is controlled by
PCD of the Control port.
In EPP mode, the system timing is closely
coupled to the EPP timing. For this reason, a
watchdog timer is required to prevent system
lockup. The timer indicates if more than 10
µsec have elapsed from the start of the EPP
cycle (nIOR or nIOW asserted) to nWAIT being
90
1.
If the EPP bus is not ready (nWAIT is active
low) when nDATASTB or nADDRSTB goes
active then the write can complete when
nWAIT goes inactive high.
2.
If the EPP bus is ready (nWAIT is inactive
high) then the chip must wait for it to go
active low before changing the state of
nDATASTB, nWRITE or nADDRSTB. The
write can complete once nWAIT is
determined inactive.
Write Sequence of Operation
1.
2.
3.
4.
5.
6.
7.
8.
9.
The host selects an EPP register, places
data on the SData bus and drives nIOW
active.
The chip drives IOCHRDY inactive (low).
If WAIT is not asserted, the chip must wait
until WAIT is asserted.
The chip places address or data on PData
bus, clears PDIR, and asserts nWRITE.
Chip asserts nDATASTB or nADDRSTRB
indicating that PData bus contains valid
information, and the WRITE signal is valid.
Peripheral deasserts nWAIT, indicating that
any setup requirements have been satisfied
and the chip may begin the termination
phase of the cycle.
a) The chip deasserts nDATASTB or
nADDRSTRB, this marks the beginning
of the termination phase. If it has not
already done so, the peripheral should
latch the information byte now.
b) The chip latches the data from the
SData bus for the PData bus and
asserts (releases) IOCHRDY allowing
the host to complete the write cycle.
Peripheral asserts nWAIT, indicating to the
host that any hold time requirements have
been satisfied and acknowledging the
termination of the cycle.
Chip may modify nWRITE and nPDATA in
preparation for the next cycle.
1.
If the EPP bus is not ready (nWAIT is active
low) when nDATASTB goes active then the
read can complete when nWAIT goes
inactive high.
2.
If the EPP bus is ready (nWAIT is inactive
high) then the chip must wait for it to go
active low before changing the state of
WRITE or before nDATASTB goes active.
The read can complete once nWAIT is
determined inactive.
Read Sequence of Operation
1.
The host selects an EPP register and drives
nIOR active.
2. The chip drives IOCHRDY inactive (low).
3. If WAIT is not asserted, the chip must wait
until WAIT is asserted.
4. The chip tri-states the PData bus and
deasserts nWRITE.
5. Chip asserts nDATASTB or nADDRSTRB
indicating that PData bus is tri-stated, PDIR
is set and the nWRITE signal is valid.
6. Peripheral drives PData bus valid.
7. Peripheral deasserts nWAIT, indicating that
PData is valid and the chip may begin the
termination phase of the cycle.
8. a) The chip latches the data from the
PData bus for the SData bus and
deasserts nDATASTB or nADDRSTRB.
This marks the beginning of the
termination phase.
b) The chip drives the valid data onto the
SData bus and asserts (releases)
IOCHRDY allowing the host to
complete the read cycle.
9. Peripheral tri-states the PData bus and
asserts nWAIT, indicating to the host that
the PData bus is tri-stated.
10. Chip may modify nWRITE, PDIR and
nPDATA in preparation for the next cycle.
EPP 1.9 Read
The timing for a read operation (data) is shown
in timing diagram EPP Read Data cycle.
IOCHRDY is driven active low at the start of
each EPP read and is released when it has been
determined that the read cycle can complete.
The read cycle can complete under the following
circumstances:
91
EPP 1.7 OPERATION
Write Sequence of Operation
When the EPP 1.7 mode is selected in the
configuration register, the standard and bidirectional modes are also available. If no EPP
Read, Write or Address cycle is currently
executing, then the PDx bus is in the standard or
bi-directional mode, and all output signals
(STROBE, AUTOFD, INIT) are as set by the
SPP Control Port and direction is controlled by
PCD of the Control port.
1.
2.
3.
4.
In EPP mode, the system timing is closely
coupled to the EPP timing. For this reason, a
watchdog timer is required to prevent system
lockup. The timer indicates if more than 10
µsec have elapsed from the start of the EPP
cycle (nIOR or nIOW asserted) to the end of the
cycle nIOR or nIOW deasserted). If a time-out
occurs, the current EPP cycle is aborted and the
time-out condition is indicated in Status bit 0.
5.
6.
7.
The host sets PDIR bit in the control
register to a logic "0".
This asserts
nWRITE.
The host selects an EPP register, places
data on the SData bus and drives nIOW
active.
The chip places address or data on PData
bus.
Chip asserts nDATASTB or nADDRSTRB
indicating that PData bus contains valid
information, and the WRITE signal is valid.
If nWAIT is asserted, IOCHRDY is
deasserted until the peripheral deasserts
nWAIT or a time-out occurs.
When the host deasserts nIOW the chip
deasserts nDATASTB or nADDRSTRB and
latches the data from the SData bus for the
PData bus.
Chip may modify nWRITE, PDIR and
nPDATA in preparation of the next cycle.
Software Constraints
EPP 1.7 Read
Before an EPP cycle is executed, the software
must ensure that the control register bits D0, D1
and D3 are set to zero. Also, bit D5 (PCD) is a
logic "0" for an EPP write or a logic "1" for and
EPP read.
The timing for a read operation (data) is shown
in timing diagram EPP 1.7 Read Data cycle.
IOCHRDY is driven active low when nWAIT is
active low during the EPP cycle. This can be
used to extend the cycle time. The read cycle
can complete when nWAIT is inactive high.
EPP 1.7 Write
Read Sequence of Operation
The timing for a write operation (address or
data) is shown in timing diagram EPP 1.7 Write
Data or Address cycle. IOCHRDY is driven
active low when nWAIT is active low during the
EPP cycle. This can be used to extend the cycle
time.
The write cycle can complete when
nWAIT is inactive high.
1.
2.
3.
4.
5.
92
The host sets PDIR bit in the control
register to a logic "1". This deasserts
nWRITE and tri-states the PData bus.
The host selects an EPP register and drives
nIOR active.
Chip asserts nDATASTB or nADDRSTRB
indicating that PData bus is tri-stated, PDIR
is set and the nWRITE signal is valid.
If nWAIT is asserted, IOCHRDY is
deasserted until the peripheral deasserts
nWAIT or a time-out occurs.
The Peripheral drives PData bus valid.
6.
7.
8.
9.
The Peripheral deasserts nWAIT, indicating
that PData is valid and the chip may begin
the termination phase of the cycle.
When the host deasserts nIOR the chip
deasserts nDATASTB or nADDRSTRB.
93
Peripheral tri-states the PData bus.
Chip may modify nWRITE, PDIR and
nPDATA in preparation of the next cycle.
Table 37 - EPP Pin Descriptions
EPP
SIGNAL
EPP NAME
TYPE
EPP DESCRIPTION
nWRITE
nWrite
O
This signal is active low. It denotes a write operation.
PD<0:7>
Address/Data
I/O
Bi-directional EPP byte wide address and data bus.
INTR
Interrupt
I
This signal is active high and positive edge triggered. (Pass
through with no inversion, Same as SPP.)
WAIT
nWait
I
This signal is active low. It is driven inactive as a positive
acknowledgement from the device that the transfer of data
is completed. It is driven active as an indication that the
device is ready for the next transfer.
DATASTB
nData Strobe
O
This signal is active low.
write operation.
RESET
nReset
O
This signal is active low.
When driven active, the EPP
device is reset to its initial operational mode.
ADDRSTB
nAddress
Strobe
O
This signal is active low.
or write operation.
PE
Paper End
I
Same as SPP mode.
SLCT
Printer
Selected
Status
I
Same as SPP mode.
nERR
Error
I
Same as SPP mode.
PDIR
Parallel Port
Direction
O
This output shows the direction of the data transfer on the
parallel port bus. A low means an output/write condition and
a high means an input/read condition. This signal is
normally a low (output/write) unless PCD of the control
register is set or if an EPP read cycle is in progress.
It is used to denote data read or
It is used to denote address read
Note 1: SPP and EPP can use one common register.
Note 2: nWrite is the only EPP output that can be over-ridden by SPP control port during an EPP
cycle. For correct EPP read cycles, PCD is required to be a low.
94
reverse: Peripheral to Host communication
Pword:
A port word; equal in size to
the
width of the ISA interface. For this
implementation, PWord is always 8
bits.
1
A high level.
0
A low level.
EXTENDED CAPABILITIES PARALLEL PORT
ECP provides a number of advantages, some of
which are listed below. The individual features
are explained in greater detail in the remainder
of this section.
•
•
•
•
•
•
•
•
High performance half-duplex forward and
reverse channel
Interlocked handshake, for fast reliable
transfer
Optional single byte RLE compression for
improved throughput (64:1)
Channel addressing for low-cost peripherals
Maintains link and data layer separation
Permits the use of active output drivers
Permits the use of adaptive signal timing
Peer-to-peer capability
These terms may be considered synonymous:
•
•
•
•
•
•
•
•
•
Vocabulary
The following terms are used in this document:
PeriphClk, nAck
HostAck, nAutoFd
PeriphAck, Busy
nPeriphRequest, nFault
nReverseRequest, nInit
nAckReverse, PError
Xflag, Select
ECPMode, nSelectln
HostClk, nStrobe
Reference Document:
IEEE 1284 Extended Capabilities Port Protocol
and ISA Interface Standard, Rev 1.14, July 14,
1993.
This document is available from
Microsoft.
assert:
When a signal asserts it transitions
to a "true" state, when a signal
deasserts it transitions to a "false"
state.
forward: Host to Peripheral communication.
The bit map of the Extended Parallel Port
registers is shown in the table on the following
page.
95
data
ecpAFifo
D7
D6
D5
D4
D3
D2
D1
D0
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
Select
nFault
0
0
0
1
ackIntEn
SelectIn
nInit
autofd
strobe
1
Addr/RLE
Address or RLE field
dsr
nBusy
nAck
PError
dcr
0
0
Direction
cFifo
ecpDFifo
tFifo
0
0
cnfgB
compress
intrValue
ecr
2
Parallel Port Data FIFO
2
ECP Data FIFO
2
Test FIFO
cnfgA
MODE
0
Note
1
2
0
0
dmaEn
serviceIntr
Parallel Port IRQ
nErrIntrEn
0
0
Parallel Port DMA
full
empty
Note 1: These registers are available in all modes.
Note 2: All FIFOs use one common 16 byte FIFO.
Note 3: The ECP Parallel Port Config Reg B reflects the IRQ and DRQ selected by the Configuration
Registers.
It does not do any "protocol" negotiation, rather
it provides an automatic high burst-bandwidth
ISA IMPLEMENTATION STANDARD
channel that supports DMA for ECP in both the
forward and reverse directions.
This specification describes the standard ISA
interface to the Extended Capabilities Port
Small FIFOs are employed in both forward and
(ECP). All ISA devices supporting ECP must
reverse directions to smooth data flow and
meet the requirements contained in this section
improve the maximum bandwidth requirement.
or the port will not be supported by Microsoft.
The size of the FIFO is 16 bytes deep. The port
For a description of the ECP Protocol, please
supports an automatic handshake for the
refer to the IEEE 1284 Extended Capabilities
standard parallel port to improve compatibility
Port Protocol and ISA Interface Standard, Rev.
mode transfer speed.
1.14, July 14, 1993. This document is available
from Microsoft.
The port also supports run length encoded
(RLE) decompression (required) in hardware.
Description
Compression is accomplished by counting
identical bytes and transmitting an RLE byte
The port is software and hardware compatible
that indicates how many times the next byte is
with existing parallel ports so that it may be
to be repeated. Decompression simply
used as a standard LPT port if ECP is not
intercepts the RLE byte and repeats the
required. The port is designed to be simple and
following byte the specified number of times.
requires a small number of gates to implement.
Hardware support for compression is optional.
96
NAME
TYPE
Table 38 - ECP Pin Descriptions
DESCRIPTION
nStrobe
O
During write operations nStrobe registers data or address into the slave
on the asserting edge (handshakes with Busy).
PData 7:0
I/O
Contains address or data or RLE data.
nAck
I
Indicates valid data driven by the peripheral when asserted. This signal
handshakes with nAutoFd in reverse.
PeriphAck (Busy)
I
This signal deasserts to indicate that the peripheral can accept data.
This signal handshakes with nStrobe in the forward direction. In the
reverse direction this signal indicates whether the data lines contain
ECP command information or data. The peripheral uses this signal to
flow control in the forward direction. It is an "interlocked" handshake
with nStrobe. PeriphAck also provides command information in the
reverse direction.
PError
(nAckReverse)
I
Used to acknowledge a change in the direction the transfer (asserted =
forward).
The peripheral drives this signal low to acknowledge
nReverseRequest.
It
is
an
"interlocked"
handshake
with
nReverseRequest. The host relies upon nAckReverse to determine
when it is permitted to drive the data bus.
Select
I
Indicates printer on line.
nAutoFd
(HostAck)
O
Requests a byte of data from the peripheral when asserted,
handshaking with nAck in the reverse direction. In the forward direction
this signal indicates whether the data lines contain ECP address or
data. The host drives this signal to flow control in the reverse direction.
It is an "interlocked" handshake with nAck. HostAck also provides
command information in the forward phase.
nFault
(nPeriphRequest)
I
Generates an error interrupt when asserted. This signal provides a
mechanism for peer-to-peer communication. This signal is valid only in
the forward direction. During ECP Mode the peripheral is permitted
(but not required) to drive this pin low to request a reverse transfer. The
request is merely a "hint" to the host; the host has ultimate control over
the transfer direction. This signal would be typically used to generate
an interrupt to the host CPU.
nInit
O
Sets the transfer direction (asserted = reverse, deasserted = forward).
This pin is driven low to place the channel in the reverse direction. The
peripheral is only allowed to drive the bi-directional data bus while in
ECP Mode and HostAck is low and nSelectIn is high.
nSelectIn
O
Always deasserted in ECP mode.
97
to avoid conflict with standard ISA devices. The
port is equivalent to a generic parallel port
interface and may be operated in that mode.
The port registers vary depending on the mode
field in the ecr. The table below lists these
dependencies. Operation of the devices in
modes other that those specified is undefined.
Register Definitions
The register definitions are based on the
standard IBM addresses for LPT. All of the
standard printer ports are supported.
The
additional registers attach to an upper bit
decode of the standard LPT port definition
Table 39 - ECP Register Definitions
ADDRESS (Note 1)
ECP MODES
NAME
FUNCTION
data
+000h R/W
000-001
Data Register
ecpAFifo
+000h R/W
011
ECP FIFO (Address)
dsr
+001h R/W
All
Status Register
dcr
+002h R/W
All
Control Register
cFifo
+400h R/W
010
Parallel Port Data FIFO
ecpDFifo
+400h R/W
011
ECP FIFO (DATA)
tFifo
+400h R/W
110
Test FIFO
cnfgA
+400h R
111
Configuration Register A
cnfgB
+401h R/W
111
Configuration Register B
ecr
+402h R/W
All
Extended Control Register
Note 1: These addresses are added to the parallel port base address as selected by configuration
register or jumpers.
Note 2: All addresses are qualified with AEN. Refer to the AEN pin definition.
Table 40 - Mode Descriptions
DESCRIPTION*
MODE
000
SPP mode
001
PS/2 Parallel Port mde
010
Parallel Port Data FIFO mode
011
ECP Parallel Port mode
100
EPP mode (If this option is enabled in the configuration registers)
101
(Reserved)
110
Test mode
111
Configuration mode
*Refer to ECR Register Description
98
BIT 4 Select
The level on the Select input is read by the CPU
as bit 4 of the Device Status Register.
DATA and ecpAFifo PORT
ADDRESS OFFSET = 00H
Modes 000 and 001 (Data Port)
BIT 5 PError
The level on the PError input is read by the CPU
as bit 5 of the Device Status Register. Printer
Status Register.
The Data Port is located at an offset of '00H'
from the base address. The data register is
cleared at initialization by RESET. During a
WRITE operation, the Data Register latches the
contents of the data bus on the rising edge of
the nIOW input. The contents of this register
are buffered (non inverting) and output onto the
PD0-PD7 ports. During a READ operation,
PD0-PD7 ports are read and output to the host
CPU.
BIT 6 nAck
The level on the nAck input is read by the CPU
as bit 6 of the Device Status Register.
BIT 7 nBusy
The complement of the level on the BUSY input
is read by the CPU as bit 7 of the Device Status
Register.
Mode 011 (ECP FIFO - Address/RLE)
A data byte written to this address is placed in
the FIFO and tagged as an ECP Address/RLE.
The hardware at the ECP port transmits this
byte to the peripheral automatically. The
operation of this register is ony defined for the
forward direction (direction is 0). Refer to the
ECP Parallel Port Forward Timing Diagram,
located in the Timing Diagrams section of this
data sheet.
DEVICE CONTROL REGISTER (dcr)
ADDRESS OFFSET = 02H
The Control Register is located at an offset of
'02H' from the base address. The Control
Register is initialized to zero by the RESET
input, bits 0 to 5 only being affected; bits 6 and
7 are hard wired low.
DEVICE STATUS REGISTER (dsr)
ADDRESS OFFSET = 01H
BIT 0 STROBE - STROBE
This bit is inverted and output onto the
nSTROBE output.
The Status Port is located at an offset of '01H'
from the base address.
Bits 0-2 are not
implemented as register bits, during a read of
the Printer Status Register these bits are a low
level. The bits of the Status Port are defined as
follows:
BIT 1 AUTOFD - AUTOFEED
This bit is inverted and output onto the
nAUTOFD output. A logic 1 causes the printer
to generate a line feed after each line is printed.
A logic 0 means no autofeed.
BIT 2 nINIT - nINITIATE OUTPUT
This bit is output onto the nINIT output without
inversion.
BIT 3 nFault
The level on the nFault input is read by the CPU
as bit 3 of the Device Status Register.
BIT 3 SELECTIN
This bit is inverted and output onto the nSLCTIN
output. A logic 1 on this bit selects the printer; a
logic 0 means the printer is not selected.
99
Data bytes from the peripheral are read under
automatic hardware handshake from ECP into
this FIFO when the direction bit is 1. Reads or
DMAs from the FIFO will return bytes of ECP
data to the system.
BIT 4 ackIntEn - INTERRUPT REQUEST
ENABLE
The interrupt request enable bit when set to a
high level may be used to enable interrupt
requests from the Parallel Port to the CPU due
to a low to high transition on the nACK input.
Refer to the description of the interrupt under
Operation, Interrupts.
tFifo (Test FIFO Mode)
ADDRESS OFFSET = 400H
Mode = 110
Data bytes may be read, written or DMAed to or
from the system to this FIFO in any direction.
BIT 5 DIRECTION
If mode=000 or mode=010, this bit has no effect
and the direction is always out regardless of the
state of this bit. In all other modes, Direction is
valid and a logic 0 means that the printer port is
in output mode (write); a logic 1 means that the
printer port is in input mode (read).
Data in the tFIFO will not be transmitted to the
parallel port lines using a hardware protocol
handshake. However, data in the tFIFO may be
displayed on the parallel port data lines.
The tFIFO will not stall when overwritten or
underrun. If an attempt is made to write data to
a full tFIFO, the new data is not accepted into
the tFIFO. If an attempt is made to read data
from an empty tFIFO, the last data byte is reread again. The full and empty bits must
always keep track of the correct FIFO state. The
tFIFO will transfer data at the maximum ISA
rate so that software may generate performance
metrics.
BITS 6 and 7 during a read are a low level, and
cannot be written.
cFifo (Parallel Port Data FIFO)
ADDRESS OFFSET = 400h
Mode = 010
Bytes written or DMAed from the system to this
FIFO are transmitted by a hardware handshake
to the peripheral using the standard parallel port
protocol.
Transfers to the FIFO are byte
aligned. This mode is only defined for the
forward direction.
The FIFO size and interrupt threshold can be
determined by writing bytes to the FIFO and
checking the full and serviceIntr bits.
ecpDFifo (ECP Data FIFO)
ADDRESS OFFSET = 400H
Mode = 011
The writeIntrThreshold can be determined by
starting with a full tFIFO, setting the direction bit
to 0 and emptying it a byte at a time until
serviceIntr is set. This may generate a spurious
interrupt, but will indicate that the threshold has
been reached.
Bytes written or DMAed from the system to this
FIFO, when the direction bit is 0, are transmitted
by a hardware handshake to the peripheral
using the ECP parallel port protocol. Transfers
to the FIFO are byte aligned.
The readIntrThreshold can be determined by
setting the direction bit to 1 and filling the empty
tFIFO a byte at a time until serviceIntr is set.
This may generate a spurious interrupt, but will
indicate that the threshold has been reached.
100
Data bytes are always read from the head of
tFIFO regardless of the value of the direction bit.
For example if 44h, 33h, 22h are written to the
FIFO, then reading the tFIFO will return 44h,
33h, 22h in the same order as was written.
BITS 7 - 5
These bits are Read/Write and select the Mode.
BIT 4 nErrIntrEn
Read/Write (Valid only in ECP Mode)
1: Disables the interrupt generated on the
asserting edge of nFault.
0: Enables an interrupt pulse on the high to
low edge of nFault. Note that an interrupt
will be generated if nFault is asserted
(interrupting) and this bit is written from a
“1” to a “0”. This prevents interrupts from
being lost in the time between the read of
the ecr and the write of the ecr.
cnfgA (Configuration Register A)
ADDRESS OFFSET = 400H
Mode = 111
This register is a read-only register. When read,
10H is returned. This indicates to the system
that this is an 8-bit implementation. (PWord = 1
byte)
BIT 3 dmaEn
Read/Write
1: Enables DMA (DMA starts when serviceIntr
is 0).
0: Disables DMA unconditionally.
cnfgB (Configuration Register B)
ADDRESS OFFSET = 401H
Mode = 111
BIT 7 compress
This bit is read only. During a read it is a low
level. This means that this chip does not
support hardware RLE compression. It does
support hardware de-compression!
BIT 2 serviceIntr
Read/Write
1: Disables DMA and all of the service
interrupts.
0: Enables one of the following three cases of
interrupts. Once one of the three service
interrupts has occurred serviceIntr bit shall
be set to a “1” by hardware. It must be reset
to “0” to re-enable the interrupts. Writing
this bit to a “1” will not cause an interrupt.
case dmaEn=1:
During DMA (this bit is set to a “1” when
terminal count is reached).
case dmaEn=0 direction=0:
This bit shall be set to 1 whenever there are
writeIntrThreshold or more bytes free in the
FIFO.
case dmaEn=0 direction=1:
This bit shall be set to 1 whenever there are
readIntrThreshold or more valid bytes to be
read from the FIFO.
BIT 6 intrValue
Returns the value on the ISA IRQ line to
determine possible conflicts.
BITS 3 - 0 Parallel Port IRQ
Refer to Table 41B.
BITS 2 - 0 Parallel Port DMA
Refer to Table 41C.
ecr (Extended Control Register)
ADDRESS OFFSET = 402H
Mode = all
This register controls the extended ECP parallel
port functions.
101
BIT 0 empty
Read only
1: The FIFO is completely empty.
0: The FIFO contains at least one byte of data.
BIT 1 full
Read only
1: The FIFO cannot accept another byte or the
FIFO is completely full.
0: The FIFO has at least one free byte.
102
Table 41A - Extended Control Register
MODE
R/W
000:
Standard Parallel Port Mode. In this mode the FIFO is reset and common collector drivers
are used on the control lines (nStrobe, nAutoFd, nInit and nSelectIn). Setting the direction
bit will not tri-state the output drivers in this mode.
001:
PS/2 Parallel Port Mode. Same as above except that direction may be used to tri-state the
data lines and reading the data register returns the value on the data lines and not the
value in the data register. All drivers have active pull-ups (push-pull).
010:
Parallel Port FIFO Mode. This is the same as 000 except that bytes are written or DMAed to
the FIFO. FIFO data is automatically transmitted using the standard parallel port protocol.
Note that this mode is only useful when direction is 0. All drivers have active pull-ups
(push-pull).
011:
ECP Parallel Port Mode. In the forward direction (direction is 0) bytes placed into the
ecpDFifo and bytes written to the ecpAFifo are placed in a single FIFO and transmitted
automatically to the peripheral using ECP Protocol. In the reverse direction (direction is 1)
bytes are moved from the ECP parallel port and packed into bytes in the ecpDFifo. All
drivers have active pull-ups (push-pull).
100:
Selects EPP Mode: In this mode, EPP is selected if the EPP supported option is selected in
configuration register L3-CRF0. All drivers have active pull-ups (push-pull).
101:
Reserved
110:
Test Mode. In this mode the FIFO may be written and read, but the data will not be
transmitted on the parallel port. All drivers have active pull-ups (push-pull).
111:
Configuration Mode. In this mode the confgA, confgB registers are accessible at 0x400 and
0x401. All drivers have active pull-ups (push-pull).
Table 41B
CONFIG REG B
IRQ SELECTED
BITS 5:3
Table 41C
CONFIG REG B
BITS 2:0
DMA SELECTED
15
110
3
011
14
101
2
010
11
100
1
001
10
011
All Others
000
9
010
7
001
5
111
All Others
000
103
After negotiation, it is necessary to initialize
some of the port bits. The following are required:
OPERATION
Mode Switching/Software Control
•
•
Software will execute P1284 negotiation and all
operation prior to a data transfer phase under
programmed I/O control (mode 000 or 001).
Hardware provides an automatic control line
handshake, moving data between the FIFO and
the ECP port only in the data transfer phase
(modes 011 or 010).
•
•
Set Direction = 0, enabling the drivers.
Set strobe = 0, causing the nStrobe signal
to default to the deasserted state.
Set autoFd = 0, causing the nAutoFd
signal to default to the deasserted state.
Set mode = 011 (ECP Mode)
ECP address/RLE bytes or data bytes may be
sent automatically by writing the ecpAFifo or
ecpDFifo respectively.
Setting the mode to 011 or 010 will cause the
hardware to initiate data transfer.
Note that all FIFO data transfers are byte wide
and byte aligned. Address/RLE transfers are
byte-wide and only allowed in the forward
direction.
If the port is in mode 000 or 001 it may switch to
any other mode. If the port is not in mode 000
or 001 it can only be switched into mode 000 or
001. The direction can only be changed in
mode 001.
The host may switch directions by first switching
to mode = 001, negotiating for the forward or
reverse channel, setting
direction to 1 or 0,
then setting mode = 011. When direction is 1
the hardware shall handshake for each ECP
read data byte and attempt to fill the FIFO.
Bytes may then be read from the ecpDFifo as
long as it is not empty.
Once in an extended forward mode the software
should wait for the FIFO to be empty before
switching back to mode 000 or 001. In this case
all control signals will be deasserted before the
mode switch. In an ecp reverse mode the
software waits for all the data to be read from
the FIFO before changing back to mode 000 or
001. Since the automatic hardware ecp reverse
handshake only cares about the state of the
FIFO it may have acquired extra data which will
be discarded. It may in fact be in the middle of a
transfer when the mode is changed back to 000
or 001. In this case the port will deassert
nAutoFd independent of the state of the transfer.
The design shall not cause glitches on the
handshake signals if the software meets the
constraints above.
ECP transfers may also be accomplished (albeit
slowly) by handshaking individual bytes under
program control in mode = 001, or 000.
Termination from ECP Mode
Termination from ECP Mode is similar to the
termination from Nibble/Byte Modes. The host is
permitted to terminate from ECP Mode only in
specific well-defined states. The termination can
only be executed while the bus is in the forward
direction. To terminate while the channel is in
the reverse direction, it must first be transitioned
into the forward direction.
ECP Operation
Prior to ECP operation the Host must negotiate
on the parallel port to determine if the peripheral
supports the ECP protocol. This is a somewhat
complex negotiation carried out under program
control in mode 000.
104
is not supported. To transfer compressed data
in ECP mode, the compression count is written
to the ecpAFifo and the data byte is written to
the ecpDFifo.
Command/Data
ECP Mode supports two advanced features to
improve the effectiveness of the protocol for
some
applications.
The
features
are
implemented by allowing the transfer of normal
8-bit data or 8-bit commands.
Compression is accomplished by counting
identical bytes and transmitting an RLE byte
that indicates how many times the next byte is
to be repeated. Decompression simply
intercepts the RLE byte and repeats the
following byte the specified number of times.
When a run-length count is received from a
peripheral, the subsequent data byte is
replicated the specified number of times. A
run-length count of zero specifies that only one
byte of data is represented by the next data
byte, whereas a run-length
count
of 127
indicates that the next byte should be expanded
to 128 bytes. To prevent data expansion,
however, run-length counts of zero should be
avoided.
When in the forward direction, normal data is
transferred when HostAck is high and an 8-bit
command is transferred when HostAck is low.
The most significant bit of the command
indicates whether it is a run-length count (for
compression) or a channel address.
When in the reverse direction, normal data is
transferred when PeriphAck is high and an 8-bit
command is transferred when PeriphAck is low.
The most significant bit of the command is
always zero. Reverse channel addresses are
seldom used and may not be supported in
hardware.
Pin Definition
The drivers for nStrobe, nAutoFd, nInit and
nSelectIn are open-collector in mode 000 and
are push-pull in all other modes.
Table 42
Forward Channel Commands (HostAck Low)
Reverse Channel Commands (PeripAck Low)
D7
D[6:0]
0
Run-Length Count (0-127)
(mode 0011 0X00 only)
1
Channel Address (0-127)
ISA Connections
The interface can never stall causing the host to
hang. The width of data transfers is strictly
controlled on an I/O address basis per this
specification. All FIFO-DMA transfers are byte
wide, byte aligned and end on a byte boundary.
(The PWord value can be obtained by reading
Configuration Register A, cnfgA, described in
the next section.) Single byte wide transfers
are always possible with standard or PS/2 mode
using program control of the control signals.
Data Compression
The ECP port supports run length encoded
(RLE) decompression in hardware and can
transfer compressed data to a peripheral. Run
length encoded (RLE) compression in hardware
105
readIntrThreshold or more
bytes in the FIFO. Also, an
interrupt is generated when
serviceIntr is cleared to 0
whenever
there
are
readIntrThreshold or more
bytes in the FIFO.
Interrupts
The interrupts are enabled by serviceIntr in the
ecr register.
serviceIntr = 1 Disables the DMA and all of the
service interrupts.
serviceIntr = 0
3. When nErrIntrEn is 0 and nFault transitions
from high to low or when nErrIntrEn is set
from 1 to 0 and nFault is asserted.
Enables the selected interrupt
condition. If the interrupting
condition is valid, then the
interrupt
is
generated
immediately when this bit is
changed from a 1 to a 0. This
can occur during Programmed
I/O if the number of bytes
removed or added from/to the
FIFO does not cross the
threshold.
4. When ackIntEn is 1 and the nAck signal
transitions from a low to a high.
FIFO Operation
The FIFO threshold is set in the chip
configuration registers. All data transfers to or
from the parallel port can proceed in DMA or
Programmed I/O (non-DMA) mode as indicated
by the selected mode. The FIFO is used by
selecting the Parallel Port FIFO mode or ECP
Parallel Port Mode. (FIFO test mode will be
addressed separately.) After a reset, the FIFO
is disabled. Each data byte is transferred by a
Programmed I/O cycle or PDRQ depending on
the selection of DMA or Programmed I/O mode.
The interrupt generated is ISA friendly in that it
must pulse the interrupt line low, allowing for
interrupt sharing.
After a brief pulse low
following the interrupt event, the interrupt line is
tri-stated so that other interrupts may assert.
An interrupt is generated when:
1. For DMA transfers: When serviceIntr is 0,
dmaEn is 1 and the DMA TC is received.
The following paragraphs detail the operation of
the FIFO flow control. In these descriptions,
<threshold> ranges from 1 to 16.
The
parameter FIFOTHR, which the user programs,
is one less and ranges from 0 to 15.
2. For Programmed I/O:
a.
When serviceIntr is 0, dmaEn is 0,
direction is 0 and there are
writeIntrThreshold or more free bytes in
the FIFO.
Also, an interrupt is
generated when serviceIntr is cleared
to
0
whenever
there
are
writeIntrThreshold or more free bytes in
the FIFO.
b.
(1) When serviceIntr is 0, dmaEn is
0, direction is 1 and there are
A low threshold value (i.e. 2) results in longer
periods of time between service requests, but
requires faster servicing of the request for both
read and write cases. The host must be very
responsive to the service request. This is the
desired case for use with a "fast" system. A
high value of threshold (i.e. 12) is used with a
"sluggish" system by affording a long latency
period after a service request, but results in
more frequent service requests.
106
DMA Mode - Transfers from the FIFO to the
Host
DMA TRANSFERS
DMA transfers are always to or from the
ecpDFifo, tFifo or CFifo. DMA utilizes the
standard PC DMA services. To use the DMA
transfers, the host first sets up the direction and
state as in the programmed I/O case. Then it
programs the DMA controller in the host with the
desired count and memory address. Lastly it
sets dmaEn to 1 and serviceIntr to 0. The ECP
requests DMA transfers from the host by
activating the PDRQ pin. The DMA will empty
or fill the FIFO using the appropriate direction
and mode. When the terminal count in the DMA
controller is reached, an interrupt is generated
and serviceIntr is asserted, disabling DMA. In
order to prevent possible blocking of refresh
requests dReq shall not be asserted for more
than 32 DMA cycles in a row. The FIFO is
enabled directly by asserting nPDACK and
addresses need not be valid. PINTR is
generated when a TC is received. PDRQ must
not be asserted for more than 32 DMA cycles in
a row. After the 32nd cycle, PDRQ must be
kept unasserted until nPDACK is deasserted for
a minimum of 350nsec. (Note: The only way to
properly terminate DMA transfers is with a TC.)
(Note: In the reverse mode, the peripheral may
not continue to fill the FIFO if it runs out of data
to transfer, even if the chip continues to request
more data from the peripheral.)
The ECP activates the PDRQ pin whenever
there is data in the FIFO. The DMA controller
must respond to the request by reading data
from the FIFO. The ECP will deactivate the
PDRQ pin when the FIFO becomes empty or
when the TC becomes true (qualified by
nPDACK), indicating that no more data is
required. PDRQ goes inactive after nPDACK
goes active for the last byte of a data transfer
(or on the active edge of nIOR, on the last byte,
if no edge is present on nPDACK). If PDRQ
goes inactive due to the FIFO going empty, then
PDRQ is active again as soon as there is one
byte in the FIFO. If PDRQ goes inactive due to
the TC, then PDRQ is active again when there
is one byte in the FIFO, and serviceIntr has
been re-enabled. (Note: A data underrun may
occur if PDRQ is not removed in time to prevent
an unwanted cycle.)
DMA may be disabled in the middle of a transfer
by first disabling the host DMA controller. Then
setting serviceIntr to 1, followed by setting
dmaEn to 0, and waiting for the FIFO to
become empty or full. Restarting the DMA is
accomplished by enabling DMA in the host,
setting dmaEn to 1, followed by setting
serviceIntr to 0.
Programmed I/O Mode or Non-DMA Mode
The ECP or parallel port FIFOs may also be
operated using interrupt driven programmed I/O.
Software can determine the writeIntrThreshold,
readIntrThreshold, and FIFO depth by accessing
the FIFO in Test Mode.
Programmed I/O transfers are to the ecpDFifo
at 400H and ecpAFifo at 000H or from the
ecpDFifo located at 400H, or to/from the tFifo at
400H. To use the programmed I/O transfers,
the host first sets up the direction and state, sets
dmaEn to 0 and serviceIntr to 0.
107
The ECP requests programmed I/O transfers
from the host by activating the PINTR pin. The
programmed I/O will empty or fill the FIFO using
the appropriate direction and mode.
the FIFO. If at this time the FIFO is full, it can
be completely emptied in a single burst,
otherwise a minimum of (16-<threshold>) bytes
may be read from the FIFO in a single burst.
Note: A threshold of 16 is equivalent to a
threshold of 15. These two cases are treated
the same.
Programmed I/O - Transfers from the Host to
the FIFO
In the forward direction an interrupt occurs when
serviceIntr is 0 and there are writeIntrThreshold
or more bytes free in the FIFO. At this time if
the FIFO is empty it can be filled with a single
burst before the empty bit needs to be re-read.
Otherwise
it
may
be
filled
with
writeIntrThreshold bytes.
Programmed I/O - Transfers from the FIFO to
the Host
In the reverse direction an interrupt occurs when
serviceIntr is 0 and readIntrThreshold bytes
are available in the FIFO. If at this time the
FIFO is full it can be emptied completely in a
single burst, otherwise readIntrThreshold bytes
may be read from the FIFO in a single burst.
readIntrThreshold
writeIntrThreshold = (16-<threshold>) free
bytes in FIFO
An interrupt is generated when serviceIntr is 0
and the number of bytes in the FIFO is less than
or equal to <threshold>. (If the threshold = 12,
then the interrupt is set whenever there are 12 or
less bytes of data in the FIFO.) The PINT pin
can be used for interrupt-driven systems. The
host must respond to the request by writing data
to the FIFO. If at this time the FIFO is empty, it
can be completely filled in a single burst,
otherwise a minimum of (16-<threshold>) bytes
may be written to the FIFO in a single burst.
This process is repeated until the last byte is
transferred into the FIFO.
= (16-<threshold>)
data bytes in FIFO
An interrupt is generated when serviceIntr is 0
and the number of bytes in the FIFO is greater
than or equal to (16-<threshold>). (If the
threshold = 12, then the interrupt is set
whenever there are 4-16 bytes in the FIFO). The
PINT pin can be used for interrupt-driven
systems. The host must respond to the request
by reading data from the FIFO. This process is
repeated until the last byte is transferred out of
108
PARALLEL PORT FLOPPY DISK CONTROLLER
In this mode, the Floppy Disk Control signals
are available on the parallel port pins. When
this mode is selected, the parallel port is not
available. There are two modes of operation,
PPFD1 and PPFD2. These modes can be
selected in the Parallel Port Mode Register, as
defined in the Parallel Port Mode Register,
Logical Device 3, at 0xF1. PPFD1 has only
drive 1 on the parallel port pins; PPFD2 has
drive 0 and 1 on the parallel port pins.
The following parallel port pins are read as
follows by a read of the parallel port register:
When the PPFDC is selected the following pins
are set as follows:
The following FDC pins are all in the high
impedence state when the PPFDC is actually
selected by the drive select register:
1.
2.
3.
1.
2.
3.
nPDACK: high-Z
PDRQ: not ECP = high-Z, ECP & dmaEn =
0, ECP & not dmaEn = high-Z
PINTR: not active, this is hi-Z or Low
depending on settings.
Note:
1.
2.
nPDACK, PDRQ and PINTR refer to
the nDACK, DRQ and IRQ chosen
for the parallel port.
Data Register (read) = last Data Register
(write)
Control Register read as "cable not
connected" STROBE, AUTOFD and SLC =
0 and nINIT =1
Status Register reads: nBUSY = 0, PE = 0,
SLCT = 0, nACK = 1, nERR = 1.
nWDATA, DENSEL, nHDSEL, nWGATE,
nDIR, nSTEP, nDS1, nDS0, nMTR0,
nMTR1.
If PPFDx is selected, then the parallel port
can not be used as a parallel port until
"Normal" mode is selected.
The FDC signals are muxed onto the Parallel
Port pins as shown in Table 43.
109
Table 43 - FDC Parallel Port Pins
CONNECTOR
PIN #
CHIP PIN #
SPP MODE
PIN DIRECTION
FDC MODE
1
144
nSTB
I/O
(nDS0)
2
138
PD0
I/O
nINDEX
I
3
137
PD1
I/O
nTRK0
I
4
136
PD2
I/O
nWP
I
5
135
PD3
I/O
nRDATA
I
6
134
PD4
I/O
nDSKCHG
I
7
133
PD5
I/O
nMEDIA_ID0
I
8
132
PD6
I/O
(nMTR0)
9
131
PD7
I/O
MEDIA_ID1
I
10
129
nACK
I
nDS1
O
11
128
BUSY
I
nMTR1
O
12
127
PE
I
nWDATA
O
13
126
SLCT
I
nWGATE
O
14
143
nALF
I/O
DRVDEN0
O
15
142
nERROR
I
nHDSEL
O
16
141
nINIT
I/O
nDIR
O
17
140
nSLCTIN
I/O
nSTEP
O
Note 1: These pins are outputs in mode PPFD2, inputs in mode PPFD1.
110
PIN DIRECTION
I/(O) (Note1)
I/(O) (Note1)
AUTO POWER MANAGEMENT
Power management capabilities are provided for
the following logical devices: floppy disk, UART
1, UART 2 and the parallel port. For each
logical device, two types of power management
are provided; direct powerdown and auto
powerdown.
DSR From Powerdown
If DSR powerdown is used when the part is in
auto powerdown, the DSR powerdown will
override the auto powerdown. However, when
the part is awakened from DSR powerdown, the
auto powerdown will once again become
effective.
FDC Power Management
Direct power management is controlled by
CR22. Refer to CR22 for more information.
Wake Up From Auto Powerdown
If the part enters the powerdown state through
the auto powerdown mode, then the part can be
awakened by reset or by appropriate access to
certain registers.
Auto Power Management is enabled by CR23B0. When set, this bit allows FDC to enter
powerdown when all of the following conditions
have been met:
1.
2.
3.
4.
If a hardware or software reset is used then the
part will go through the normal reset sequence.
If the access is through the selected registers,
then the FDC resumes operation as though it
was never in powerdown. Besides activating the
RESET pin or one of the software reset bits in
the DOR or DSR, the following register
accesses will wake up the part:
The motor enable pins of register 3F2H are
inactive (zero).
The part must be idle; MSR=80H and INT =
0 (INT may be high even if MSR = 80H due
to polling interrupts).
The head unload timer must have expired.
The auto powerdown timer (10msec) must
have timed out.
1.
An internal timer is initiated as soon as the auto
powerdown command is enabled. The part is
then powered down when all the conditions are
met.
2.
3.
Disabling the auto powerdown mode cancels the
timer and holds the FDC block out of auto
powerdown.
Enabling any one of the motor enable bits
in the DOR register (reading the DOR does
not awaken the part).
A read from the MSR register.
A read or write to the data register.
Once awake, the FDC will reinitiate the auto
powerdown timer for 10 ms. The part will
powerdown again when all the powerdown
conditions are satisfied.
111
Register Behavior
Pin Behavior
Table 44 reiterates the AT and PS/2 (including
Model 30) configuration registers available. It
also shows the type of access permitted. In
order to maintain software transparency, access
to all the registers must be maintained. As Table
44 shows, two sets of registers are distinguished
based on whether their access results in the part
remaining in powerdown state or exiting it.
The FDC37C93xAPM is specifically designed for
portable PC systems in which power
conservation is a primary concern. This makes
the behavior of the pins during powerdown very
important.
The pins of the FDC37C93xAPM can be divided
into two major categories: system interface and
floppy disk drive interface. The floppy disk drive
pins are disabled so that no power will be drawn
through the part as a result of any voltage
applied to the pin within the part's power supply
range. Most of the system interface pins are left
active to monitor system accesses that may
wake up the part.
Access to all other registers is possible without
awakening the part. These registers can be
accessed during powerdown without changing
the status of the part. A read from these
registers will reflect the true status as shown in
the register description in the FDC description.
A write to the part will result in the part retaining
the data and subsequently reflecting it when the
part awakens.
Accessing the part during
powerdown may cause an increase in the power
consumption by the part. The part will revert
back to its low power mode when the access
has been completed.
System Interface Pins
Table 45 gives the state of the system interface
pins in the powerdown state. Pins unaffected by
the powerdown are labeled "Unchanged". Input
pins are "Disabled" to prevent them from
causing
currents
internal
to
the
FDC37C93xAPM when they have indeterminate
input values.
112
Table 44 - PC/AT and PS/2 Available Registers
Available Registers
Base + Address
PC-AT
PS/2 (Model 30)
Access Permitted
Access to these registers DOES NOT wake up the part
00H
----
SRA
R
01H
----
SRB
R
02H
DOR (1)
DOR (1)
R/W
03H
---
---
---
04H
DSR (1)
DSR (1)
W
06H
---
---
---
07H
DIR
DIR
R
CCR
CCR
W
07H
Access to these registers wakes up the part
04H
MSR
MSR
R
05H
Data
Data
R/W
Note 1: Writing to the DOR or DSR does not wake up the part, however, writing any of the
motor enable bits or doing a software reset (via DOR or DSR reset bits) will wake up the part.
Table 45 - State of System Pins in Auto Powerdown
SYSTEM PINS
STATE IN AUTO POWERDOWN
Input Pins
IOR
Unchanged
IOW
Unchanged
A[0:9]
Unchanged
D[0:7]
Unchanged
RESET
Unchanged
IDENT
Unchanged
DACKx
Unchanged
TC
Unchanged
Output Pins
IRQx
Unchanged (low)
DB[0:7]
Unchanged
DRQx
Unchanged (low)
113
FDD Interface Pins
Pins used for local logic control or part
programming are unaffected. Table 46 depicts
the state of the floppy disk drive interface pins in
the powerdown state.
All pins in the FDD interface which can be
connected directly to the floppy disk drive itself
are either DISABLED or TRISTATED.
Table 46 - State of Floppy Disk Drive Interface Pins in Powerdown
FDD PINS
STATE IN AUTO POWERDOWN
Input Pins
RDATA
Input
WP
Input
TRK0
Input
INDX
Input
DRV2
Input
DSKCHG
Input
Output Pins
MOTEN[0:3]
Tristated
DS[0:3]
Tristated
DIR
Active
STEP
Active
WRDATA
Tristated
WE
Tristated
HDSEL
Active
DENSEL
Active
DRATE[0:1]
Active
114
UART Power Management
Parallel Port
Direct power management is controlled by
CR22. Refer to CR22 for more information.
Direct power management is controlled by
CR22. Refer to CR22 for more information.
Auto Power Management is enabled by CR23B4 and B5. When set, these bits allow the
following auto power management operations:
Auto power management is enabled by CR23B3. When set, this bit allows the ECP or EPP
logical parallel port blocks to be placed into
powerdown when not being used.
1.
2.
The transmitter enters auto powerdown
when the transmit buffer and shift register
are empty.
The receiver enters powerdown when the
following conditions are all met:
A. Receive FIFO is empty
B. The receiver is waiting for a start bit.
The EPP logic is in powerdown under any of the
following conditions:
1.
2.
EPP is not enabled in the configuration
registers.
EPP is not selected through ecr while in
ECP mode.
Note: While in powerdown the Ring Indicator
interrupt is still valid and transitions when the
RI input changes.
The ECP logic is in powerdown under any of the
following conditions:
Exit Auto Powerdown
1.
The transmitter exits powerdown on a write to
the XMIT buffer.
The receiver exits auto
powerdown when RXDx changes state.
2
ECP is not enabled in the configuration
registers.
SPP, PS/2 Parallel port or EPP mode is
selected through ecr while in ECP mode.
Exit Auto Powerdown
The parallel port logic can change powerdown
modes when the ECP mode is changed through
the ecr register or when the parallel port mode is
changed through the configuration registers.
115
INTEGRATED DRIVE ELECTRONICS INTERFACE
The FDC37C93xAPM contains two IDE
interfaces. This enables hard disks with
embedded controllers (AT or IDE) to be
interfaced to the host processor.
The IDE
interface performs the address decoding for the
IDE interface, generates the buffer enables for
external buffers and provides internal buffers for
the low byte IDE data transfers. For more
information, refer to the IDE pin descriptions
and the ATA specification.
The following
example uses IDE1 base1=1F0H, base2=3F6H
and IDE2 base1=170H, base2 =376H.
the AT Task File, and the Miscellaneous AT
Register.
HOST FILE REGISTERS
These AT registers may be used by the BIOS for
drive control. They are accessed by the AT
interface when nHCS1 or nHCS3 is active low.
ADDRESS 1F0H-1F7H; 170H-177H
These AT registers contain the Task File
Registers. These registers communicate data,
command, and status information with the AT
host, and are addressed when nHCS0 or nHCS2
is low.
ADDRESS 3F6H/376H;
The Host File Registers are accessed by the AT
Host.
There are two groups of registers,
HOST PROCESSOR REGISTER ADDRESS MAP (AT MODE)
PRIMARY
SECONDARY
1F0H
170H
|
|
1F7H
177H
3F6H
376H
TASK FILE REGISTERS
MISC AT REGISTERS
and EATA specifications. These are available
from:
TASK FILE REGISTERS
Task File Registers may be accessed by the
host AT when pin nHDCS0 is active (low). The
Data Register (1F0H) is 16 bits wide; the
remaining task file registers are 8 bits wide. The
task file registers are
ATA
and EATA
compatible.
Please refer to the ATA
Global Engineering
2805 McGaw Street
Irvine, CA 92714
(800) 854-7179 or
(714) 261-1455
116
IDE OUTPUT ENABLES
Two IDE output Enables are available. The IDE output enables treat all IDE transfers as 16 bit
transfers.
Note 1:
Note 2:
Note 3:
nIDE1_OE
nIDE2_OE
Option 1
IDE1 (1)
IDE2 (2)
Option 2
IDE1&IDE2 (3)
(Not used)
The low and high byte transfers for IDE1 goes through external buffers controlled by
IDE1_OE. (Refer to Option 1)
The low and high byte transfers for IDE2 goes through external buffers controlled by
IDE2_OE. (Refer to Option 1)
The low and high byte transfers of IDE1 and IDE2 go through one set of external buffers
controlled by IDE1. (Refer to Option 2)
configured to support IDE drives, can be
programmed as general purpose address
decoders. Refer to the Configuration Register
Section, Logical Device 1, CRF0 and CRF1.
HDCS0 and HDCS1 of IDE1 as General
Purpose Address Decoders
HDCS0
and
HDCS1
of
IDE1,
initially
117
BIOS BUFFER
This function allows data transmission from the
RD bus to the SD bus or from the SD bus to the
RD bus.
The direction of the transfer is
controlled by nROMDIR. The enable input,
nROMCS, can be used to disable the transfer
and isolate the buses.
The FDC37C93xAPM contains one 245 type
buffer that can be used for a BIOS Buffer. If the
BIOS buffer is not used, then nROMCS and
nROMDIR must be tied high so as not to
interfere with the boot ROM.
nROMCS
nROMDIR
L
L
RD[0:7] data to SD[0:7] bus
L
H
SD[0:7] data to RD[0:7]
H
X
Isolation
SD[15:8]
IDE Channel 1
FDC37C93xAPM
SD[7:0]
IDE1_OE
B1
BIOS
Option 1
IDE2_OE
IDE Channel 2
FIGURE 2 - IDE OUTPUT ENABLE OPTION 1
118
SD[15:8]
IDE Channel 1
FDC37C93xAPM
SD[7:0]
IDE1_OE
B1
BIOS
IDE2_OE
Option 2
NC
IDE Channel 2
FIGURE 3 - IDE OUTPUT ENABLE OPTION 2
119
floats - cannot use as a bus. Any pin can be
programmed as an alternate function.
RD Bus Functionality
The following four cases described below
illustrate the use of the RD Bus.
Case 4: nROMCS and nROMOE as alternate
function. Same as Case 3.
Case 1: nROMCS and nROMOE as original
function. The RD bus can be used as the RD
bus or one or more RD pins can be
programmed as alternate function.
These
alternate functions behave as follows: if in RD to
SD mode, any value on RDx will appear on SDx;
if in SD to RD mode, SDx will not appear on
RDx, RDx gets the alternate function value.
Note: In this case, nROMCS=0, nROMOE=1.
8042 Functions
The second alternate function for pins 113-118
are the 8042 functions P12-P17. These are
implemented as in a true 8042 part. Reference
the 8042 specification for all timing. A port
signal of 0 drives the output to 0. A port signal
of 1 causes the port enable signal to drive the
output to 1 within 20-30nsec. After several (#
TBD) clocks, the port enable goes away and the
internal 90µA pull-up maintains the output signal
as 1.
Case 2: nROMOE as alternate function
(nROMOE internally tied to ground). In this
case, the RD bus is a unidirectional bus (read
only) controlled by nROMCS. If nROMCS = 0,
the values on RD0-7 appear on SD0-7. If
nROMCS = 1, the RD bus is disabled and
nothing appears on the SD bus. Note: any RD
bus pin can be programmed as an alternate
function, however, if nROMCS=0, then anything
on the RD bus will appear on the SD bus.
In 8042 mode, the pins can be programmed as
open drain. When programmed in open drain
mode, the port enables do not come into play. If
the port signal is 0 the output will be 0. If the
port signal is 1, the output tristates: an external
pull-up can pull the pin high, and the pin can be
shared i.e., P12 and nSMI can be externally tied
together. In 8042 mode, the pins cannot be
programmed as input nor inverted through the
GP configuration registers.
Case 3: nROMCS as alternate function
(nROMCS internally tied to VDD). The RD bus
120
GENERAL PURPOSE I/O FUNCTIONAL DESCRIPTION
The FDC37C93xAPM provides a set of flexible
Input/Output control functions to the system
designer through a set of General Purpose I/O
pins (GPI/O). These GPI/O pins may perform
simple I/O or may be individually configured to
provide a predefined alternate function. Poweron reset configures all GPI/O pins as simple
non-inverting inputs.
Pin
Number
96
General Purpose I/O Ports
The FDC37C93xAPM has 14 dedicated,
independently-programmable general purpose
I/O ports (GPI/O).
Each GPI/O port is
represented as a bit in one of two GPI/O 8-bit
registers, GP1 or GP2. Only 6 bits of GP2 are
implemented. Each GPI/O port and its alternate
function is listed in Table 47A.
Table 47A - General Purpose I/O Port Assignments
Original
Alternate
Alternate
Alternate
Function
Function 1
Function 2
Function 3
GP10
Interrupt Steering*
-
Register
Assignment
GP1, bit 0
97
GP11
Interrupt Steering*
IRQ 13
-
GP1, bit 1
98
GP12
WD Timer Output
IRRX Input
-
GP1, bit 2
99
GP13
Power LED
IRTX Output
-
GP1, bit 3
100
GP14
GP Address
Decoder
-
-
GP1, bit 4
102
GP15
GP Write Strobe
-
-
GP1, bit 5
103
GP16
Joystick RD Strobe
Joystick Chip Sel
-
GP1, bit 6
104
GP17
Joystick WR
Strobe
-
-
GP1, bit 7
105
GP20
IDE2 Buffer Enable
8042 P20
-
GP2, bit 0
106
GP21
Serial EEPROM
Data In *
AB_DATA
-
GP2, bit 1
107
GP22
Serial EEPROM
Data Out
AB_CLK
-
GP2, bit 2
108
GP23
Serial EEPROM
Clock
-
-
GP2, bit 3
109
GP24
Serial EEPROM
Enable
-
-
GP2, bit 4
110
GP25
8042 P21
GP2, bit 5
Note 1: 8042 P21 is normally used for Gate A20
Note 2: 8042 P20 is normally used for the Keyboard Reset Output
* These are input-type alternate functions; all other GPI/O pins contain output-type alternate
functions.
121
The FDC37C93xAPM also has 28 GPI/O ports
that are the first alternate functions of pins
with other default functions.
listed in Table 47B below.
These pins are
Table 47B - Multifunction GPI/O Pins
PIN
NUMBER
19
ORIGINAL
FUNCTION
MEDIA_ID1
ALTERNATE
FUNCTION 1
GP40
ALTERNATE
FUNCTION 2
-
ALTERNATE
FUNCTION 3
-
GPI/O
REGISTER
ASSIGNMENT
GP4, bit 0
20
MEDIA_ID0
GP41
-
-
GP4, bit 1
23
nIDE1_OE
GP42
-
-
GP4, bit 2
24
nHDCS0
GP43
-
-
GP4, bit 3
25
nHDCS1
GP44
-
-
GP4, bit 4
26
IDE1_IRQ
GP45
-
-
GP4, bit 5
30
nIOROP
GP46
WDT
GP4, bit 6
31
nIOWOP
GP47
Power LED
Output
nSMI
-
GP4, bit 7
33
nPowerOn
GP51
-
-
GP5, bit 1
34
Button_In
GP50
-
-
GP5, bit 0
111
RD0 (1) (3)
GP60
-
GP6, bit 0
112
RD1 (1) (3)
GP61
Power LED
Output
WDT
-
GP6, bit 1
113
RD2 (1) (3)
GP62
8042 - P12
-
GP6, bit 2
114
RD3 (1) (3)
GP63
8042 - P13
-
GP6, bit 3
115
RD4 (1) (3)
GP64
8042 - P14
-
GP6, bit 4
116
RD5 (1) (3)
GP65
8042 - P15
-
GP6, bit 5
117
RD6 (1) (3)
GP66
8042 - P16
-
GP6, bit 6
118
RD7 (1) (3)
GP67
8042 - P17
-
GP6, bit 7
119
nROMCS (1)
GP53
-
-
GP5, bit 3
120
nROMOE (1)
GP54
-
-
GP5, bit 4
153
nRI2 (2)
GP70
-
-
GP7, bit 0
154
nDCD2 (2)
GP71
-
-
GP7, bit 1
155
RXD2 (2)
GP72
-
-
GP7, bit 2
156
TXD2 (2) (3)
GP73
-
-
GP7, bit 3
122
PIN
NUMBER
157
158
159
160
ORIGINAL
FUNCTION
nDSR2 (2)
nRTS2 (2)
(3)
nCTS2 (2)
nDTR2 (2)
(3)
ALTERNATE
FUNCTION 1
GP74
ALTERNATE
FUNCTION 2
-
ALTERNATE
FUNCTION 3
-
GPI/O
REGISTER
ASSIGNMENT
GP7, bit 4
GP75
-
-
GP7, bit 5
GP76
-
-
GP7, bit 6
GP77
-
-
GP7, bit 7
Note 1: At power-up, RD0-RD7, nROMCS and nROMOE function as the XD Bus. To use RD0RD7 for functions other than the XD Bus, nROMCS must stay high until those pins are
finished being reprogrammed.
Note 2: These pins are input (high-z) until programmed for second serial port.
Note 3: These pins cannot be programmed as open drain pins in their original function.
Note 4: No pins in their original function can be programmed as inverted input or inverted output.
To access the GP1 register when in normal
(run) mode, the host should perform an IOW of
0x01 to the Index register (at 0xEX) to select
GP1 and then read or write the Data register (at
Index+1) to access the GP1 register. To access
GP2 the host should perform an IOW of 0x02 to
the Index register and then access GP2 through
the Data register. GP4-7 and the Soft Power
and SMI Registers are acessed similarly.
Additionally the host can access the
WDT_CTRL (Watch Dog Timer Control)
Configuration Register while in the normal (run)
mode by writing an 0x03 to the index register.
GPI/O registers GP1 through GP7 as well as the
Soft Power and SMI Enable and Status
Registers can be accessed by the host when the
chip is in the normal run mode if CR03 Bit[7]=1.
The host uses an Index and Data register to
access these registers. The Power on default
Index and Data registers are 0xEA and 0xEB
respectively. In configuration mode the Index
address may be programmed to reside on
addresses 0xE0, 0xE2, 0xE4 or 0xEA. The Data
address is automatically set to the Index
address + 1. Upon exiting the configuration
mode the new Index and Data registers are used
to access registers GP1 through GP7 and Soft
Power and SMI Enable and Status Registers.
The GP registers can also be accessed by the
host when in configuration mode through CRF6FB of Logical Device 8.
123
REGISTER
Table 48A - Index and Data Register
ADDRESS
NORMAL (RUN) MODE
Index
0xE0, E2, E4, EA
0x01-0x0F
Data
Index address + 1
Access to GP1, GP2,
Watchdog Timer Control,
GP4, GP5, GP6, GP7, Soft
Power and SMI Enable and
Status Registers (see
Table 48B)
Table 48B - Index and Data Register Normal (Run) Mode
INDEX
NORMAL (RUN) MODE
0x01
Access to GP1 (L8 - CRF6)
0x02
Access to GP2 (L8 - CRF7)
0x03
Access to Watchdog Timer Control (L8 - CRF4)
0x04
Access to GP4 (L8 - CRF8)
0x05
Access to GP5 (L8 - CRF9)
0x06
Access to GP6 (L8 - CRFA)
0x07
Access to GP7 (L8 - CRFB)
0x08
Access to Soft Power Enable Register 1 (L8-CRB0)
0x09
Access to Soft Power Enable Register 2 (L8-CRB1)
0x0A
Access to Soft Power Status Register 1 (L8-CRB2)
0x0B
Access to Soft Power Status Register 2 (L8-CRB3)
0x0C
Access to SMI Enable Register 1 (L8-CRB4)
0x0D
Access to SMI Enable Register 2 (L8-CRB5)
0x0E
Access to SMI Status Register 1 (L8-CRB6)
0x0F
Access to SMI Status Register 2 (L8-CRB7)
Note 1: These registers can also be accessed through the configuration registers at L8 CRxx shown in the table above.
124
GPI/O ports contain alternate functions which
are either output-type or input-type. The GPI/O
port structure
for each type is illustrated
in the following two figures. Note: the input pin
buffer is always enabled.
GPI/O
Configuration
Register bit-1
(Polarity)
GPI/O
Configuration
Register bit-0
(Input/Output)
SD-bit
D-TYPE
nIOW
GPI/O
Pin
0
nIOR
Transparent
GPI/O
Register
Bit-n
1
1
0
GPI/O
Configuration
Register bit-2
(Int En)
GPIO
Configuration
Register bit-3
(Alt Function)
Alternate
Input
Function
To GP Interrupt
FIGURE 4 - GPI/O HAVING AN INPUT-TYPE ALTERNATE FUNCTION [GP10, GP11, GP12, GP21]
125
GPIO
Configuration
Register bit-3
(Alt Function)
GPI/O
Configuration
Register bit-0
(Input/Output)
GPI/O
Configuration
Register bit-1
(Polarity)
Alternate
Output
Function
1
SD-bit
nIOW
0
D-TYPE
GPI/O
Pin
0
nIOR
Transparent
1
1
GPI/O
Register
Bit-n
0
GPI/O
Configuration
Register bit-2
(Int En)
To GP Interrupt
FIGURE 5 - GPI/O HAVING AN OUTPUT-TYPE ALTERNATE FUNCTION [GP12 - GP17, GP20,
GP22 - GP25]
126
Assigned to each GPI/O port is an 8-bit GPI/O
Configuration Register which is used to
independently program each I/O port. The
GPI/O Configuration Registers are only
accessible when the FDC37C93xAPM is in the
Configuration Mode; more information can be
found in the Configuration section of this
specification.
In addition, the GPI/O port may be optionally
programmed to steer its signal to a Combined
General Purpose Interrupt request output pin on
the FDC37C93xAPM. The interrupt channel for
the Combined Interrupt is selected by the
GP_INT Configuration Register defined in the
FDC37C93xAPM System Configuration Section.
The Combined Interrupt is the "ORed" function
of the interrupt enabled GPI/O ports and will
represent a standard ISA interrupt (edge high).
Each GPI/O port may be programmed as either
a simple inverting or non-inverting input or
output port, or as an alternate function port. The
least-significant four bits of each GPI/O
Configuration Register define the operation of
the respective GPI/O port. The basic GPI/O
operations are outlined in Table 49.
When programmed as an input steered onto
the General Purpose Combined Interrupt (GP
IRQ), the Interrupt Circuitry contains a
selectable debounce/digital filter circuit in
order that switches or push-buttons may be
directly connected to the chip. This filter will
reject signals with pulse widths of 1ms or less.
General Purpose I/O Configuration Registers
Table 49 - GPI/O Configuration Register Bits [3:0]
ALT FUNC
BIT 3
0=
DISABLE
1=SELECT
INT EN
BIT 2
0=DISABLE
1=ENABLE
POLARITY
BIT 1
0=
NO INVERT
1=INVERT
I/O
BIT 0
1=INPUT
0=OUTPUT
0
0
0
0
simple non-inverting output
0
0
0
1
simple non-inverting input
0
0
1
0
simple inverting output
0
0
1
1
simple inverting input
0
1
0
0
non-inverting output steered back to GP
IRQ
0
1
0
1
non-inverting input steered to GP IRQ
0
1
1
0
inverting output steered back to GP IRQ
0
1
1
1
inverting input steered to GP IRQ
1
0
0
0
Alternate Function Output-type:
Alternate non-inverted output.
Alternate Function Input-type:
Alternate function not valid, GPI/O pin
acts as a simple non-inverting output.
127
GPI/O PORT
OPERATION
Table 49 - GPI/O Configuration Register Bits [3:0]
ALT FUNC
BIT 3
0=
DISABLE
1=SELECT
INT EN
BIT 2
0=DISABLE
1=ENABLE
POLARITY
BIT 1
0=
NO INVERT
1=INVERT
I/O
BIT 0
1=INPUT
0=OUTPUT
1
0
0
1
Alternate Function Output-type:
Alternate function not valid, GPI/O pin
acts as a simple non-inverting input.
Alternate Function Input-type:
Alternate non-inverting input.
1
0
1
0
Alternate Function Output-type:
Alternate output function with inverted
sense
Alternate Function Input-type:
Alternate function not valid, GPI/O pin
acts as a simple inverting output.
1
0
1
1
Alternate Function Output-type:
Alternate output function not valid,
GPI/O pin acts as a simple inverting
input.
Alternate Function Input-type:
Inverting input to alternate input
function.
1
1
0
0
Alternate Function Output-type:
Alternate output function with non
inverted sense steered to GP IRQ
Alternate Function Input-type:
Alternate function not valid, GPI/O pin
acts as a simple non-inverting output
steered to GP IRQ
1
1
0
1
Alternate Function Output-Type:
Alternate output function not valid,
GPI/O pin acts as a simple non-inverting
input steered to GP IRQ.
Alternate Function Input-type:
Non-inverting input to alternate input
function also steered to the GP IRQ.
128
GPI/O PORT
OPERATION
Table 49 - GPI/O Configuration Register Bits [3:0]
ALT FUNC
BIT 3
0=
DISABLE
1=SELECT
INT EN
BIT 2
0=DISABLE
1=ENABLE
POLARITY
BIT 1
0=
NO INVERT
1=INVERT
I/O
BIT 0
1=INPUT
0=OUTPUT
1
1
1
0
Alternate Function Output-type:
Alternate output function with inverted
sense steered to GP IRQ
Alternate Function Inputtype:Alternate function not valid, GPI/O
pin acts as a simple inverting output
steered to GP IRQ.
1
1
1
1
Alternate Function Output-type:
Alternate output function not valid,
GPI/O pin acts as a simple inverting
input steered to GP IRQ.
Alternate Function Input-type:
Inverting input to alternate input function
also steered to the GP IRQ.
The alternate function of GP10 and GP11 allows
these GPI/O port pins to be mapped to their own
independent interrupt channels.
The upper
nibble of the GP10 and
GP11 GPI/O
GPI/O PORT
OPERATION
configuration registers is used to select the
active interrupt channel for each of these ports
as shown in the Configuration section of this
specification.
129
effect. When a GPI/O port is programmed as
an output, the logic value written into the GPI/O
register is either output to or inverted to the
GPI/O pin; when read the result will reflect the
contents of the GPI/O register bit. This is
summarized in Table 50.
Reading and Writing GPI/O Ports
When a GPI/O port is programmed as an input,
reading it through the GPI/O register latches
either the inverted or non-inverted logic value
present at the GPI/O pin; writing it has no
HOST OPERATION
Table 50 - GPI/O Read/Write Behavior
GPI/O INPUT PORT
GPI/O OUTPUT PORT
Read
Latched Value of GPI/O Pin
Bit Value In GP Register
Write
No Effect
Bit Placed In GP Register
WATCH DOG TIMER/POWER LED CONTROL
Configuration Registers is set "and" bit 6 of the
IR Options Register is set.
BASIC FUNCTIONS
The FDC37C93xAPM contains a Watch Dog
Timer (WDT) and also has the capability to
directly drive the system's Power-on LED.
Pins 30 (nIOROP/GP46) and 111 (RD0/GP60)
can also be configured for Power LED.
WATCH DOG TIMER
The Watch Dog Time-Out status bit
(WDT_CTRL bit 0) is mapped to GP12 when the
alternate function bit of the GP12 Configuration
Register is set "and" bit 6 of the IR Options
Register = 0. In addition, the Watch Dog Timeout status bit may be mapped to an interrupt
through the WDT_CFG Configuration Register.
The
FDC37C93xAPM's
WDT
has
a
programmable time-out ranging from one to 255
minutes with one minute resolution, or one to
255 seconds with one second resolution. The
units of the WDT timeout value are selected via
bit 7 of the GPA_GPW_EN register (located at
0xF1 of Logical Device 8). The WDT time-out
value
is
set
through
the
WDT_VAL
Configuration register. Setting the WDT_VAL
register to 0x00 disables the WDT function (this
is its power on default). Setting the WDT_VAL
to any other non-zero value will cause the WDT
to reload and begin counting down from the
value loaded. When the WDT count value
reaches zero the counter stops and sets the
Watchdog time-out status bit in the WDT_CTRL
Configuration Register. Note: Regardless of the
current state of the WDT, the WDT time-out
status bit can be directly set or cleared by the
Host CPU.
Pins 30 (nIOROP/GP46) and 112 (RD1/GP61)
can also be configured for WDT.
GP13 may be configured as a high current LED
driver to drive the power LED.
This is
accomplished by setting the alternate function
bit of the GP13 Configuration Register "and"
clearing bit 6 of the IR Options Register.
The infared signals, IRRX and IRTX, are
mapped to GP12 and GP13 when the alternate
function bit of the GP12 and GP13
130
The host may force a Watch Dog time-out to
occur by writing a "1" to bit 2 of the WDT_CTRL
(Force WD Time-out) Configuration Register.
Writing a "1" to this bit forces the WDT count
value to zero and sets bit 0 of the WDT_CTRL
(Watch Dog Status). Bit 2 of the WDT_CTRL is
self-clearing.
There are three system events which can reset
the WDT; these are a keyboard interrupt, a
mouse interrupt, or I/O reads/writes to address
0x201 (the internal or an external joystick Port).
The effect on the WDT for each of these system
events may be individually enabled or disabled
through bits in the WDT_CFG Configuration
Register. When a system event is enabled
through the WDT_CFG register, the occurence
of that event will cause the WDT to reload the
value stored in WDT_VAL and reset the WDT
time-out status bit if set. If all three system
events are disabled, the WDT will inevitably
time out.
POWER LED TOGGLE
Setting bit 1 of the WDT_CTRL Configuration
Register will cause the power LED output driver
to toggle at 1 Hertz with a 50 percent duty cycle.
When this bit is cleared the power LED output
will drive continuously unless it has been
configured to toggle on Watch Dog time-out
conditions. Setting bit 3 of the WDT_CFG
configuration register will cause the Power LED
output driver to toggle at 1 Hertz with a 50
percent duty cycle whenever the WDT time-out
status bit is set. The truth table below clarifies
the conditions for which the Power LED will
toggle.
The Watch Dog Timer may be configured to
generate an interrupt on the rising edge of the
time-out status bit.
The WDT interrupt is
mapped to an interrupt channel through the
WDT_CFG Configuration Register.
When
mapped to an interrupt the interrupt request pin
reflects the value of the WDT time-out status bit.
When the polarity bit is 0, GP12 reflect the value
of the Watch Dog Time-out status bit, however
when the polarity bit is 1, GP12 reflects the
inverted value of the Watch Dog time-out status
bit. This is also true for the other two pins used
for WDT, nIOROP (GP46) and RD1 (GP61).
WDT_CTRL BIT 1
POWER LED TOGGLE
When the polarity bit is 0, the power LED output
asserts or drives low. If the polarity bit is 1 then
the power LED output asserts or drives high.
Table 51 - LED Toggle Truth Table
WDT_CFG BIT 3
POWER LED
WDT_CTRL BIT 0
TOGGLE ON WDT
WDT T/O STATUS BIT
POWER LED STATE
1
X
X
Toggle
0
0
X
Continuous
0
1
0
Continuous
0
1
1
Toggle
131
Table 52 - Watchdog Timer/Power LED Configuration Registers
CONFIG REG.
BIT FIELD
DESCRIPTION
WDT_VAL
Bits[7:0]
Binary coded time-out value, 0x00 disables the WDT.
WDT_CFG
Bit[0]
Joystick enable
Bit[1]
Keyboard enable
Bit[2]
Mouse enable
Bit[3]
Power LED toggle on WDT time-out
Bits[7:4]
WDT interrupt mapping,
0000b = diables irq mapping
Bit[0]
WDT time-out status bit
Bit[1]
Power LED toggle
Bit[2]
Force Timeout, self-clearing
Bit[3]
P20 Force Timeout Enable
Bit[4]
Reserved, set to zero
Bit[5,6,7]
Stop_Cnt, Restart_Cnt, SPOFF: used for Soft power mgt
WDT_CTRL
GENERAL PURPOSE ADDRESS DECODER
GENERAL PURPOSE WRITE
General Purpose I/O pin GP14 may be
configured as a General Purpose Address
Decode Pin. The General Purpose Address
Decoder provides an output decoded from bits
A11-A1 of the 12-bit address stored in a twobyte Base I/O Address Register (Logical Device
8 Configuration Registers 0x60, 0x61) qualified
with AEN. Thus, the decoder provides a two
address decode where A0=X. This General
Purpose output is normally active low, however
the polarity may be altered through the polarity
bit in its GPI/O Configuration Register.
General Purpose I/O pin GP15 may be
configured as a General Purpose Write pin. The
General Purpose Write provides an output
decoded from the 12-bit address stored in a
two-byte Base I/O Address Register (Logical
Device 8 Configuration Registers 0x62, 0x63)
qualified with IOW and AEN. This General
Purpose output is normally active low, however
the polarity may be altered through the polarity
bit in its GPI/O Configuration Register.
The GPA_GPW_EN Configuration Register
contains two bits which allow the General
Purpose Address Decode and Write functions to
be independently enabled or disabled.
The pins nHDCS0 and nHDCS1 can also be
used as general purpose address decoders. See
Configuration section, Logical Device 1, for
more information.
JOYSTICK CONTROL
The base I/O address of the Joystick (Game)
Port is fixed at address 0x201.
132
GP16 JOYSTICK FUNCTION
SERIAL EEPROM INTERFACE
The FDC37C93xAPM may be configured to
generate either a Joystick Chip Select or a
Joystick Read Strobe on GP16. The polarity is
programmable through a bit in the GP16
confiugration register. When configured as a
Joystick Chip Select the output is simply a
decode of the address = 0x201 qualified by AEN
active. When configured as a Joystick Read
Strobe the output is a decode of the address =
0x201 qualified by IOR and AEN both active.
The Joystick Chip Select or Read Strobe is
normally active low, however its polarity is
programmable through a bit in the GP20
configuration register.
Four of the FDC37C93xAPM's general purpose
I/O pins may be configured to provide a four
wire direct interface to a family of industry
standard serial EEPROMs.
For proper
operation the polarity bits of these four pins
must be set to 0 (non-inverting). The interface
is depicted below and will allow connection to
either a 93C06 (256-bit), a 93C46 (1K-bit), a
93C56 (2K-bit), or a 93C66 (4K-bit) device.
GP17 JOYSTICK FUNCTION
Reset out is an internal signal from the keyboard
controller (Port 20). The FDC37C93xAPM may
be configured to drive this signal onto GP20 by
programming its GPI/O configuration register.
GP21 <---- Serial EEPROM Data In
GP22 ----> Serial EEPROM Data Out
GP23 ----> Serial EEPROM Clock
GP24 ----> Serial EEPROM Enable
The FDC37C93xAPM may be configured to
generate a Joystick Write Strobe on GP17.
When configured as a Joystick Write Strobe the
output is a decode of the address = 0x201
qualified by IOW and AEN both active.
The Joystick Write Strobe is normally active
low, however, its polarity is programmable
through a bit in the GP20 configuration register.
Access to the serial EEPROM is only available
when the FDC37C93xAPM is in the
configuration mode. A set of six configuration
registers, located in Logical Device 6 (RTC) is
used to fully access and configure the serial
EEPROM. The registers are defined as follows:
IDE2 BUFFER ENABLE/RESET OUT
Serial EEPROM Mode Register, 0xF1
The FDC37C93xAPM may be configured to
provide an nIDE2_OE buffer enable signal on
pin GP20. The IDE2 Mode Register (0xF0 of
Logical Device 2) contains a bit which
determines whether nIDE1_OE or nIDE2_OE is
active for IDE2 transfers. If GP20 is selected
as a General Purpose I/O pin, IDE2 I/O
accesses must be configured to activate
nIDE1_OE for IDE2 transfers if a secondary
hard drive interface is present.
BIT 3 and 0
These are the lock bits which once set deny
access to the serial EEPROM's first 128 bytes in
32 byte blocks. Bit 0 locks the first block, bit 1
the second block, bit 2 the third block and bit 3
the fourth block of 32 bytes. Once these lock
bits are set they cannot be reset in any way
other than by a Hard reset or a power-on reset.
BIT 4
This selects the type of EEPROM connected to
the FDC37C93xAPM. If cleared the device must
be either a 93C06 or 93C46 and if set the device
must be either an 93C56 or 93C66. This bit
must be properly set before attempting to
access the serial EEPROM.
The polarity of nIDE2_OE, which is normally
active low, is programmable through a bit in the
GP20 configuration register.
133
When = (0,0) bit 1 is cleared on the second
write of the Write EEPROM Data register
indicating that two bytes have been accepted
and that the serial device interface is busy
writing the word to the EEPROM.
BIT 7 - 5
Reserved, set to zero.
Serial EEPROM Pointer Register, 0xF2
BIT 7 - 0
Use this register to set the Serial EEPROM's
pointer.
The value in this register always
reflects the current EEPROM pointer address.
The Serial Device Pointer increments after each
pair of reads from the Resource Data register or
after each pair of writes to the Program
Resource Data register.
BIT 6 - 2
Reserved, set to “0”
BIT 7
This bit is cleared to configure the EEPROM
interface for Read operations. Clearing this bit
enables the serial EEPROM prefetch when the
Serial EEPROM Pointer Register is updated
(written or auto-incremented).
Write EEPROM Data Register, 0xF3
This bit is set to configure the EEPROM
interface for Write operations. Setting this bit
disables the serial EEPROM prefetch when the
Serial EEPROM Pointer Register is updated
(written or auto-incremented).
BIT 7 - 0
This register allows the host to write data into
the serial EEPROM.
The FDC37C93xAPM
supports
serial
EEPROMS
with
x16
configurations. Two bytes must be written to
this register in order to generate an EEPROM
write cycle. The LSB leads the MSB. The first
write to this register resets bit 0 of the Write
Status register. The second write resets bit 1 of
the Write Status register and generates a write
cycle to the serial EEPROM. The Write Status
register must be polled before performing a pair
of writes to this register.
Read EEPROM Data Register, 0xF5
BIT 7 - 0
This register allows the host to read data from
the serial EEPROM. Data is not valid in this
register until bit 0 of the Read Status Register is
set. Since the EEPROM is a 16-bit device this
register presents the LSB followed by the MSB
for each pair of register reads. Immediately after
the MSB is read bit-0 of the Read Status
Register will be cleared, then the Serial
EEPROM Pointer Register will be autoincremented, then the next word of EEPROM
data will be fetched, followed by the Read
Status Register, bit 0 being set.
Write Status Register, 0xF4
BIT 1 and 0
When = (1,1)Indicates that the Write EEPROM
Data register is ready to accept a pair of bytes.
When = (1,0) bit 0 is cleared on the first write of
the Write EEPROM Data register. This status
indicates that the serial device controller has
received one byte (LSB) and is waiting for the
second byte (MSB).
Read Status Register, 0xF6
Bit[0]
When set, indicates that data in the Read
EEPROM Data register is valid. This bit is
cleared when EEPROM Data is read until the
next byte is valid. Reading the Read EEPROM
Data register when bit 0 is clear will have no
detremental effects; the data will simply be
invalid.
134
pin. In addition, if this function is selected, then
the bits that control in/out, polarity and open
collector/push-pull will have no effect on the
function of the pin. However, the polarity will
affect the value of the GP bit.
GATEA20
GATEA20 is an internal signal from the
Keyboard
controller
(Port
21).
The
FDC37C93xAPM may be configured to drive this
signal onto GP25 by programming its GPI/O
Configuration Register. See the 8042 Keyboard
Controller Section for more information.
An interrupt occurs if the status bit is set and the
interrupt is enabled. The status bits indicate
which of these interrupts transitioned. These
status bits are located in the MSC_STS register
(See ACPI section). These bits are cleared by a
writing a 1 to their respective bit locations
(writing a 0 has no effect). The status is valid
whether the interrupt is enabled or not and
whether or not the pin is selected for either edge
triggered interrupt.
EITHER EDGE TRIGGERED INTERRUPTS
Three GPIOs will allow an interrupt to be
generated on either a high-to-low or low-to-high
edge transition, instead of one or the other as
selected by the polarity bit. These GPIOs,
GP42, GP23, GP24, pins 23, 108, 109,
respectively, can be used to detect system
changes.
Note: These additional interrupts will go through
the same selectable debounce/digital filter
circuit as any interrupt that is steered onto one
of the GP group interrupts.
Note: These pins are enabled as interrupts by
selecting the “Either Edge Triggered Interrupt
Input x Enable” function through bits[4:3].
Selecting the “Either Edge Triggered Interrupt
Input x Enable” function for these GPI/O pins is
only applicable if the combined interrupt is
enabled (GP42 can be enabled onto either
GPINT1 or GPINT2; GP23 and GP24 can be
enabled onto GPINT1). Otherwise, selection of
this function will produce no function for the
These interrupts function as follows: when an
edge comes in, an interrupt is generated and the
status bit is set. When the interrupt is serviced,
the status bit is cleared. When the next edge
comes in, an interrupt is generated and the
status bit is set. Again, when the interrupt is
serviced, the status bit is cleared. See Figure 6
below.
GPI/O Pin
GP Interrupt
Cleared by a Write to the
Status Bit
FIGURE 6 - EITHER EDGE TRIGGERED INTERRUPT TIMING EXAMPLE
135
8042 KEYBOARD CONTROLLER AND REAL TIME CLOCK FUNCTIONAL
DESCRIPTION
The Universal Keyboard Controller uses an
8042 microcontroller CPU core. This section
concentrates
on
the
FDC37C93xAPM
enhancements to the 8042.
For general
information about the 8042, refer to the "Hardware Description of the 8042" in the 8-Bit
Embedded Controller Handbook.
The FDC37C93xAPM is a Ultra I/O, Real Time
Clock and Universal Keyboard Controller designed for intelligent keyboard management in
desktop computer applications. The Ultra I/O
supports a floppy disk controller, two 16550type serial ports, one ECP/EPP parallel port and
two IDE drive interfaces with support for four
drives.
KIRQ
MIRQ
GP25
GP20 (WD Timer)
P24
P25
P21
P20
8042A
LS05
P27
P10
P26
TST0
KDAT
P23
TST1
MCLK
P22
P11
MDAT
KCLK
FIGURE 6 - KEYBOARD AND MOUSE INTERFACE
KIRQ is the Keyboard IRQ
MIRQ is the Mouse IRQ
GP25 - Port 21 is GP25's alternate function output and can be used to create a GATEA20 signal from
the FDC37C93xAPM.
GP20 - This general purpose output can be configured as the 8042 Port 2.0 which is typically used to
create a "keyboard reset" signal. The 8042's P20 can be used to optionally reset the Watch Dog
Timer.
136
KEYBOARD AND RTC ISA INTERFACE
Input Data register, and Output Data register.
Table 53 shows how the interface decodes the
control signals. In addition to the above signals,
the host interface includes keyboard and mouse
IRQs.
The
FDC37C93xAPM
ISA
interface
is
functionally compatible with the 8042-style host
interface. It consists of the D0-7 data bus, the
nIOR, nIOW and the Status register,
Table 53 - ISA I/O Address Map
Addresses 0x60, 0x64, 0x70 and 0x71 are qualified by AEN
ISA ADDRESS (NOTE 1)
BLOCK
FUNCTION
0x70
(R/W)
RTC
Address Register
0x71
(R/W)
RTC
Data Register
Bank 0 is at 70h. Bank 1 and 2 are relocatable via the RTC Mode Register and the Secondary Base
Address for RTC Bank 1 and 2 (CR62 and CR63). See Configuration section.
ISA ADDRESS
nIOW
nIOR
BLOCK
0x60
0
1
KDATA
Keyboard Data Write (C/D=0)
1
0
KDATA
Keyboard Data Read
0
1
KDCTL
Keyboard Command Write (C/D=1)
1
0
KDCTL
Keyboard Status Read
0x64
FUNCTION*
Note*:
These registers consist of three separate 8 bit registers: Status, Data/Command Write
and Data Read.
Keyboard Data Write
Keyboard Command Write
This is an 8 bit write only register. When
written, the C/D status bit of the status register
is cleared to zero and the IBF bit is set.
This is an 8 bit write only register. When
written, the C/D status bit of the status register
is set to one and the IBF bit is set.
Keyboard Data Read
Keyboard Status Read
This is an 8 bit read only register. If enabled by
"ENABLE FLAGS", when read, the KIRQ output
is cleared and the OBF flag in the status register
is cleared. If not enabled, the KIRQ and/or
AUXOBF1 must be cleared in software.
This is an 8 bit read only register. Refer to the
description of the Status Register for more
information.
RTC Address Register
Writing to this register sets the CMOS address
that will be read or written.
137
RTC Data Register
CPU-to-Host Communication
A read of this register will read the contents of
the selected CMOS register. A write to this
register will write to the selected CMOS register.
The FDC37C93xAPM CPU can write to the Output Data register via register DBB. A write
to this register automatically sets Bit 0 (OBF) in
the Status register. See Table 54.
8042 INSTRUCTION
OUT DBB
Table 54 - Host Interface Flags
FLAG
Set OBF, and, if enabled, the KIRQ output signal goes high
If "EN FLAGS” has not been executed, KIRQ
can be controlled by writing to P24. Writing a
“0” to P24 forces KIRQ low; a high forces KIRQ
high.
Host-to-CPU Communication
The host system can send both commands and
data to the Input Data register. The CPU
differentiates between commands and data by
reading the value of Bit 3 of the Status register.
When bit 3 is "1", the CPU interprets the register
contents as a command. When bit 3 is "0", the
CPU interprets the register contents as data.
During a host write operation, bit 3 is set to "1" if
SA2 = 1 or reset to "0" if SA2 = 0.
MIRQ
If "EN FLAGS" has been executed and P25 is
set to a “1”, IBF is inverted and gated onto
MIRQ. The MIRQ signal can be connected to
system
interrupt
to
signify
that
the
FDC37C93xAPM’s CPU has read the DBB
register.
KIRQ
If "EN FLAGS” has not been executed, MIRQ is
controlled by P25, Writing a “0” to P25 forces
MIRQ low; a high forces MIRQ high. (MIRQ is
normally selected as IRQ12 for mouse support.)
If "EN FLAGS" has been executed and P24 is
set to a one: the OBF flag is gated onto KIRQ.
The KIRQ signal can be connected to system
interrupt to signify that the FDC37C93xAPM’s
CPU has written to the output data register via
"OUT DBB,A". If P24 is set to a “0”, KIRQ is
forced low. On power-up, after a valid RST
pulse has been delivered to the device, KIRQ is
reset to 0. KIRQ will normally reflects the status
of writes "DBB". (KIRQ is normally selected as
IRQ1 for keyboard support.)
Gate A20
A general purpose P21 can be routed out to the
general purpose pin GP25 for use as a
software-controlled Gate A20 or user-defined
output.
138
EXTERNAL
INTERFACE
KEYBOARD
AND
interrupt and the IBF interrupt is enabled, then
program execution resumes with a CALL to the
interrupt routine, otherwise the next instruction
is executed. If it is exited using RESET, then a
normal reset sequence is initiated and program
execution starts from program memory location
0.
MOUSE
Industry-standard PC/AT-compatible keyboards
employ a two-wire, bidirectional TTL interface
for data transmission. Several sources also
supply PS/2 mouse products that employ the
same type of interface. To facilitate system
expansion, the FDC37C93xAPM provides four
signal pins that may be used to implement this
interface directly for an external keyboard and
mouse.
Hard Powerdown Mode
This mode is entered by executing a STOP
instruction. The oscillator is stopped by
disabling the oscillator driver
cell. When
either RESET is driven active or a data byte is
written to the DBBIN register by a master
CPU, this mode will be exited (as above).
However, as the oscillator cell will require an
initialization time, either RESET must be held
active for sufficient time to allow the oscillator to
stabilise. Program execution will resume as
above.
The FDC37C93xAPM has four high-drive, opendrain output, bidirectional port pins that can be
used for external serial interfaces, such as ISA
external keyboard and PS/2-type mouse
interfaces. They are KCLK, KDAT, MCLK, and
MDAT. P26 is inverted and output as KCLK.
The KCLK pin is connected to TEST0. P27 is
inverted and output as KDAT. The KDAT pin is
connected to P10. P23 is inverted and output
as MCLK. The MCLK pin is connected to
TEST1. P22 is inverted and output as MDAT.
The MDAT pin is connected to P11. Note:
External pull-ups may be required.
INTERRUPTS
The FDC37C93xAPM provides the two 8042
interrupts, IBF and the Timer/Counter Overflow.
KEYBOARD POWER MANAGEMENT
MEMORY CONFIGURATIONS
The keyboard provides support for two powersaving modes: soft powerdown mode and hard
powerdown mode. In soft powerdown mode,
the clock to the ALU is stopped but the
timer/counter and interrupts are still active. In
hard power down mode the clock to the 8042 is
stopped.
Efforts must be made to reduce
power wherever possible!
The FDC37C93xAPM provides 2K of on-chip
ROM and 256 bytes of on-chip RAM.
REGISTER DEFINITIONS
Host I/F Data Register
The Input Data register and Output Data register
are each 8 bits wide. A write to this 8 bit register
will load the Keyboard Data Read Buffer, set the
OBF flag and set the KIRQ output if enabled. A
read of this register will read the data from the
Keyboard Data or Command Write Buffer and
clear the IBF flag. Refer to the KIRQ and Status
register descriptions for more information.
Soft Powerdown Mode
This mode is entered by executing a HALT
instruction. The execution of program code is
halted until either RESET is driven active or a
data byte is written to the DBBIN register by a
master CPU. If this mode is exited using the
139
Host I/F Status Register
The Status register is 8 bits wide. Table 55 shows the contents of the Status register.
D7
D6
D5
Table 55 - Status Register
D4
D3
D2
D1
D0
UD
UD
UD
UD
IBF
OBF
C/D
UD
OBF
Output Buffer Full
This flag is set to 1 whenever the
FDC37C93xAPM CPU write to the output data
register (DBB). When the host system reads
the output data register, this bit is automatically
reset.
Status Register
This register is cleared on a reset. This register
is read-only for the Host and read/write by the
FDC37C93xAPM CPU.
UD
Writeable by FDC37C93xAPM CPU. These bits
are user-definable.
EXTERNAL CLOCK SIGNAL
The FDC37C93xAPM’s X1K clock source is a 12
MHz clock generated from a 14.318 MHz clock.
The reset pulse must last for at least 24 16
MHz clock periods.
The pulse-width
requirement applies to both internally - and
externally - generated reset signals.
In
powerdown mode, the external clock signal on
X1K is not loaded by the chip.
C/D
Command Data
This bit specifies whether the input data register
contains data or a command (0 = data, 1 =
command). During a host data/command write
operation, this bit is set to "1" if SA2 = 1 or reset
to "0" if SA2 = 0.
IBF
Input Buffer Full
This flag is set to 1 whenever the host system
writes data into the input data register. Setting
this flag activates the FDC37C93xAPM CPU's
nIBF (MIRQ) interrupt if enabled. When the
FDC37C93xAPM’s CPU reads the input data
register (DBB), this bit is automatically reset and
the interrupt is cleared. There is no output pin
associated with this internal signal.
The FDC37C93xAPM’s X1C clock source must
be from a crystal connected across X1C and
X2C. Due to the low current internal oscillator
circuit, this X1C can not be driven by an external
clock signal.
DEFAULT RESET CONDITIONS
The FDC37C93xAPM has one source of reset,
an external reset via the RESET pin. Refer to
Table 56 for the effect of each type of reset on
the internal registers.
140
DESCRIPTION
Table 56 - Resets
HARDWARE RESET (RESET)
KCLK
Weak High
KDAT
Weak High
MCLK
Weak High
MDAT
Weak High
Host I/F Data Reg
N/A
Host I/F Status Reg
00H
RTCCNTRL
80H
RTCADDR
NC
RTCDATA
NC
NC: No Change N/A: Not Applicable
GATEA20 AND KEYBOARD RESET
Port 92 Fast GateA20 and Keyboard Reset
The FDC37C93xAPM provides several options
for GateA20 and Keyboard Reset: 8042
Software Generated GateA20 and KRESET,
Fast GateA20 and KRESET (via Hardware
Speed-up) and Port 92 Fast GateA20 and
KRESET.
Port 92 Register
This port can only be read or written if Port 92
has been enabled via bit 2 of the KRST_GA20
Register (Logical Device 7, 0xF0) set to 1.
NAME
Location
Default Value
Attribute
Size
This register is used to support the alternate
reset (nALT_RST) and alternate A20 (ALT_A20)
functions.
PORT 92
92h
24h
Read/Write
8 bits
141
BIT
7:6
5
4
3
2
1
0
Table 57 - Port 92 Register
FUNCTION
Reserved. Returns 00 when read.
Reserved. Returns a 1 when read.
Reserved. Returns a 0 when read.
Reserved. Returns a 0 when read.
Reserved. Returns a 1 when read.
ALT_A20 Signal control. Writing a 0 to this bit causes the ALT_A20 signal to
be driven low. Writing a 1 to this bit causes the ALT_A20 signal to be driven
high.
Alternate System Reset. This read/write bit provides an alternate system reset
function. This function provides an alternate means to reset the system CPU to
effect a mode switch from Protected Virtual Address Mode to the Real Address
Mode. This provides a faster means of reset than is provided by the Keyboard
controller. This bit is set to a 0 by a system reset. Writing a 1 to this bit will
cause the nALT_RST signal to pulse acitive (low) for a minimum of 1 µs after a
delay of 500 ns. Before another nALT_RST pulse can be generated, this bit
must be written back to a 0.
Table 58 - nGATEA20
8042
P21
0
0
1
1
ALT_A20
0
1
0
1
Bit 0 of Port 92, which generates the nALT_RST
signal, is used to reset the CPU under program
control.
This signal is AND’ed together
externally with the reset signal (nKBDRST) from
the keyboard controller to provide a software
means of resetting the CPU. This provides a
faster means of reset than is provided by the
keyboard controller. Writing a 1 to bit 0 in the
Port 92 Register causes this signal to pulse low
for a minimum of 6µs after a delay of a
minimum of 14µs. Before another nALT_RST
pulse can be generated, bit 0 must be set to 0
either by a system reset of a write to Port 92.
Upon reset, this signal is driven inactive high (bit
0 in the Port 92 Register is set to 0).
System
nA20M
0
1
1
1
The diagram on the following page illustrates
the generation of the nALT_RST function. If
software control is selected, i.e., bit 0 of
KRST_GA20 is set to 0, the reset pulse is
generated by the 8042 upon writing an FE
command to register 64. If hardware speed-up
is selected, i.e., bit 0 of KRST_GA20 is set to 1,
the reset pulse is generated in hardware upon
writing an FE command to register 64.
In addition, if Port 92 is enabled, i.e., bit 2 of
KRST_GA20 is set to 1, then a pulse is also
generated by writing a 1 to bit 0 of the Port 92
Register and this pulse is ANDed with the
142
pulse generated above. This pulse is output on
pin KRESET and its polarity is controlled by the
GPI/O polarity configuration.
14us
~
~
6us
8042
P20
KRST
FE
Command
MUX
GPI/O Polarity
Config
Pulse
Gen
KRST_GA20
Bit 0
KRST_GA20
Bit 2
P92
KRESET
nALT_RST
Bit 0
Pulse
Gen
14us
~
~
Note: When Port 92 is disabled,
writes are ignored and reads
return undefined values.
6us
FIGURE 7 - KRESET GENERATION
Bit 1 of Port 92, the ALT_A20 signal, is used to
force nA20M to the CPU low for support of real
mode compatible software.
This signal is
externally OR’ed with the A20GATE signal from
the keyboard controller and CPURST to control
the nA20M input of the CPU. Writing a 0 to bit 1
of the Port 92 Register forces ALT_A20 low.
ALT_A20 low drives nA20M to the CPU low, if
A20GATE from the keyboard controller is also
low. Writing a 1 to bit 1 of the Port 92 Register
forces ALT_A20 high. ALT_A20 high drives
nA20M to the CPU high, regardless of the state
of A20GATE from the keyboard controller. Upon
reset, this signal is driven low.
The diagram on the following page illustrates
the logic for the generation of the Gate A20
signal.
143
GateA20 Logic
64&nAEN
KRST_GA20
Bit 1
A
nIOW
nIOW
DD1
nIOW
DFF
Address
8042
DFE
A
KRST_GA20
Bit 0
CPURST
To KRESET Gen
nAEN&60
A20GATE
nIOW
DD1
After D1
MUX
GPI/O Polarity
Config
GateA20
D[1]
GA20
nIOW
KRST_GA20
Bit 1
nAEN&64
nIOW
nAEN&60
D
KRST_GA20
Bit 2
Trailing Edge Delay
P92
ALT_A20
Bit 1
VCC
A
nIOW
24MHz
Delay
Note: When Port 92 is disabled,
writes are ignored and reads
return undefined values.
Note: Use 64 and 60 or the alternate addresses
for command and data ports.
FIGURE 8 - GATEA20 GENERATION LOGIC
The timing for a D1 command write followed by
a data write is shown on the following
page. This is the GATEA20 turn-on sequence
shown in the Table “GATE20 Command/Data
Sequence Examples”.
144
0ns
250ns
500ns
CLK
AEN
nAEN
64=I/O Addr
n64
nIOW
nA
DD1
nDD1
nCNTL
nIOW'
nIOW+n64
AfterD1
nAfterD1
60=I/O Addr
n60
nIOW+n60=B
nAfterD1+B
D[1]
GA20
FIGURE 9 - GATE A20 TURN-ON SEQUENCE TIMING
When writing to the command and data port
with hardware speedup, the IOW timing shown
in the figure titled “IOW Timing for Port 92” in
the Timing Diagrams Section is used. This
setup time is only required to be met when using
hardware speedup; the data must be valid a
minimum of 0 nsec from the leading edge of
the write and held throughout the entire write
cycle.
145
hardware speed-up feature. GATEA20 from the
chip is part of the control required to mask
address line A20 to emulate 8086 addressing.
FAST GATEA20 AND KEYBOARD RESET
GATEA20/KRESET Hardware Speed-Up
GATEA20 and KRESET is configured via a byte
at F0 in the keyboard configuration space,
Logical Device 7. The byte is defined below.
The FDC37C93xAPM contains on-chip logic
support for the GATEA20 and KRESET
NAME
KRST_GA20
Table 59 - GATEA20/KRESET
REG INDEX
DESCRIPTION
0xF0
Bits[7:3] Reserved
Bit[2] Port 92 Select
= 0 Port 92 Disabled
= 1 Port 92 Enabled
Bit[1] GATEA20 Select
= 0 8042 Software Control
= 1 Hardware Speed-up
Bit[0] KRESET Select
= 0 8042 Software Control
= 1 Hardware Speed-up
When the chip receives a "D1" command
followed by data (via the host interface), the onchip hardware copies the value of data bit 1 in
the received data field to the GATEA20 host
latch. It also copies the value of D[0] to
KRESET latch. At no time during this hostinterface transaction will PCOBF or the IBF flag
(bit 1) in the Status register be activated; i.e.,
this host control of GATEA20 is transparent to
firmware, with no consequent degradation of
overall system performance. Table 60 details
the possible GATEA20 sequences and the chip
responses.
STATE
C
On VCC1 POR, GATEA20 and KRESET pins
will float.
GATEA20 comes from either the software
control or hardware speed-up and they are
mutually exclusive.
If Port 92 is enabled,
GATEA20 from one of these two are merged
along with Port 92. See Port 92 Section.
KRESET comes from either the software control
or hardware speed-up and they are mutually
exclusive. If Port 92 is enabled, KRESET from
one of these two are merged along with Port 92.
See Port 92 Section.
146
SA2
1
0
1
1
0
1
1
1
0
1
1
1
0
1
1
1
1
R/W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Table 60 - GATEA20 Command/Data Sequence Examples
IBF
D[0:7]
FLAG
GATEA20
COMMENTS
GATEA20 Turn-on Sequence
Q
0
D1
1
0
D[1]=1
Q
0
FF
GATEA20 Turn-off Sequence
Q
0
D1
0
0
D[1]=0
Q
0
FF
GATEA20 Turn-on Sequence(*)
Q
0
D1
Q
0
D1
1
0
D[1]=1
Q
0
FF
GATEA20 Turn-off Sequence(*)
Q
0
D1
Q
0
D1
0
0
D[1]=0
Q
0
FF
Invalid Sequence
Q
0
D1
Q
1
XX**
Q
1
FF
Notes:
"Q" indicates the bit remains set at the previous state.
*Not a standard sequence.
**XX = Anything except D1.
If multiple data bytes, set IBF and wait at state 0. Let the software know something unusual
happened.
For data bytes SA2=0, only D[1] is used; all other bits are don't care.
The polarity control bit for GPI/O controls the polarity of GATEA20.
Table 61 below details the possible KRESET sequences and the chip responses.
SA2
1
Table 61 - KRESET Command/Data Sequence Examples
IBF
R/W
D[0:7]
FLAG
COMMENTS
W
FE
0
Pulse KRESET
When an FE command is received, pulse
KRESET.
KRESET is pulsed low for a
minimum of 6µs pulse width after a minimum of
a 14µs delay.
The polarity control bit for GPI/O controls the
polarity of KRESET.
147
REAL TIME CLOCK
RTC Reset
The Real Time Clock is a complete time of day
clock with two alarms, calendar (up to the year
9999), a programmable periodic interrupt, and a
programmable square wave generator.
The clock, calendar, or RAM functions are not
affected by the system reset (RESET_DRV
active). When the RESET_DRV pin is active
(i.e., system reset) and the battery voltage is
above 1 volt nominal, the following occurs:
Features
1.
•
•
•
•
•
•
•
Counts seconds, minutes, and hours of the
day.
Counts days of the week, date, month, year
and century.
Time of Day Alarm
Time Of Century Wake-Up Alarm
Binary or BCD representation of time,
calendar and alarms.
Three interrupts - each is separately
software maskable. (No daylight savings
time!)
256 Bytes of CMOS RAM.
2.
3.
4.
5.
6.
7.
8.
9.
Port Definition and Description
When RESET_DRV is active and the battery
voltage is below 1 volt nominal, the following
occurs:
OSC
Crystal Oscillator input.
frequency is 32.768 kHz.
Maximum
Periodic Interrupt Enable (PIE) is cleared to
0.
Alarm Interrupt Enable (AIE) bit is cleared
to 0.
Update Ended Interrupt Enable (UIE) bit is
cleared to 0.
Update Ended Interrupt Flag (UF) bit is
cleared to 0.
Interrupt Request Status Flag (IRQF) bit is
cleared to 0.
Periodic Interrupt Flag (PIF) is cleared to 0.
The RTC and CMOS registers are not
accessable.
Alarm Interrupt Flag (AF) is cleared to 0.
nIRQ pin is in high impedance state.
clock
1.
2.
148
Registers 00-0D are initialized to 00h.
Access to all registers from the host or
FDC37C93xAPM’s CPU (8042) are blocked.
RTC Interrupt
to a non-zero value. If IRQ 8 is selected then
the polarity of this IRQ 8 output is
programmable through a bit in the OSC Global
Configuration Register.
The interrupt generated by the RTC is an active
high output. The RTC interrupt output remains
high as long as the status bit causing the
interrupt is present and the corresponding
interrupt-enable
bit
is
set.
Activating
RESET_DRV or reading register C clears the
RTC interrupt.
INTERNAL REGISTERS
Table 62A shows the address map of the RTC,
ten bytes of time, calendar, and alarm 1 data,
four control and status bytes and 114 bytes of
"CMOS" registers.
The RTC Interrupt is brought out by
programming the RTC Primary Interrupt Select
ADDRESS
Table 62A - Real Time Clock Address Map, Bank 0
REGISTER TYPE
REGISTER FUNCTION
0
R/W
Register 0: Seconds
1
R/W
Register 1: Seconds Alarm 1
2
R/W
Register 2: Minutes
3
R/W
Register 3: Minutes Alarm 1
4
R/W
Register 4: Hours
5
R/W
Register 5: Hours Alarm 1
6
R/W
Register 6: Day of Week
7
R/W
Register 7: Date of Month
8
R/W
Register 8: Month
9
R/W
Register 9: Year
A
R/W
Register A:
B
R/W
Register B: (Bit 0 is Read Only)
C
R
Register C:
D
R
Register D:
E-7F
R/W
Register E-7F: General Purpose
All 14 bytes are directly writable and readable by
the host with the following exceptions:
a.
b.
c.
149
Registers C and D are read only
Bit 7 of Register A is read only
Bits 0 of Register B is read only
All 128 bytes are directly writeable and readable
by the host.
Table 62B shows Bank 1, the second bank of
CMOS registers which contains an additional
128 bytes of general purpose CMOS registers.
ADDRESS
0-7F
Table 62B - Real Time Clock Address Map, Bank 1
REGISTER TYPE
REGISTER FUNCTION
R/W
Register 0-7F: General Purpose
All 9 bytes are directly writable and readable by
the host.
Table 62C shows the address map of Bank 2,
the third bank of CMOS registers, which contain
the registers for the century byte and the second
alarm function.
ADDRESS
Table 62C - Real Time Clock Address Map, Bank 2
REGISTER TYPE
REGISTER FUNCTION
40
R/W
Register 0: Century Byte
41
R/W
Register 1: Seconds Alarm 2
42
R/W
Register 2: Minutes Alarm 2
43
R/W
Register 3: Hours Alarm 2
44
R/W
Register 4: Day of Week Alarm 2
45
R/W
Register 5: Date of Month Alarm 2
46
R/W
Register 6: Month Alarm 2
47
R/W
Register 7: Year Alarm 2
48
R/W
Register 8: Control Register 1
Note: One or two of the three banks of CMOS
Registers are selected via the RTC Mode
Register (Logical Device 6, 0xF0). Banks 1 and
2 are also relocatable via the RTC Mode
Register and the Secondary Base Address
(CR62 and CR63). See Configuration Section.
and seven alarm 2 bytes can also be in binary
or BCD as shown in Table 63B.
Before initializing the internal registers, the SET
bit in Register B should be set to a "1" to prevent
time/calendar updates from occurring. The
program initializes the ten locations in the binary
or BCD format as defined by the DM bit in
Register B. The SET bit may now be cleared to
allow updates.
Time Calendar and Alarm
The processor program obtains time and
calendar information by reading the appropriate
locations. The program may initialize the time,
calendar and alarm by writing to these locations.
The contents of the ten time, calendar and
alarm 1 bytes can be in binary or BCD as shown
in Table 63A. The contents of the century byte
The 12/24 bit in Register B establishes whether
the hour locations represent 1 to 12 or 0 to 23.
The 12/24 bit cannot be changed without
reinitializing the hour locations. When the 12
150
The three alarm 1 bytes may be used in two
ways. First, when the program inserts an alarm
time in the appropriate hours, minutes and
seconds alarm locations, the alarm interrupt is
initiated at the specified time each day if the
alarm enable bit is high. The second usage is to
insert a "don't care" state in one or more of three
alarm bytes. The "don't care" code is any
hexadecimal byte from C0 to FF inclusive. That
is the two most significant bits of each byte,
when set to "1" create a "don't care" situation.
An alarm interrupt each hour is created with a
"don't care" code in the hours alarm location.
Similarly, an alarm is generated every minute
with "don't care" codes in the hours and minutes
alarm bytes. The "don't care" codes in all three
alarm bytes create an interrupt every second.
hour format is selected, the high order bit of the
hours byte represents PM when it is a "1".
Once per second, the ten time, calendar and
alarm 1 bytes as well as the century byte and
seven alarm 2 bytes are switched to the update
logic to be advanced by one second and to
check for an alarm condition. If any of these
bytes are read at this time, the data outputs are
undefined. The update cycle time is shown in
Table 63. The update logic contains circuitry for
automatic end-of-month recognition as well as
automatic leap year compensation.
151
Table 63A - Time, Calendar and Alarm 1 Bytes
REGISTER FUNCTION
BCD RANGE
ADD
BINARY RANGE
0
Register 0: Seconds
00-59
00-3B
1
Register 1: Seconds Alarm
00-59
00-3B
2
Register 2: Minutes
00-59
00-3B
3
Register 3: Minutes Alarm
00-59
00-3B
4
Register 4: Hours
5
01-12 am
01-0C
(12 hour mode)
81-92 pm
81-8C
(24 hour mode)
00-23
00-17
01-12 am
01-0C
(12 hour mode)
81-92 pm
81-8C
(24 hour mode)
00-23
00-17
01-07
Register 5: Hours Alarm
6
Register 6: Day of Week
01-07
7
Register 7: Day of Month
01-31
01-1F
8
Register 8: Month
01-12
01-0C
9
Register 9: Year
00-99
00-63
ADDRESS
40h
41h
42h
43h
44h
45h
46h
47h
Table 63B - Century Byte and Alarm 2 Bytes
DECIMAL
REGISTER FUNCTION
RANGE
BCD RANGE
Register 0: Century Byte
0-99
00-99
Register 1: Seconds Alarm 2
0-59
00-59
Register 2: Minutes Alarm 2
0-59
00-59
12-hr
1-12
01-12 AM
Register 3: Hours Alarm 2
mode
81-92 PM
24-hr
0-23
00-23
mode
Register 4: Day of Week Alarm 2
1-7
01-07
Register 5: Date of Month Alarm 2
1-31
01-31
Register 6: Month Alarm 2
1-12
01-12
Register 7: Year Alarm 2
0-99
00-99
BINARY RANGE
00-63
00-3B
00-3B
01-0C AM
81-8C PM
00-17
01-07
01-1F
01-0C
00-63
Alarm 2 Function
Alarm 2 can only be used as a wake-up alarm to
turn on power to the system when the system is
powered off. There are two bits used to control
alarm 2. The alarm 2 wake-up function is
enabled via the alarm 2 Enable bit, AL2_EN, in
the Soft Power Enable Register 2. The alarm 2
Remember Enable bit, AL2_REM_EN, in the
RTC Control Register 1, is used to power-up the
152
code is set in the year, month, date, day and
hours alarm byte. An alarm is generated every
minute with “don’t care” codes in the year,
month, date, day, hours and minutes alarm
bytes. The “don’t care” codes in all seven alarm
bytes creates an interrupt every second. As a
final example, an alarm is generated every one
of a certain day of the week, i.e., every Friday,
by specifying the “don’t care” code in the year,
month and date of month bytes.
system upon return of power if the alarm 2 time
has passed during loss of power. These bits
function as follows:
If VTR is present: AL2_EN controls whether or
not alarm 2 is enabled as a wake-up function. If
AL2_EN is set and VTR=5V, the nPowerOn pin
will go active (low) when the date/time is equal
to the alarm 2 date/time and the power supply
will turn on the machine.
If VTR is not present: AL2_REM_EN controls
whether or not Alarm 2 will power-up the system
upon the return of VTR, regardless of the value
of AL2_EN. If AL2_REM_EN is set and VTR=0
at the date/time that Alarm 2 is set for, the
nPowerOn pin will go active (low) as soon as
VTR comes back and the machine will powerup.
Update Cycle
An update cycle is executed once per second if
the SET bit in Register B is clear and the
DV0-DV2 divider is not clear. The SET bit in the
"1" state permits the program to initialize the
time and calendar bytes by stopping an existing
update and preventing a new one from
occurring.
The seven alarm 2 bytes may be used in two
ways. First, when the alarm time is written in
the appropriate year, month, date, day, hours,
minutes, and seconds alarm locations, the
alarm interrupt is initiated at the specified time
on the day of the week, on the date of the
month, in the year if the Alarm 2 Enable bit is
high. The second usage is to insert a “don’t
care” state into one or more of the alarm bytes.
The “don’t care” code is any hexadecimal byte
from C0 to FF inclusive. That is, the two most
significant bits of each byte, when set to “1”
create a “don’t care” situation. An alarm is
generated each year if the year byte is set to a
“don’t care” condition. Similarly, an alarm is
generated every month with “don’t care” codes
in the year and month bytes. An alarm is
generated on every day of every month of every
year with “don’t care” codes in the year, month,
date of month and day of week bytes. An alarm
is generated each hour, every day of the month,
every month, every year when the “don’t care”
The primary function of the update cycle is to
increment the seconds byte, check for overflow,
increment the minutes byte when appropriate
and so forth through to the year of the century
byte. The update cycle also compares each
alarm byte with the corresponding time byte and
issues an alarm if a match or if a "don't care"
code is present.
The length of an update cycle is shown in Table
58. During the update cycle the time, calendar
and alarm bytes are not accessible by the
processor program. If the processor reads these
locations before the update cycle is complete
the output will be undefined. The UIP (update in
progress) status bit is set during the interval.
When the UIP bit goes high, the update cycle
will begin 244 us later. Therefore, if a low is read
on the UIP bit the user has at least 244µs before
time/calendar data will be changed.
153
Table 64 - Update Cycle Time
INPUT CLOCK
FREQUENCY
UIP BIT
UPDATE CYCLE TIME
MINIMUM TIME
UPDATE CYCLE
32.768 kHz
32.768 kHz
1
0
1948 µs
-
244 µs
CONTROL AND STATUS REGISTERS, BANK
0
times when Bank 0 is enabled, even during the
update cycle.
Bank 0 of the RTC has four registers which are
accessible to the processor program at all
REGISTER A (AH)
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
UIP
DV2
DV1
DV0
RS3
RS2
RS1
RS0
UIP
The update in progress bit is a status flag that
may be monitored by the program. When UIP is
a "1" the update cycle is in progress or will soon
begin. When UIP is a "0" the update cycle is not
in progress and will not be for at least 244us.
The time, calendar, and alarm information is
fully available to the program when the UIP bit is
zero. The UIP bit is a read only bit and is not
affected by RESET_DRV. Writing the SET bit in
Register B to a "1" inhibits any update cycle and
then clears the UIP status bit. The UIP bit is
only valid when the RTC is enabled. Refer to
Table 64.
also used to reset the divider chain. When the
time/calendar is first initialized, the program
may start the divider chain at the precise time
stored in the registers. When the divider reset is
removed the first update begins one-half second
later. These three read/write bits are not affected
by RESET_DRV.
RS3-0
The four rate selection bits select one of 15 taps
on the divider chain or disable the divider
output. The selected tap determines rate or
frequency of the periodic interrupt. The program
may enable or disable the interrupt with the PIE
bit in Register B. Table 66 lists the periodic
interrupt rates and equivalent output frequencies
that may be chosen with the RS0-RS3 bits.
These four bits are read/write bits which are not
affected by RESET_DRV.
DV2-0
Three bits are used to permit the program to
select various conditions of the 22 stage divider
chain. Table 65 shows the allowable
combinations. The divider selection bits are
154
Table 65 - Divider Selection Bits
REGISTER A BITS
OSCILLATOR
FREQUENCY
32.768 KHz
32.768 KHz
32.768 KHz
32.768 KHz
32.768 KHz
DV2
0
0
0
0
1
1
DV1
0
0
1
1
0
1
DV0
0
1
0
1
X
X
MODE
Oscillator Disabled
Oscillator Disabled
Normal Operate
Test
Test
Reset Driver
Table 66 - Periodic Interrupt Rates
RATE SELECT
32.768 kHz TIME BASE
RS3
RS2
RS1
RS0
PERIOD RATE OF
INTERRUPT
0
0
0
0
0.0
0
0
0
1
3.90625 ms
256 Hz
0
0
1
0
7.8125 ms
128 Hz
0
0
1
1
122.070 us
8.192 kHz
0
1
0
0
244.141 us
4.096 kHz
0
1
0
1
488.281 us
2.048 kHz
0
1
1
0
976.562 us
1.024 kHz
0
1
1
1
1.953125 ms
512 Hz
1
0
0
0
3.90625 ms
256 Hz
1
0
0
1
7.8125 ms
128 Hz
1
0
1
0
15.625 ms
64 Hz
1
0
1
1
31.25 ms
32 Hz
1
1
0
0
62.5 ms
16 Hz
1
1
0
1
125 ms
8 Hz
1
1
1
0
250 ms
4 Hz
1
1
1
1
500 ms
2 Hz
155
FREQUENCY OF
INTERRUPT
REGISTER B (BH)
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
SET
PIE
AIE
UIE
RES
DM2
24/12
DSE
"0". The AIE bit is not affected by any internal
functions.
SET
When the SET bit is a "0", the update functions
normally by advancing the counts once per
second. When the SET bit is a "1", an update
cycle in progress is aborted and the program
may initialize the time and calendar bytes
without an update occurring in the middle of
initialization. SET is a read/write bit which is
not modified by RESET_DRV or any internal
functions.
UIE
The update-ended interrupt enable bit is a
read/write bit which enables the update-end flag
(UF) bit in Register C to assert IRQB. The
RESET_DRV port or the SET bit going high
clears the UIE bit.
RES
Reserved - read as “0”.
PIE
The periodic interrupt enable bit is a read/write
bit which allows the periodic-interrupt flag (PF)
bit in Register C to cause the IRQB port to be
driven low. The program writes a "1" to the PIE
bit in order to receive periodic interrupts at the
rate specified by the RS3-RS0 bits in Register
A. A zero in PIE blocks IRQB from being
initiated by a periodic interrupt, but the periodic
flag (PF) is still set at the periodic rate. PIE is
not modified by any internal function, but is
cleared to "0" by a RESET_DRV.
DM
The data mode bit indicates whether time and
calendar updates are to use binary or BCD
formats. The DM bit is written by the processor
program and may be read by the program,
but is not modified by any internal functions
or by RESET_DRV. A "1" in DM signifies
binary data, while a "0" in DM specifies BCD
data.
24/12
The 24/12 control bit establishes the format of
the hours byte as either the 24 hour mode if
set to a "1", or the 12 hour mode if cleared to
a "0". This is a read/write bit which is not
affected by RESET_DRV or any internal
function.
AIE
The alarm interrupt enable bit is a read/write bit,
which when set to a "1" permits the alarm flag
(AF) bit in Register C to assert IRQB. An
alarm interrupt occurs for each second that the
three time bytes equal the three alarm bytes
(including a "don't care" alarm code of binary
11XXXXXX). When the AIE bit is a "0", the AF
bit does not initiate an IRQB signal. The
RESET_DRV
port
clears
AIE
to
DSE
The daylight savings enable bit is read only and
is always set to a "0" to indicate that the daylight
savings time option is not available.
156
REGISTER C (CH) - READ ONLY REGISTER
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
IRQF
PF
AF
UF
0
0
0
0
AF
The alarm interrupt flag when set to a "1"
indicates that the current time has matched the
alarm time. A "1" in AF causes a "1" to appear in
IRQF and the IRQB port to go low when the AIE
bit is also a "1". A RESET_DRV or a read of
Register C clears the AF bit.
IRQF
The interrupt request flag is set to a "1" when
one or more of the following are true:
PF = PIE = 1
AF = AIE = 1
UF = UIE = 1
Any time the IRQF bit is a "1", the IRQB signal
is driven low. All flag bits are cleared after
Register C is read or by the RESET_DRV port.
UF
The update-ended interrupt flag bit is set after
each update cycle. When the UIE bit is also a
"1", the "1" in UF causes the IRQF bit to be set
and asserts IRQB. A RESET_DRV or a read of
Register C causes UF to be cleared.
PF
The periodic interrupt flag is a read-only bit
which is set to a "1" when a particular edge is
detected on the selected tap of the divider chain.
The RS3 -RS0 bits establish the periodic rate.
PF is set to a "1" independent of the state of
the PIE bit. PF being a "1" sets the IRQF bit
and initiates an IRQB signal when PIE is also a
"1". The PF bit is cleared by RESET_DRV or by
a read of Register C.
b3-0
The unused bits of Register C are read as zeros
and cannot be written.
157
REGISTER D (DH) READ ONLY REGISTER
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
VRT
0
0
0
0
0
0
0
The processor program selects which interrupts,
if any, it wishes to receive by writing a "1" to the
appropriate enable bits in Register B. A "0" in
an enable bit prohibits the IRQB port from being
asserted due to that interrupt cause. When an
interrupt event occurs a flag bit is set to a "1" in
Register C. Each of the three interrupt sources
have separate flag bits in Register C, which are
set independent of the state of the
corresponding enable bits in Register B. The
flag bits may be used with or without enabling
the corresponding enable bits. The flag bits in
Register C are cleared (record of the interrupt
event is erased) when Register C is read.
Double latching is included in Register C to
ensure the bits that are set are stable
throughout the read cycle. All bits which are
high when read by the program are cleared, and
new interrupts are held until after the read cycle.
If an interrupt flag is already set when the
interrupt becomes enabled, the IRQB port is
immediately activated, though the interrupt
initiating the event may have occurred much
earlier.
VRT
When a "1", this bit indicates that the contents
of the RTC are valid. A "0" appears in the VRT
bit when the battery voltage is low. The VRT bit
is read only bit which can only be set by a read
of Register D. Refer to Power Management for
the conditions when this bit is reset. The
processor program can set the VRT bit when the
time and calendar are initialized to indicate that
the time is valid.
b6:b0
The remaining bits of Register D are read as
zeros and cannot be written.
Register EH-FFH: General purpose
Registers Eh-FFH are general purpose CMOS
registers. These registers can be used by the
host or 8042 and are fully available during the
time update cycle.
The contents of these
registers are preserved by the battery power.
INTERRUPTS
When an interrupt flag bit is set and the
corresponding interrupt-enable bit is also set,
the IRQB port is driven low. IRQB is asserted as
long as at least one of the three interrupt
sources has its flag and enable bits both set.
The IRQF bit in Register C is a "1" whenever the
IRQB port is being driven low.
The RTC includes three separate fullyautomatic sources of interrupts to the processor.
The alarm interrupt may be programmed to
occur at rates from one-per-second to
one-a-day.
The periodic interrupt may be
selected for rates from half-a-second to 122.070
µs. The update ended interrupt may be used
to indicate to the program that an update cycle
is completed.
Each of these independent
interrupts are described in greater detail in
other sections.
158
Control Registers, Bank 2
CONTROL REGISTER 1
Bank 2 of the RTC has one control register.
Default is 0; cleared upon Vbat POR. This
register is battery backed-up.
D7
0
D6
0
D5
0
D4
0
D3
0
D2
VTR_POR
_EN
D1
0
D0
AL2_REM
_EN
Frequency Divider
AL2_REM_EN - One of the two control bits for
the Alarm 2 wakeup function; it is the
“remember” enable bit for the second alarm.
This bit, if set to 1, wil cause the system to
power-up upon return of power if the Alarm 2
time has passed during loss of power. It is only
applicable when VTR=0. This bit is independent
of the other control bit for the Alarm 2 wake-up
function, Al2_EN (bit 4 of the Soft Power Enable
Register 2) which controls Alarm 2 when
VTR=5V. See the Alarm 2 Function Section for
more information. The function of Bit 0 is
summarized as follows:
The RTC has 22 binary divider stages following
the clock input. The output of the divider is a 1
Hz signal to the update-cycle logic. The divider
is controlled by the three divider bits (DV3-DV0)
in Register A. As shown in Table 65 the divider
control bits can select the operating mode or
be used to hold the divider chain reset which
allows precision setting of the time. When the
divider chain is changed from reset to the
operating mode, the first update cycle is
one-half second later. The divider control bits
are also used to facilitate testing of the RTC.
If AL2_REM_EN is set and VTR=0 at the
date/time that Alarm 2 is set for, the nPowerOn
pin will go active (low) and the machine will
power-up as soon as VTR comes back.
Periodic Interrupt Selection
The periodic interrupt allows the IRQB port to be
triggered from once every 500 ms to once every
122.07 µs. As Table 66 shows, the periodic
interrupt is selected with the RS0-RS3 bits in
Register A. The periodic interrupt is enabled
with the PIE bit in Register B.
VTR POR - The enable bit for VTR POR. If
VTR_POR_EN is set, the nPowerOn pin will go
active (low) and the machine will power-up as
soon as a VTR POR occurs.
159
Power Supply Operational Modes
1.
Note: See the Operational Description Section
for the Power Supply Operational Modes.
2.
3.
Power Management
The RAMD signal controls all bus inputs to the
RTC and RAM (nIOW, nIOR, RESET_DRV).
When asserted, it disallows any modification of
the RTC and RAM data by the host or 8042.
RAMD is asserted whenever: VCC is below 4.0
volts nominal.
The Divider Chain Controls (bits 6-4) are in
any mode but Normal Operation ("010").
The VRT bit is a "0".
When battery voltage is below 1 volt
nominal and RESET_DRV is a "1". This
will also initialize all registers 00-0D to a
"00".
To minimize power consumption, the oscillator
is not operational under the following conditions:
1.
2.
When the VTR voltage drops below the battery
voltage, the RTC switches to battery power.
When VTR rises above the battery voltage, the
RTC switches back to VTR power.
When the VCC voltage drops below 4.0 volts
nominal, all inputs are locked out so that the
internal registers cannot be modified by the
system. This lockout condition continues for 62
msec (min) to 125 msec (max) after the system
power has been restored. The 62 msec lockout
does not occur under the following conditions:
The Divider Chain Controls (bits 6-4) are in
Oscillator Disabled mode (000, or 001).
If VTR and VCC=0 and the battery power is
removed and then re-applied (a new battery
is installed) the following occurs:
a. The oscillator is disabled immediately.
b. Initialize all registers 00-0D to a "00"
when VCC is applied.
If the battery voltage is between 1 volt nominal
and 2.4 volt nominal when VCC is applied:
1.
Clear VRT bit to "0". Maintain all other RTC
bits in the state as before VCC was applied
VCC
HYSTER
BATTERY
REGISTER ACCESS
<4.0
1
1
N
>4.0
0
x
Y
Hyster=1 implies that VCC <4.0 volts +/-0.25V; Hyster=0 implies that VCC >4.0
volts +/-0.25V.
160
SOFT POWER MANAGEMENT
transition on the Button input or on any of the
enabled wakeup events (SPx) causes the
nPowerOn output to go active low which turns
on the main power supply. Even if the power
supply is completely lost (i.e., VTR is not
present) the power supply can still be turned on
upon the return of VTR by an alarm 2 event that
has already passed (if the alarm 2 remember bit
is enabled) or by a VTR power on reset (if the
VTR POR bit is enabled). These bits are
described in the RTC section.
The FDC37C93xAPM employs soft power
management to allow the chip to enter low
power mode and to provide a variety of wakeup
events to power up the chip. This technique
allows for software control over powerdown and
wakeup events. In low power mode, the chip
runs off of the trickle voltage, VTR, which is 5
volts at 2mA maximum. In this mode, the chip
is ready to power up from either the power
button or from one of a number of wakeup
events including pressing a key, touching the
mouse or receiving data from one of the UARTs.
The alarm can also be set to power up the
system at a predetermined time to perform one
or more tasks.
The Button input can be used to turn off the
power supply after a debounce delay. The
power supply can also be turned off under
software control (via a write to register
WDT_CTRL with bit 7 set).
The implementation of Soft Power Management
is illustrated in Figure 11. A high to low
161
Soft Power Mangement
OFF_EN
Button
nBINT
Delay2
Logic
OFF_DLY
nSPOFF1
nSPOFF
L
VTR_POR_EN
VTR POR
AL2_REM_EN
Button Input
Logic
Alarm 2
ED; PG
SP1
OFF_DLY
Delay1
VTR
ED; L
EN1
Flip
Flop 1
D
nSPOFF1
nPowerOn
Q
CLR
Open Collector
Type output
SPx
ED; L
VBAT POR
ENx
Logic
nSPOFF1
Soft Power
Off nSPOFF1
Override
Timer
PWRBTNOR_EN
PWRBTNOR_STS
A transition on the Button input or on any enabled SPx inputs causes the nPowerOn output to go active low.
A low pulse on the Soft Power Off signal causes the nPowerOn bit to float.
ED;PG = Edge Detect, Pulse Generator
ED;L = Edge Detect and Latch
FIGURE 11 - SOFT POWER MANAGEMENT FUNCTIONAL DIAGRAM
Note 1: All soft power management functions run off of VTR. When VTR is present, it supplies power
to the RTC. When VTR is not present, Vbat supplies power to the RTC and Flip Flop 1.
Note 2: Flip Flop 1 is battery backed-up so that it returns the last valid state of the machine.
Note 3: A battery backed-up enable bit in the alarm control register can be set to force Flip Flop 1 in
the soft power management circuit to come up ‘on’ if an alarm occurred when VTR was not present.
This is gated into wakeup circuitry. Refer to the AL2_REM_EN Bit description in the RTC Control
Register section for more information.
162
This register contains the status for the wake-up
events. Note: The status bit gets set if the
wakeup event occurs, whether or not it is
enabled as a wakeup function by setting the
corresponding bit in Soft Power Enable Register
1. However, only the enabled wakeup functions
will turn on power to the system.
REGISTERS
The following registers can be accessed when in
configuration mode at Logical Device 8,
Registers B0-B3, B8 and F4, and when not in
configuration they can be accessed through the
Index and Data Register.
Soft Power Status Register 2
(Configuration Register B3, Logical Device 8)
This register contains additional status for the
wake-up events. Note: The status bit gets set if
the wakeup event occurs, whether or not it is
enabled as a wakeup function by setting the
corresponding bit in Soft Power Enable Register
2. However, only the enabled wakeup functions
will turn on power to the system.
Soft Power Enable Registers
Soft Power Enable Register 1
(Configuration Register B0, Logical Device 8)
This register contains the enable bits for the
wake-up function of the nPowerOn bit. When
enabled, these bits allow their corresponding
function to turn on power to the system.
Soft Power Enable Register 2
(Configuration Register B1, Logical Device 8)
This register contains additional enable bits for
the wake-up function of the nPowerOn bit.
When enabled, these bits allow their
corresponding function to turn on power to the
system. It also contains OFF_EN: After power
up, this bit defaults to 1, i.e., enabled. This bit
allows the software to enable or disable the
button control of power off.
Soft Power Control Registers
WDT_CTRL
(Configuration Register F4, Logical Device 8)
This register is used for soft power management
and watchdog timer control. Bits[7:5] are for soft
power management: SPOFF, Restart_Cnt,
Stop_Cnt.
Delay 2 Time Set Register
(Configuration Register B8, Logical Device 8)
This register is used to set Delay 2 to value from
500msec to 32sec. The default value is
500msec.
Soft Power Status Registers
Soft Power Status Register 1
(Configuration Register B2, Logical Device 8)
163
to turn off the system. The override status bit
alerts the system upon power-up that an
override event was used to power down the
system, and will be used to properly power-up
the system.
The power button has an override event as
required by the ACPI specification. If the user
presses the power button for more than four
seconds while the system is in the working
state, a hardware event is generated and the
system will transition to the off state. There are
status and enable bits associated with this
feature in the PM1_BLK registers. See the ACPI
section.
Figure 11 shows the soft power management
logic with the override timer path from the
button input. The override timer counts while
the button is held (in the present implementation
this would be when the button input is high) and
is cleared upon release of the button. It has a
0.5 second or faster resolution (run off of the
32kHz clock divided down) and the minimum
time for triggering the override power down is
four seconds, with a maximum of 4.5 seconds.
The timer output will pulse the clear on the Flip
Flop 1.
This override event utilizes power button logic to
determine that the power button (Button_In) has
been pressed for more that four seconds. The
override enable/disable bit, PWRBTNOR_EN,
allows this override function to be turned on/off.
If enabled, this override event will result in
setting
the
override
status
bit,
PWRBTNOR_STS (to be cleared by writing a 1
to its bit position - writing a 0 has no effect),
clearing the regular button status bit,
PWRBTN_STS, and generating an event to be
routed into the soft power management logic
Figure 12 illustrates the timing of the blanking
period relative to Button_In and nPowerOn for
the override event.
Button_In
4+
sec
Release
nPowerOn
4 sec
Blanking Period
4 sec
Vcc
FIGURE 12 - BLANKING PERIOD
164
SYSTEM MANAGEMENT INTERRUPT (SMI)
The FDC37C93xAPM implements a group nSMI
output pin. The System Management Interrupt
is a non-maskable interrupt with the highest
priority level used for transparent power
management. The nSMI group interrupt output
consists of the enabled interrupts from each of
the functional blocks in the chip. The interrupts
are enabled onto the group nSMI output via the
SMI Enable Registers 1 and 2. The nSMI output
is then enabled onto the group nSMI output pin
via bit[7] in the SMI Enable Register 2. The
logic equation for the nSMI output is as follows:
nSMI =
(EN_IDE1
and
IRQ_IDE1)
(EN_PINT
and
IRQ_PINT)
(EN_U2INT and IRQ_U2INT)
(EN_U1INT and IRQ_U1INT)
(EN_FINT
and
IRQ_FINT)
(EN_GPINT2 and IRQ_GPINT2)
(EN_GPINT1 and IRQ_GPINT1)
(EN_WDT
and
IRQ_WDT)
(EN_MINT
and
IRQ_MINT)
(EN_KINT
and
IRQ_KINT)
(EN_IRINT
and
IRQ_IRINT)
(EN_BINT
and
iRQ_BINT)
(EN_ABINT and IRQ_ABINT)
SMI Enable Registers
SMI Enable Register 1
(Configuration Register B4, Logical Device 8)
This register is used to enable the different
interrupt sources onto the group nSMI output.
SMI Enable Register 2
(Configuration Register B5, Logical Device 8)
This register is used to enable additional
interrupt sources onto the group nSMI output.
This register is also used to enable the group
nSMI output onto the nSMI GPI/O pin and the
routing of 8042 P12 internally to nSMI.
or
or
or
or
or
or
or
or
or
or
or
or
SMI Status Registers
SMI Status Register 1
(Configuration Register B6, Logical Device 8)
This register is used to read the status of the
SMI input events. Note: The status bit gets set
whether or not the interrupt is enabled onto the
group SMI output.
SMI Status Register 2
(Configuration Register B7, Logical Device 8)
This register is used to read the status of the
SMI input events. Note: The status bit gets set
whether or not the interrupt is enabled onto the
group SMI output.
REGISTERS
The following registers can be accessed when in
configuration mode at Logical Device 8,
Registers B4-B7 and when not in configuration
they can be accessed through the Index and
Data Register.
165
ACCESS.bus
device driver interface, and several specific
device protocols.
The FDC37C93xAPM supports ACCESS.bus.
ACCESS.bus is a serial communication protocol
between a computer host and its peripheral
devices. It provides a simple, uniform and
inexpensive way to connect peripheral devices
to a single computer port. A single ACCESS.bus
on a host can accommodate up to 125
peripheral devices.
For a description of the ACCESS.bus protocol,
please refer to the ACCESS.bus Specifications
Version 2.2, February 1994, available from the
ACCESS.bus Industry Group.
The ACCESS.bus interface is based on the
PDC8584 controller. The registers are mapped
into the ISA I/O register space as set by the
configuration registers. The addresses for the
registers are shown in Table 67.
The ACCESS.bus protocol includes a physical
layer based on the I2C serial bus developed by
Philips, and several software layers.
The
software layers include the base protocol, the
Table 67 - ACCESS.bus Register Addresses
ADDRESS*
REGISTER
Base+0
Control/Status
Base+1
Own Address
Base+2
Data
Base+3
Clock
Note 1: Base I/O Range: [0x00:0x0FFC] on 4 byte boundaries
ACCESS.bus.
Register
S1
contains
ACCESS.bus status information required for bus
access and or monitoring.
REGISTERS
The ACCESS.bus interface has four internal
register locations. Two of these, Own Address
Register S0 and Clock Register S2, are used for
initialization of the chip. Normally they are only
written once directly after resetting of the chip.
The other two registers, the Data Shift Register
S0 and the Control/Status Register S1 (which
functions as a double register), are used during
actual data transmission/reception. Register S0
performs all serial-to-parallel interfacing with the
ACCESS.bus Control/Status Register S1
The control/status register controls the
ACCESS.bus operation and provides status
information. This register has separate read and
write functions for all bit positions. The writeonly section provides register access control
and control over ACCESS.bus signals, while the
read-only section provides ACCESS.bus status
information.
166
Table 68 - ACCESS.BUS Control/Status Register S1:
Control
D7
D6
D5
D4
D3
D2
D1
D0
R/W
W
W
W
W
W
W
W
W
Bit Def
PIN
ES0
Reserved
Reserved
ENI
STA
STO
ACK
Status
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R
R
R
R
R
R
R
R
PIN
0
STS
BER
LRB
AAS
LAB
nBB
Bit Def
communication with serial shift register S0 is
enabled and the S1 bus status bits are made
available for reading. With ESO = 0, bits ENI,
STA, STO and ACK of S1 can be read for test
purposes.
Bit Definitions
Register S1 Control Section
The write-only section of S1 enables access to
registers S0, S0’, S1 and S2, and controls
ACCESS.bus operation.
BITS 5 and 4: Reserved
BIT 3: ENI
This bit enables the internal interrupt, nINT,
which is generated when the PIN bit is active
(logic “0”).
BIT 7: PIN
Pending Interrupt Not. When the PIN bit is
written with a logic 1, all status bits are reset to
logic 0, with the exception of PIN which is set to
1, and nBB which is not affected. This may
serve as a software reset function.
BITS 2 and 1: STA and STO
These bits control the generation of the
ACCESS.bus
START
condition
and
transmission of slave address and R/nW bit,
generation of repeated START condition, and
generation of the STOP condition (see Table 69)
BIT 6: ESO
Enable Serial Output. ESO enables or disables
the serial ACCESS.bus I/O. When ESO is high,
ACCESS.bus communication is enabled;
STA
1
STO
0
1
0
0
1
1
1
0
0
Table 69 - Instruction Table for Serial Bus Control
PRESENT MODE
FUNCTION
OPERATION
SLV/REC
START
Transmit START+address, remain
MST/TRM if R/nW=0; go to MST/REC if
R/nW=1
MST/TRM
REPEAT START Same as for SLV/REC
MST/REC;
STOP READ;
Transmit STOP go to SLV/REC mode;
MST/TRM
STOP WRITE
Note 1
MST
DATA CHAINING Send STOP, START and address after
last master frame without STOP sent;
Note 2
ANY
NOP
No operation; Note 3
167
also set to logic “1” (inactive) each time S0 is
written.
In receiver mode, the PIN bit is
automatically set to logic “1” each time the data
register S0 is read.
Note 1: In master receiver mode, the last byte
must be terminated with ACK bit high (‘negative
acknowledge’)
Note 2: If both STA and STO are set high
simultaneously in master mode, a STOP
condition followed by a START condition +
address will be generated.
This allows
‘chaining’ of transmissions without relinquishing
bus control.
After transmission or reception of one byte on
the ACCESS.bus (9 clock pulses, including
acknowledge) the PIN bit will be automatically
reset to logic “0” (active) indicating a complete
byte transmission/reception. When the PIN bit
is subsequently set to logic “1” (inactive), all
status bits will be reset to “0” on a BER (bus
error) condition.
Note 3: All other STA and STO mode
combinations not mentioned in Table 69 are
NOPs.
In polled applications, the PIN bit is tested to
determine when a serial transmission/reception
has been completed. When the ENI bit (bit 4 of
write-only section of register S1) is also set to
logic 1 the hardware interrupt is enabled. In this
case, the PI flag also triggers and internal
interrupt (active low) via the nINT output each
time PIN is reset to logic “0”.
BIT 0: ACK
This bit must be set normally to logic “1”. This
causes the ACCESS.bus to send an
acknowledge automatically after each byte (this
occurs during the ninth clock pulse) . The bit
must be reset (to logic 0) when the
ACCESS.bus controller is operating in
master/receiver mode and requires no further
data to be sent from the slave transmitter. This
causes a negative acknowledge on the
ACCESS.bus, which halts further transmission
from the slave device.
When acting as a slave transmitter or slave
receiver, while PIN=“0”, the chip will suspend
ACCESS.bus transmission by holding the SCL
line low until the PIN bit is set to logic “1”
(inactive). This prevents further data from being
transmitted or received until the current data
byte in S0 has been read (when acting as slave
receiver) or the next data byte is written to S0
(when acting as slave transmitter).
Register S1 Status Section
The read-only section of S1 enables access to
ACCESS.bus status information.
BIT 7: PIN
(Pending Interrupt Not)
This bit is a status flag which is used to
synchronize serial communication and is set to
logic “0” whenever the chip requires servicing.
The PIN bit is normally read in polled
applications to determine when an ACCESS.bus
byte transmission/reception is completed.
PIN bit summary:
Each time a serial data transmission is initiated
(by setting the STA bit in the same register) the
PIN bit will be set to logic “1” automatically
(inactive). When acting as transmitter, PIN is
•
•
•
168
The PIN bit can be used in polled
applications to test when a serial
transmission has been completed. When
the ENI bit is also set, the PIN flag sets the
internal interrupt via the nINT output.
Setting the STA bit (start bit) will set
PIN=“1” (inactive).
In transmitter mode, after successful
transmission of one byte on the
ACCESS.bus the PIN bit will be
•
•
•
•
•
2.
automatically reset to logic “0” (active)
indicating a complete byte transmission.
In transmitter mode, PIN is set to logic “1”
(inactive) each time register S0 is written.
In receiver mode, PIN is set to logic “0”
(inactive) on completion of each received
byte. Subsequently, the SCL line will be
held low until PIN is set to logic “1”.
In receiver mode, when register S0 is read,
PIN is set to logic “1” (inactive).
In slave receiver mode, an ACCESS.bus
STOP condition will set PIN=“0” (active).
PIN= “0” if a bus error (BER) occurs.
BIT 2: AAS
Addressed As Slave bit.
Valid only when
PIN=“0”. When acting as slave receiver, this
flag is set when an incoming address over the
ACCESS.bus matches the value in own address
register S0’ (shifted by one bit) or if the
ACCESS.bus ‘general call’ address (00h) has
been received (‘general call’ is indicated when
AD0 status bit is also set to logic “1”).
BIT 6: Logic 0
BIT 5: STS
When in slave receiver mode, this flag is
asserted when an externally generated STOP
condition is detected (used only in slave receiver
mode).
BIT 1: LAB
Lost Arbitration Bit. This bit is set when, in
multi-master operation, arbitration is lost to
another master on the ACCESS.bus.
BIT 4: BER
Bus error; a misplaced START or STOP
condition has been detected. Resets nBB (to
logic “1”; inactive), sets PIN= “0” (active).
Bit 0: nBB
Bus Busy bit.
This is a read-only flag indicating when the
ACCESS.bus is in use. A “0” indicates that the
bus is busy and access is not possible. This bit
is set/reset (logic “1”/logic “0”) by START/STOP
conditions.
BIT 3: LRB/AD0
Last Received Bit or Address 0 (general call) bit.
This status bit serves a dual function, and is
valid only while PIN= “0”.
1.
ADO; when AAS=“1” (Addressed as slave
condition) the ACCESS.bus controller has
been addressed as a slave. Under this
condition, this bit becomes the AD0 bit and
will be set to logic “1” if the slave address
received was the ‘general call’ (00h)
address, or logic “0” if it was the
ACCESS.bus
controller’s
own
slave
address.
LRB holds the value of the last received bit
over the ACCESS.bus while AAS=“0” (not
addressed as slave). Normally this will be
the value of the slave acknowledgment;
thus checking for slave acknowledgment is
done via testing of the LRB.
169
when this address is received (the value in S0 is
compared with the value in S0’). Note that the
S0 and S0’ registers are offset by one bit;
hence, programming the own address register
S0’ with a value of 55h will result in the value
AAh being recognized as the chip’s
ACCESS.bus slave address.
Own Address Register S0’
When the chip is addressed as slave, this
register must be loaded with the 7-bit
ACCESS.bus address to which the chip is to
respond. During initialization, the own address
register S0’ must be written to, regardless
whether it is later used. The Addressed As
Slave (AAS) bit in status register S1 is set
D7
R/W
Reserved
D6
R/W
Slave
Address
6
D5
R/W
Slave
Address
5
After reset, S0’ has default address 00h.
D4
R/W
Slave
Address
4
D3
R/W
Slave
Address
3
Register S0 acts as serial shift register and read
buffer interfacing to the ACCESS.bus. All read
and write operations to/from the ACCESS.bus
are done via this register. ACCESS.bus data is
always shifted in or out of shift register S0.
D6
R/W
D5
R/W
D1
R/W
Slave
Address
1
D0
R/W
Slave
Address
0
In receiver mode the ACCESS.bus data is
shifted into the shift register until the
acknowledge phase. Further reception of data
is inhibited (SCL held low) until the S0 data shift
register is read.
Data Shift Register S0
D7
R/W
D2
R/W
Slave
Address
2
In the transmitter mode data is transmitted to
the ACCESS.bus as soon as it is written to the
S0 shift register if the serial I/O is enabled
(ESO=1).
D4
R/W
D3
R/W
170
D2
R/W
D1
R/W
D0
R/W
Clock Register S2
ACCESS.bus block. This determines the SCL
clock frequency generated by the chip. The
selection is made via Bits[2:0] (see Table 70).
Register S2 controls the selection of the internal
chip
clock
frequency
used
for
the
D7
D6
D5
D4
R
AB RST
RESERVED
Default = 00 at hard reset and power on reset.
BIT 7: AB_RST
ACCESS.bus Reset Bit.
D3
D2
D1
R/W
See Table 70
D0
entire ACCESS.bus block. Not self-clearing,
must be written high and then written low.
This bit resets the
Table 70 - Internal Clock Rates and ACCESS.bus Data Rates in the FDC37C93xAPM
ACCESS BUS
CLOCK
CLOCK
DATA
NOMINAL
NOMINAL MINIMUM
REGISTER D[2:0]
RATE
RATE
HIGH
LOW
HIGH
000
Off
001
12MHz
50kHz
8µs
12µs
4µs
010
14.318 MHz
60kHz
6.7µs
10.1µs
4µs
011
16MHz
67kHz
6µs
9µs
4µs
100
24MHz
100kHz
4µs
6µs
4µs
101
110
171
ADVANCED CONFIGURATION AND POWER INTERFACE
The SCI enable and status registers are runtime registers which have the same interrupt
event enable and status bits as the SMI
registers. The SCI registers are contained in the
MSC_BLK. Logical Device A will hold the
address pointers to the ACPI power
management register block, PM1_BLK, and the
Miscellaneous register block, MSC_BLK.
The FDC37C93xAPM supports the Advanced
Configuration and Power Interface (ACPI) as
described in this section.
LEGACY/ACPI SELECT CAPABILITY
This capability consists of an SMI/SCI switch
which is required if the system supports both
legacy and ACPI power management models.
This is due to the fact that the system software
for legacy power management consists of the
SMI interrupt handler while for ACPI it consists
of the ACPI driver (SCI interrupt handler). This
support uses Logical Device A at 0x0A to hold
the address pointers to the ACPI power
management register block, PM1_BLK, and the
Miscellaneous register block, MSC_BLK. These
are run-time registers.
Contained in the
MSC_BLK are SCI enable and status registers
which will allow the SMI interrupt events to be
enabled as SCI interrupt events. Included in the
PM1_BLK is an enable bit to allow the SCI
group interrupt to be switched out to SCI
interrupt 13 (pin 97, IRQ13) or routed to one of
the dedicated interrupts.
The SCI pin is the second alternate function
added to pin 97, with the resulting pin having the
multiple functions GP11/IRQIN/IRQ13. The
configuration register for this pin (0xE1) allows
polarity control and selection of open collector
for this interrupt. The nSMI output pin is the
second alternate function of pin 31 in the
FDC37C93xAPM.
The SCI interrupt can be routed to any of the
dedicated interrupt request pins, IRQ[1,3:15].
The SCI interrupt is active low open collector for
all of these IRQ pins. Note that the SCI
interrupt is the only one routed to IRQ13 and its
polarity and output type is selected through
configuration register 0xE1.
The software power management events (those
that generate an SMI in legacy mode and an
SCI in ACPI mode) are controlled by the
EN_SMI and SCI_EN bits. For legacy power
management, the EN_SMI bit is used; if set, it
routes the power management events to the
SMI interrupt logic.
For ACPI power
management, the SCI_EN bit is used; if set, it
routes the power management events to the SCI
interrupt logic.
GLOBAL STATUS AND BIOS STATUS
The SCI enable bit, SCI_EN, is located in the
PM1_CNTRL register, bit 0. This bit is used in
conjunction with EN_SMI, bit 7 of the SMI
enable register 2, to enable either SCI or SMI (or
both).
The BIOS_RLS bit is used by the BIOS to raise
an event to the ACPI software. GBL_EN and
GBL_STS are the corresponding enable and
status bits used by ACPI software to control its
ability to receive SCI events. Setting BIOS_RLS
sets GBL_STS.
If GBL_EN is set and
BIOS_RLS is set an SCI is raised. BIOS_RLS is
Figure 13 shows the process of generating an
interrupt from SMI to SCI and SCI to SMI. This
figure shows the bits involved in this process.
The GBL_EN, GBL_STS and GBL_RLS bits are
located in the PM1_BLK registers.
The
BIOS_RLS, BIOS_EN and BIOS_STS bits are
located in the MISC_BLK registers. These bits
are described below.
172
status bits used by the BIOS to control its ability
to receive ACPI events. Setting GBL_RLS sets
BIOS_STS. If BIOS_EN is set and GBL_RLS
is set an SMI is raised. GBL_RLS is set by
writing a “1” to its bit location; it is cleared by
writing a “1” to the BIOS_STS bit. Writing a “0”
to GBL_RLS has no effect. Writing a “0” to
BIOS_STS has no effect.
set by writing “1” to its bit location; it is cleared
by writing a “1” to the GBL_STS bit. Writing a
“0” to BIOS_RLS has no effect. Writing a “0” to
GBL_STS has no effect.
The GBL_RLS bit is used by the ACPI software
to raise an event to the BIOS. BIOS_EN and
BIOS_STS are the corresponding enable and
SMI to SCI
Clears
GBL_STS
BIOS_RLS
To SCI Logic
GBL_EN
SCI to SMI
Clears
BIOS_STS
GBL_RLS
To SMI Logic
BIOS_EN
SYMBOL
DEFINITION
Enable bit. Software writing this bit HIGH or LOW will result in the bit
being read as HIGH or LOW.
Sticky Status Bit. This bit is set by a hardware signal assertion HIGH.
Cleared by software writing a one to its bit position.
Latched on trailing edge of write strobe.
FIGURE 13 - PROCESS OF GENERATING AN INTERRUPT FROM SMI TO SCI AND SCI TO SMI
173
Setting BM_CNTRL sets BM_STS. If BM_RLD
is set and BM_CNTRL is set, an SCI is raised.
BM_CNTRL is set by writing a 1 to its bit
location; it is cleared by writing a “1” to the
BM_STS bit. Writing a “0” to BM_CNTRL has no
effect. Writing a “0” to BM_STS has no effect.
Bus Master
The Bus Master event logic is shown in Figure
14. The BM_RLD and BM_STS bits are located
in the PM1_BLK and BM_CNTRL is located in
the MSC_BLK. These bits are described below.
C lears
BM_STS
BM_CNTRL
SCI
BM_RLD
FIGURE 14 - BUS MASTER SCI EVENT LOGIC
174
extend the number of bits in the timer, the power
management timer generates an SCI interrupt (if
enabled) when the last bit of the timer changes
from 0 to 1 or 1 to 0. The implementation also
includes a timer enable bit and a timer status
bit. Three additional registers are used to read
the timer value. Figure 15 shows the power
management timer functional diagram.
POWER MANAGEMENT TIMER
This is a 24-bit free running timer that is
required for ACPI compliance.
The power
management timer provides an accurate time
function while the system is in the working state.
This feature is a 24-bit counter which runs off of
a 3.579545 MHz clock. To allow software to
TMR_ON_OFF
TMR_STS
24-bit
Counter
TMR_PME
3.5795454MHz
24
TMR_EN
TMR_VAL
FIGURE 15 - POWER MANAGEMENT TIMER
This circuit has an enable/disable bit to turn the
timer on/off (TMR_ON_OFF, MSC_EN Register,
bit 1). The default of this bit is disabled (off). It
also has a status bit, TMR_STS (PM1_STS
register, bit 0), which is set when the timer
changes from 0 to 1 or 1 to 0 and is cleared by
writing a 1 to its bit location (writing a 0 has no
effect). In addition, it has a bit (TMR_EN,
PM1_EN register, bit 0) to enable the power
management event, TMR_PME, as an SCI
event. The default of this enable/disable bit is
disabled.
The three bytes used to read the 24 bit timer
value, TMR_VAL, are located in the PM1_TMR
register at bits 0-23. Note: Reading the lower
byte of the timer value latches the value in the
other 2 bytes. Reading any byte other than the
lower byte first won’t latch the other 2 bytes, and
the data read will be the previous latched data.
175
with events (which have an associated interrupt
status and enable bits, and sometimes an
associated control function) and control
features. The status registers illustrate what
defined function is requesting ACPI interrupt
services (SCI). Any status bit in the ACPI
specification has the following attributes:
POWER BUTTON OVERRIDE EVENT
The power button has an override event as
required for ACPI compliance. See the Soft
Power Management Section. If the user presses
the power button for more than four seconds
while the system is in the working state, a
hardware event is generated and the system will
transition to the off state. There are status and
enable bits associated with this feature in the
PM1_BLK registers.
A.
Status bits are only set through some
defined “hardware event”.
B. Unless otherwise noted, Status bits are
cleared by writing a “HIGH” to that bit
position and upon VTR POR. Writing a “0”
has no effect.
C. Status bits only generate interrupts while
their associated bits in the enable register
are set.
D. Function bit positions in the status register
have the same bit position in the enable
register (there are exceptions to this rule;
special status bits have no enables).
RTC ALARM
The ACPI specification requires that the RTC
alarm generate a hardware wake-up event from
the sleeping state. The extended RTC alarm 2
event can be enabled as both an SMI and an
SCI event.
There is a bit in the SMI Enable Register 2 and
the SMI Status Register 2 to enable the RTC
alarm 2 event as an SMI interrupt and to read its
status. The status bit is set when the RTC
generates an alarm event and is cleared by
writing a “1” to this bit (writing a “0” has no
effect). When the RTC generates an alarm
event, the RTC_STS bit will be set. If the
RTC_EN bit is set, an RTC hardware power
management event will be generated.
The
RTC_EN bit will be located at bit 6 of the SMI
Enable Register 2, Logical Device 8, 0xB5. The
RTC_STS bit will be located at bit 6 of the SMI
Status Register 2, Logical Device 8, 0xB7.
Note that this implies that if the respective
enable bit is reset and the hardware event
occurs, the respective status bit is set, however
no interrupt is generated until the enable bit is
set. This allows software to test the state of the
event (by examining the status bit) without
necessarily generating an interrupt. There is a
special class of status bits that have no
respective enable bit; these are called out
specifically, and the respective enable bit in the
enable register is marked as reserved for these
special cases.
The enable registers allow the setting of the
status bit to generate an interrupt. As a general
rule, there is an enable bit in the enable register
for every status bit in the status register. The
control register provides special controls for the
associated event, or special control features that
are not associated with an interrupt event. The
ordering of a register block is the status
registers, followed by enable registers, followed
by control registers.
For SCI, the RTC_STS and RTC_EN bits are in
the PM1_STS and PM1_EN registers.
ACPI REGISTER BLOCK DESCRIPTION
The ACPI register model consists of a number
of fixed register blocks that perform designated
functions. A register block consists of a number
of registers that perform Status, Enable and
Control functions. The ACPI specification deals
176
new registers are to be powered by VTR. Table
71C shows the block size and range of base
addresses for each block.
Table 71A and 71B list the PM1 and
MSCregister blocks and the locations of the
registers contained in these blocks. All of these
Table 71A - PM1 Register Block
REGISTER
SIZE
ADDRESS
PM1_STS 1
8
<PM1_BLK>
PM1_STS 2
8
<PM1_BLK>+1h
PM1_EN 1
8
<PM1_BLK>+2h
PM1_EN 2
8
<PM1_BLK>+3h
PM1_CNTRL 1
8
<PM1_BLK>+4h
PM1_CNTRL 2
8
<PM1_BLK>+5h
Reserved
8
<PM1_BLK>+6h
Reserved
8
<PM1_BLK>+7h
PM1_TMR 1
8
<PM1_BLK>+8h
PM1_TMR 2
8
<PM1_BLK>+9h
PM1_TMR 3
8
<PM1_BLK>+Ah
PM1_TMR 4
8
<PM1_BLK>+Bh
Table 71B - MSC Register Block
REGISTER
SIZE
ADDRESS
SCI_STS 1
8
<MSC_BLK>
SCI_STS 2
8
<MSC_BLK>+1h
SCI_EN 1
8
<MSC_BLK>+2h
SCI_EN 2
8
<MSC_BLK>+3h
MSC_STS
8
<MSC_BLK>+4h
Reserved
8
<MSC_BLK>+5h
MSC_EN
8
<MSC_BLK>+6h
MSC_CNTRL
8
<MSC_BLK>+7h
Table 71C - Register Block Attributes
BLOCK NAME
BLOCK SIZE
BASE ADDRESS RANGE
PM1_BLK
16
0-FFFF
MSC_BLK
8
0-FFFF
177
Power Management 1 Register Block (PM1_BLK)
The registers in this block are powered by VTR.
Power Management 1 Status Register 1 (PM1_STS 1)
Register Location: <PM1_BLK> System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1-3
4
5
6-7
Table 72 - Power Management 1 Status Register 1
NAME
DESCRIPTION
TMR_STS
This is the timer status bit. This bit gets set any time bit 23 of the 24
bit counter changes (whenever the MSB changes from low to high or
high to low). Note: bits are counted from 0 to 23. While TMR_EN
and TMR_STS are set a power management event is raised. Note:
This bit is only set by hardware and is reset by software writing a “1”
to this bit position and by VTR POR. Writing a “0” has no effect.
Reserved
Reserved.
BM_STS
This is the bus master status bit. Cleared by VTR POR, and writing
a “1” to this bit position (writing a “0” has no effect). Writing a “1” to
this bit also clears BM_CNTRL.
BM_CNTRL, bit 1 of the
MSC_CNTRL register, sets this bit.
GBL_STS
The global status bit. This bit is set when BIOS_RLS is set. Setting
BIOS_RLS will also raise an SCI if GBL_EN is set. This bit is only
set by hardware and is reset by software writing a “1” to this bit
position and by VTR POR. Writing a “0” has no effect. Writing a “1”
to this bit also clears BIOS_RLS.
Reserved
Reserved. These bits always return a value of “0”.
178
Power Management 1 Status Register 2 (PM1_STS 2)
Register Location: <PM1_BLK>+1h System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
Table 73 - Power Management 1 Status Register 2
NAME
DESCRIPTION
PWRBTN_ST
This bit is set when the Button_In signal is asserted. In the system
S
working state, while PWRBTN_EN and PWRBTN_STS are both set,
an SCI interrupt event is raised. In the sleeping state, while
PWRBTN_EN and PWRBTN_STS are both set a wake-up event is
generated (Note 2). This bit is only set, by hardware and is reset by
software writing a “1” to this bit position, by VTR POR. Writing a 0
has no effect. It is also reset as follows: If PWRBTNOR_EN is set,
and if the Button_In signal is held asserted for more than four
seconds, then this bit is cleared, the PWRBTNOR_STS bit is set
and the system will transition into the soft off state (nPowerOn
floats). Note: The implementation of the PWRBTN_STS and
PWRBTN_EN as described here which requires that PWRBTN_EN
be set for the button to generate a wake-up event is redundant
relative to our present implementation of Button_In where pressing
the button will always wake the machine (i.e., activate nPowerOn).
1
Reserved
Reserved.
2
RTC_STS
This bit is set when the RTC generates an alarm 2. Additionally if
the RTC_EN bit is set then the setting of the RTC_STS bit will
generate an SCI. (See Note)
3
PWRBTNOR_
This bit is set when the power switch over-ride function is set: If
STS
PWRBTNOR_EN is set, and if the Button_In signal is held asserted
for more than four seconds. Hardware is also required to reset the
PWRBTN_STS when issuing a power switch over-ride function.
(See Note)
4-6
Reserved
Reserved. These bits always return a value of “0”.
7
WAK_STS
This bit is set when the system is in the suspended state and an
enabled resume event occurs. This bit is set on the high-to-low
transition of nPowerOn. It is cleared by writing a 1 to its bit location
when nPowerOn is active. Upon setting this bit, the suspend/resume
state machine will transition the system to the on state. (See Note)
Note: This bit is only set by hardware and is reset by software writing a “1” to this bit position and by
VTR POR. Writing a “0” has no effect.
BIT
0
179
Power Management 1 Enable Register 1 (PM1_EN 1)
Register Location:
<PM1_BLK>+2 System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1-4
5
6-7
Table 74 - Power Management 1 Enable Register 1
NAME
DESCRIPTION
TMR_EN
This is the timer interrupt enable bit. When this bit is set, then, an
SCI event is generated any time the TMR_STS bit is set. When this
bit is reset, then no interrupt is generated when the TMR_STS bit is
set.
Reserved
Reserved. These bits always return a value of “0”.
GBL_EN
The global enable bit. When both the GBL_EN and the GBL_STS
are set, an SCI is raised.
Reserved
Reserved.
Power Management 1 Enable Register 2 (PM1_EN 2)
Register Location:
<PM1_BLK>+3 System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1
2
3-7
Table 75 - Power Management 1 Enable Register 2
NAME
DESCRIPTION
PWRBTN_EN This bit is used to enable the assertion of the Button_In to generate
an SCI or wake-up event. The PWRBTN_STS bit is set any time the
Button_In signal is asserted. The enable bit does not have to be set
to enable the setting of the PWRBTN_STS bit by the assertion of the
Button_In signal.
Reserved
Reserved.
RTC_EN
This bit is used to enable the setting of the RTC_STS bit to generate
an SCI. The RTC_STS bit is set any time the RTC generates an
alarm 2.
Reserved
Reserved. These bits always return a value of “0”.
180
Power Management 1 Control Register 1 (PM1_CNTRL 1)
Register Location:
<PM1_BLK>+4 System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1
2
3-7
Table 76 - Power Management 1 Control Register 1
DESCRIPTION
When this bit is set, then the SCI enabled power management events
will generate an SCI interrupt. When this bit is reset, power
management events will not generate an SCI interrupt.
BM_RLD
When set, this bit allows the generation of a bus master request to
cause any processor in the “soft off” state (nPowerOn floats) to
transition to the working state (nPowerOn active). When this bit is
reset, the generation of a bus master request does not affect any
processor in the “soft off” state. If this bit is set and BM_CNTRL is
set, an SCI is raised.
GBL_RLS
The global release bit. This bit is used by the ACPI software to raise
an event to the BIOS software. BIOS software has corresponding
enable and status bits to control its ability to receive ACPI events.
Setting GBL_RLS sets BIOS_STS, and, if BIOS_EN is set, generates
an SMI. Cleared by writing a “1” to BIOS_STS (writing a “0” has no
effect).
Reserved
Reserved. These bits always return a value of “0”.
NAME
SCI_EN
Power Management 1 Control Register 2 (PM1_CNTRL 2)
Register Location:
<PM1_BLK>+5 System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1
2-7
Table 77 - Power Management 1 Control Register 2
NAME
DESCRIPTION
Reserved
Reserved. This field always returns “0”.
PWRBTNOR_E
This bit controls the power button over-ride function. When set, then
N
any time the Button_In signal is asserted for more than four seconds
the system will transition to the off state. When a power button override event occurs, the logic should clear the PWRBTN_STS bit, and
set the PWRBTNOR_STS bit.
Reserved
Reserved. This field always returns “0”.
181
Power Management 1 Timer 1 (PM1_TMR 1)
Register Location:
<PM1_BLK>+8h System I/O Space
Default Value:
00h on VTR POR and RESET_DRV
Attribute:
Read-Only
Size:
8 bits
BIT
0-7
NAME
TMR_VAL
Table 78 - Power Management 1 Timer 1
DESCRIPTION
This read-only field returns the first byte of the running count of the
power management timer. Note: Reading this byte latches the other
two bytes. This is a 24-bit counter that runs off a 3.579545 MHz
clock, and counts while in the working system state. The timer is reset
to an initial value of “0” during a RESET_DRV or VTR POR and then
continues counting until the 14.31818 MHz input to the chip is
stopped. If the 14.31818 MHz clock is restarted without a
RESET_DRV or VTR POR, then the counter will continue counting
from where it stopped. Any time bit 23 of the timer changes state
(goes from LOW to HIGH or HIGH to LOW), the TMR_STS bit is set.
If the TMR_EN bit is set an SCI interrupt is also generated.
Power Management 1 Timer 2 (PM1_TMR 2)
Register Location:
<PM1_BLK>+9h System I/O Space
Default Value:
00h on VTR POR and RESET_DRV
Attribute:
Read-Only
Size:
8 bits
BIT
0-7
NAME
TMR_VAL
Table 79 - Power Management 1 Timer 2
DESCRIPTION
This read-only field returns the second byte of the running count of the
power management timer. This is a 24-bit counter that runs off a
3.579545 MHz clock and counts while in the working system state.
The timer is reset to an initial value of “0” during a RESET_DRV or
VTR POR and then continues counting until the 14.31818 MHz input
to the chip is stopped. If the 14.31818 MHz clock is restarted without a
RESET_DRV or VTR POR, then the counter will continue counting
from where it stopped. Any time bit 23 of the timer changes state
(goes from LOW to HIGH or HIGH to LOW), the TMR_STS bit is set.
If the TMR_EN bit is set an SCI interrupt is also generated.
182
Power Management 1 Timer 3 (PM1_TMR 3)
Register Location:
<PM1_BLK>+Ah System I/O Space
Default Value:
00h on VTR POR and RESET_DRV
Attribute:
Read-Only
Size:
8 bits
BIT
0-7
NAME
TMR_VAL
Table 80 - Power Management 1 Timer 3
DESCRIPTION
This read-only field returns the third byte of the running count of the
power management timer. This is a 24-bit counter that runs off a
3.579545 MHz clock and counts while in the working system state.
The timer is reset to an initial value of “0” during a RESET_DRV or
VTR POR and then continues counting until the 14.31818 MHz input
to the chip is stopped. If the 14.31818 MHz clock is restarted without a
RESET_DRV or VTR POR, then the counter will continue counting
from where it stopped. Any time bit 23 of the timer changes state
(goes from LOW to HIGH or HIGH to LOW), the TMR_STS bit is set.
If the TMR_EN bit is set an SCI interrupt is also generated.
Power Management 1 Timer 4 (PM1_TMR 4)
Register Location:
<PM1_BLK>+Bh System I/O Space
Default Value:
00h on VTR POR and RESET_DRV
Attribute:
Read-Only
Size:
8 bits
BIT
0-7
NAME
Reserved
Table 81 - Power Management 1 Timer4
DESCRIPTION
Reserved.
183
Miscellaneous Block (MSC_BLK)
The registers in this block are powered by VTR.
SCI Status Register 1 (SCI_STS1) This register is used to read the status of the SCI inputs.
Register Location:
<MSC_BLK>+0h System I/O Space
Default Value:
N/A (Status Bits Cleared at Source)
Attribute:
Read Only
Size:
8 bits
BIT
0
1
2
3
4
5
6
7
NAME
IDE1
PINT
U2INT
U1INT
FINT
GPINT2
GPINT1
WDT
Table 82 - SCI Status Register 1
DEFINITION
IDE Interrupt Status. Cleared at source.
Parallel Port Interrupt Status. Cleared at source.
UART 2 Interrupt Status. Cleared at source.
UART 1 Interrupt Status. Cleared at source.
Floppy Disk Controller Interrupt Status. Cleared at source.
Group Interrupt 2 Status. Cleared at source.
Group Interrupt 1 Status. Cleared at source.
Watch Dog Timer Status. Cleared at source.
SCI Status Register 2 (SCI_STS2) This register is used to read the status of the SCI inputs.
Register Location:
<MSC_BLK>+1h System I/O Space
Default Value:
Bits 2, 3 Cleared on VTR POR, Others N/A
Attribute:
Read/Write (Bits 0,1,4-7 are Read Only) (Note 0)
Size:
8 bits
BIT
0
1
2
NAME
MINT
KINT
IRINT
3
BINT
4
5
6
P12
ABINT
Reserved
7
Reserved
Table 83 - SCI Status Register 2
DEFINITION
Mouse Interrupt. Cleared at source.
Keyboard Interrupt. Cleared at source.
IR Interrupt. This bit is set by a transition on the IR pin (IRDX2 or
GP12 as selected in CR L5-F1-B6 i.e., after the MUX). Cleared by
writing a “1” to this bit location (writing a “0” has no effect). Note:
This bit is cleared by VTR POR.
Button Interrupt. This bit is set when the DELAY counter is started.
Cleared by writing a “1” to this bit location (writing a 0 has no effect).
Note: This bit is cleared by VTR POR.
8042 P1.2. Cleared at source.
Access.bus Interrupt. Cleared at source.
Reserved. This bit always returns “0”. Note: RTC_STS is located in
the PM1_STS register.
Reserved. This bit always returns zero.
184
SCI Enable Register 1 (SCI_EN1). This register is used to enable the different interrupt sources onto
the group SCI output, and the group SCI output onto an IRQ pin for SCI.
Register Location:
Default Value:
Attribute:
Size:
BIT
0
1
2
3
4
5
6
7
<MSC_BLK>+2h System I/O Space
00h on VTR POR
Read/Write (Note 0)
8 bits
NAME
EN_IDE1
EN_PINT
EN_U2INT
EN_U1INT
EN_FINT
EN_GPINT2
EN_GPINT1
EN_WDT
Table 84 - SCI Enable Register 1
DEFINITION
IDE Interrupt Enable. 1=Enable, 0=Disable
Parallel Port Interrupt Enable. 1=Enable, 0=Disable
UART 2 Interrupt Enable. 1=Enable, 0=Disable
UART 1 Interrupt Enable. 1=Enable, 0=Disable
Floppy Disk Controller Interrupt Enable. 1=Enable, 0=Disable
Group Interrupt 2 Enable. 1=Enable, 0=Disable
Group Interrupt 1 Enable. 1=Enable, 0=Disable
Watch Dog Timer Enable. 1=Enable, 0=Disable
SCI Enable Register 2 (SCI_EN2). This register is used to enable the different interrupt sources onto
the group SCI output, and the group SCI output onto an IRQ pin for SCI.
Register Location:
Default Value:
Attribute:
Size:
<MSC_BLK>+3h System I/O Space
00h on VTR POR
Read/Write (Note 0)
8 bits
NAME
0
1
2
3
4
5
6
REG INDEX
EN_MINT
EN_KINT
EN_IRINT
EN_BINT
EN_P12
EN_ABINT
Reserved
7
Reserved
Table 85 - SCI Enable Register 2
DEFINITION
Mouse Interrupt. 1=Enable, 0=Disable
Keyboard Interrupt. 1=Enable, 0=Disable
IR Interrupt. 1=Enable, 0=Disable
Button Interrupt. 1=Enable, 0=Disable
8042 P1.2 Interrupt. 1=Enable, 0=Disable
Access.bus Interrupt. 1=Enable, 0=Disable
Reserved. This bit always returns “0”. Note: RTC_EN is located in
the PM1_EN register.
Reserved. This bit always returns zero. Note SCI_EN is located in
the PM1_CNTRL register.
185
Miscellaneous Status Register (MSC_STS)
Register Location:
<MSC_BLK>+4h System I/O Space
Default Value:
02h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
NAME
BIOS_STS
1
VTRP_STS
2
EETI1_STS
3
EETI2_STS
4
EETI3_STS
5-7
Reserved
Table 86 - Miscellaneous Status Register
DEFINITION
This bit is set when GBL_RLS is set. Setting GBL_RLS will also
raise an SMI if BIOS_EN is set. This bit is cleared by a writing a “1”
to its bit location (writing a “0” has no effect). Writing a “1” to this bit
also clears GBL_RLS. Note: This bit is cleared by VTR POR
VTR POR Status. This bit is set upon VTRPOR; it is cleared by a
writing a “1” to its bit location (writing a “0” has no effect). Note: This
bit is cleared by VTR POR
Either Edge Triggered Interrupt Input 1 Status. This bit is cleared by
writing a “1” to this bit position (writing a “0” has no effect). Note:
This bit is cleared by VTR POR
Either Edge Triggered Interrupt Input 2 Status. This bit is cleared by
writing a “1” to this bit position (writing a “0” has no effect). Note:
This bit is cleared by VTR POR
Either Edge Triggered Interrupt Input 3 Status. This bit is cleared by
writing a “1” to this bit position (writing a “0” has no effect). Note:
This bit is cleared by VTR POR
Reserved. This bit always returns “0”.
Miscellaneous Enable Register (MSC_EN)
Register Location:
<MSC_BLK>+6h System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1
2-7
Table 87 - Miscellaneous Enable Register
DEFINITION
This bit is used to enable the SMI event. When both the BIOS_EN
and GBL_RLS are set, an SMI is generated.
TMR_ON_OF
This bit is used to turn the power management timer on/off.
F
0=Off, 1=On.
Reserved
Reserved. This bit always returns “0”.
NAME
BIOS_EN
186
Miscellaneous Control Register (MSC_CNTRL)
Register Location:
<MSC_BLK>+7h System I/O Space
Default Value:
00h on VTR POR
Attribute:
Read/Write (Note 0)
Size:
8 bits
BIT
0
1
2-7
Table 88 - Miscellaneous Control Register
DEFINITION
This bit is used by the BIOS to raise an event to the ACPI software.
ACPI software has corresponding enable and status bits to control
its ability to receive SCI events. Set by writing “1” to this bit
location. Setting BIOS_RLS sets GBL_STS, and if GBL_EN is set,
generates an SCI. Writing “0” has no effect. Cleared by writing a “1”
to the GBL_STS bit (writing a “0” has no effect).
BM_CNTRL
This bit is used to set the BM_STS bit and generate an SCI.
BM_STS is set by writing “1” to this bit location. Writing “0” has no
effect. It is cleared by writing a “1” to the BM_STS bit (writing a “0”
has no effect). If BM_RLD is set, setting this bit also raises an SCI.
Reserved
Reserved. This bit always returns “0”.
NAME
BIOS_RLS
Note: all bits described as "reserved" in writeable registers must be written with the value 0 when the
register is written.
187
CONFIGURATION
The BIOS uses these configuration ports to
initialize the logical devices at POST. The
INDEX and DATA ports are only valid when the
FDC37C93xAPM is in Configuration Mode.
The configuration of the FDC37C93xAPM is
very flexible and is based on the configuration
architecture implemented in typical Plug-andPlay components. The FDC37C93xAPM is
designed for motherboard applications in which
the resources required by their components are
known. With its flexible resource allocation
architecture, the FDC37C93xAPM allows the
BIOS to assign resources at POST.
The SYSOPT pin is latched on the falling edge
of the RESET_DRV or on VCC Power On Reset
to determine the configuration register's base
address. The SYSOPT pin is used to select the
CONFIG PORT's I/O address at power-up.
Once powered up the configuration port base
address can be changed through configuration
registers CR26 and CR27. The SYSOPT pin
is a hardware configuration pin which is
shared with the nRTS1 signal on pin 148.
During reset this pin is a weak active low signal
which sinks 30µA. Note: All I/O addresses are
qualified with AEN.
SYSTEM ELEMENTS
Primary Configuration Address Decoder
After a hard reset (RESET_DRV pin asserted) or
VCC Power On Reset the FDC37C93xAPM is in
the Run Mode with all logical devices disabled.
The logical devices may be configured through
two standard Configuration I/O Ports (INDEX
and DATA) by placing the FDC37C93xAPM
into Configuration Mode.
The INDEX and DATA ports are effective only
when the chip is in the Configuration State.
Table 89 - Configuration Port I/O Address
SYSOPT= 0
PORT NAME
(Pull-down resistor)
SYSOPT= 1
Refer to Note 1
(10K Pull-up resistor)
CONFIG PORT (Note 2)
0x03F0
0x0370
INDEX PORT (Note 2)
DATA PORT
Note 1:
Note 2:
0x03F0
0x0370
INDEX PORT + 1
TYPE
Write
Write
Read/Write
If using TTL RS232 drivers use 1K pull-down. If using CMOS RS232 drivers use
10K pull-down.
The configuration port base address can be relocated through CR26 and CR27.
Entering the Configuration State
The device enters the Configuration State when
the following Config Key is successfully written
to the CONFIG PORT.
Exiting the Configuration State
The device exits the Configuration State when
the following Config Key is successfully written
to the CONFIG PORT.
Config Key = < 0x55 >
Config Key = < 0xAA >
188
CONFIGURATION SEQUENCE
Exit Configuration Mode
To program the configuration registers, the
following sequence must be followed:
1. Enter Configuration Mode
2. Configure the Configuration Registers
3. Exit Configuration Mode.
To exit the Configuration State the system
writes 0xAA to the CONFIG PORT. The chip
returns to the RUN State. Note: Only two states
are defined (Run and Configuration). In the Run
State the chip will always be ready to enter the
Configuration State.
Enter Configuration Mode
Programming Example
To
place
the
chip
into
the
Configuration State the Config Key is sent to
the chip's CONFIG PORT. The config key
consists of a single write of 0x55 data to the
CONFIG PORT. Once the initiation key is
received correctly the chip enters into the
Configuration State (the auto Config ports are
enabled).
The following is an example of a configuration
program in Intel 8086 assembly language.
;--------------------------------------------------.
; ENTER CONFIGURATION MODE
|
;--------------------------------------------------'
MOV DX,3F0H
MOV AX,055H
OUT DX,AL
;--------------------------------------------------.
; CONFIGURE REGISTER CRE0,
|
; LOGICAL DEVICE 8
|
;--------------------------------------------------'
MOV DX,3F0H
MOV AL,07H
OUT DX,AL ; Point to LD# Config Reg
MOV DX,3F1H
MOV AL, 08H
OUT DX,AL ; Point to Logical Device 8
;
MOV DX,3F0H
MOV AL,E0H
OUT DX,AL ; Point to CRE0
MOV DX,3F1H
MOV AL,02H
OUT DX,AL ; Update CRE0
;-------------------------------------------------.
; EXIT CONFIGURATION MODE
|
;-------------------------------------------------'
MOV DX,3F0H
MOV AX,0AAH
OUT DX,AL
Configuration Mode
The system sets the logical device information
and activates desired logical devices through
the INDEX and DATA ports. In configuration
mode, the INDEX PORT is located at the
CONFIG PORT address and the DATA PORT is
at INDEX PORT address + 1.
The desired configuration registers are accessed
in two steps:
a. Write the index of the Logical Device
Number Configuration Register (i.e., 0x07) to
the INDEX PORT and then write the number
of the desired logical device to the DATA
PORT
b. Write the address of the desired
configuration register within the logical
device to the INDEX PORT and then write or
read the configuration register through the
DATA PORT.
Note: if accessing the Global Configuration
Registers, step (a) is not required.
189
Notes: 1. HARD RESET: RESET_DRV pin asserted
2. SOFT RESET: Bit 0 of Configuration Control register set to one
3. All host accesses are blocked for 500µs after Vcc POR (see Power-up Timing Diagram)
Table 90 - Configuration Registers
HARD RESET
SOFT
/ VCC POR
VTR POR
RESET
CONFIGURATION REGISTER
GLOBAL CONFIGURATION REGISTERS
INDEX
TYPE
0x02
W
0x00
0x03
R/W
0x07
R/W
0x20
0x00
Config Control
0x03
n/a
Index Address
0x00
0x00
Logical Device Number
R
0x30
0x30
Device ID - hard wired
0x21
R
0x01
0x01
Device Rev - hard wired
0x22
R/W
0x00
0x00
Power Control
0x23
R/W
0x00
n/a
Power Mgmt
0x24
R/W
0x04
n/a
OSC
0x26
R/W
n/a
Configuration Port Address Byte 0
0x27
R/W
n/a
Configuration Port Address Byte 1
0x00
0x28
R/W
Sysopt=0: 0xF0
Sysopt=1: 0x70
Sysopt=0: 0x03
Sysopt=1: 0x03
0x00
0x2D
R/W
n/a
n/a
TEST 1
0x2E
R/W
n/a
n/a
TEST 2
0x2F
R/W
0x00
n/a
TEST 3
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x03,
0xF0
0x03,
0xF0
Primary Base I/O Address
0x70
R/W
0x06
0x06
Primary Interrupt Select
0x74
R/W
0x02
0x02
DMA Channel Select
0xF0
R/W
0x0E
n/a
FDD Mode Register
0xF1
R/W
0x00
n/a
FDD Option Register
0xF2
R/W
0xFF
n/a
FDD Type Register
0xF4
R/W
0x00
n/a
FDD0
0xF5
R/W
0x00
n/a
FDD1
Clock Mask Register
LOGICAL DEVICE 0 CONFIGURATION REGISTERS (FDD)
190
Table 90 - Configuration Registers
HARD RESET
SOFT
/ VCC POR
VTR POR
RESET
CONFIGURATION REGISTER
LOGICAL DEVICE 1 CONFIGURATION REGISTERS (IDE1)
INDEX
TYPE
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x01,
0xF0
0x01,
0xF0
Primary Base I/O Address
0x62,
0x63
R/W
0x03,
0xF6
0x03,
0xF6
Second Base I/O Address
0x70
R/W
0x0E
0x0E
Primary Interrupt Select
0xF0
R/W
0x0C
0x0C
HDCS0 Address Decoder
0xF1
R/W
0x00
0x00
HDCS1 Address Decoder
LOGICAL DEVICE 2 CONFIGURATION REGISTERS (IDE2)
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
Primary Base I/O Address
0x62,
0x63
R/W
0x00,
0x00
0x00,
0x00
Second Base I/O Address
0x70
R/W
0x00
0x00
Primary Interrupt Select
0xF0
R/W
0x00
n/a
IDE2 Mode Register
LOGICAL DEVICE 3 CONFIGURATION REGISTERS (Parallel Port)
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
Primary Base I/O Address
0x70
R/W
0x00
0x00
Primary Interrupt Select
0x74
R/W
0x04
0x04
DMA Channel Select
0xF0
R/W
0x3C
n/a
Parallel Port Mode Register
0xF1
R/W
0x00
n/a
Parallel Port Mode Register 2
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
Primary Base I/O Address
0x70
R/W
0x00
0x00
Primary Interrupt Select
0xF0
R/W
0x00
n/a
LOGICAL DEVICE 4 CONFIGURATION REGISTERS (Serial Port 1)
191
Serial Port 1 Mode Register
Table 90 - Configuration Registers
INDEX
HARD RESET
SOFT
TYPE
/ VCC POR
VTR POR
RESET
CONFIGURATION REGISTER
LOGICAL DEVICE 5 CONFIGURATION REGISTERS (Serial Port 2)
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
Primary Base I/O Address
0x70
R/W
0x00
0x00
Primary Interrupt Select
0xF0
R/W
0x00
n/a
Serial Port 2 Mode Register
0xF1
R/W
0x02
n/a
IR Options Register
0xF2
R/W
0x03
n/a
IR Half Duplex Timeout
LOGICAL DEVICE 6 CONFIGURATION REGISTERS (RTC)
0x30
R/W
0x00
0x00
Activate
0x62,
0x63
R/W
0x00,
0x70
0x00,
0x70
Secondary Base Address for RTC
Bank 1 and Bank 2
0x70
R/W
0x00
0x00
0xF0
R/W
0x00
n/a
Real Time Clock Mode Register
Primary Interrupt Select
0xF1
R/W
0x00
n/a
Serial EEPROM Mode Register
0xF2
R/W
0x00
0x00
0xF3
W
n/a
n/a
0xF4
bits[6:0]
R
bit[7]
R/W
0x03
0x03
0xF5
R
n/a
n/a
Read EEPROM Data
0xF6
R
n/a
n/a
Read Status
Serial EEPROM Pointer
Write EEPROM Data
Write Status
LOGICAL DEVICE 7 CONFIGURATION REGISTERS (Keyboard)
0x30
R/W
0x00
0x00
Activate
0x70
R/W
0x00
0x00
Primary Interrupt Select
0x72
R/W
0x00
0x00
Second Interrupt Select
0xF0
R/W
0x00
n/a
KRESET and GateA20 Select
LOGICAL DEVICE 8 CONFIGURATION REGISTERS (Aux I/O)
0x30
R/W
0x00
0x00
Activate
0x60,
R/W
0x00,
0x00
0x00,
Primary Base I/O Address
192
Table 90 - Configuration Registers
HARD RESET
/ VCC POR
SOFT
RESET
0x00
INDEX
0x61
TYPE
VTR POR
0x62,
0x63
R/W
0xB0
R/W
0x00
n/a
Soft Power Enable Register 1
0xB1
R/W
0x80
n/a
Soft Power Enable Register 2
0xB2
R/W
0x00
n/a
Soft Power Status Register 1
0xB3
R/W
0x00
n/a
Soft Power Status Register 2
0xB4
R/W
0x00
n/a
SMI Enable Register 1
0xB5
R/W
0x00
n/a
SMI Enable Register 2
0xB6
R/W
0x00
n/a
SMI Status Register 1
0xB7
R/W
0x00
n/a
SMI Status Register 2
0xB8
R/W
0x00
n/a
Delay 2 Time Set Register
0xC0
R/W
0x01
n/a
GP40
0xC1
R/W
0x01
n/a
GP41
0xC2
R/W
0x00
n/a
GP42
0xC3
R/W
0x00
n/a
GP43
0xC4
R/W
0x00
n/a
GP44
0xC5
R/W
0x01
n/a
GP45
0xC6
R/W
0x01
n/a
GP46
0xC7
R/W
0x01
n/a
GP47
0xC8
R/W
0x01
n/a
GP50
0xC9
R/W
0x80
n/a
GP51
0xCB
R/W
0x01
n/a
GP53
0xCC
R/W
0x01
n/a
GP54
0xD0
R/W
0x01
n/a
GP60
0xD1
R/W
0x01
n/a
GP61
0xD2
R/W
0x01
n/a
GP62
0xD3
R/W
0x01
n/a
GP63
0xD4
R/W
0x01
n/a
GP64
0xD5
R/W
0x01
n/a
GP65
0x00,
0x00
0x00,
0x00
193
CONFIGURATION REGISTER
Second Base I/O Address
Table 90 - Configuration Registers
VTR POR
0x01
SOFT
RESET
n/a
R/W
0x01
n/a
GP67
0xD8
R/W
0x01
n/a
GP70
INDEX
0xD6
TYPE
R/W
0xD7
HARD RESET
/ VCC POR
CONFIGURATION REGISTER
GP66
0xD9
R/W
0x01
n/a
GP71
0xDA
R/W
0x01
n/a
GP72
0xDB
R/W
0x01
n/a
GP73
0xDC
R/W
0x01
n/a
GP74
0xDD
R/W
0x01
n/a
GP75
0xDE
R/W
0x01
n/a
GP76
0xDF
R/W
0x01
n/a
GP77
0xE0
R/W
0x01
n/a
GP10
0xE1
R/W
0x01
n/a
GP11
0xE2
R/W
0x01
n/a
GP12
0xE3
R/W
0x01
n/a
GP13
0xE4
R/W
0x01
n/a
GP14
0xE5
R/W
0x01
n/a
GP15
0xE6
R/W
0x01
n/a
GP16
0xE7
R/W
0x01
n/a
GP17
0xE8
R/W
0x01
n/a
GP20
0xE9
R/W
0x01
n/a
GP21
0xEA
R/W
0x01
n/a
GP22
0xEB
R/W
0x01
n/a
GP23
0xEC
R/W
0x01
n/a
GP24
0xED
R/W
0x01
n/a
GP25
0xEF
R/W
0x00
n/a
GP_INT2
0xF0
R/W
0x00
n/a
GP_INT1
0xF1
R/W
0x00
n/a
GPR_GPW_EN
0xF2
R/W
0x00
n/a
WDT_VAL
0xF3
R/W
0x00
n/a
WDT_CFG
0xF4
R/WNote1
n/a
WDT_CTRL
0x00
194
Table 90 - Configuration Registers
INDEX
0xF6
TYPE
R/W
HARD RESET
/ VCC POR
0x00
SOFT
RESET
n/a
0xF7
R/W
0x00
n/a
GP2
0xF8
R/W
0x00
n/a
GP4
VTR POR
CONFIGURATION REGISTER
GP1
0xF9
R/W
0x00
n/a
GP5
0xFA
R/W
0x00
n/a
GP6
0xFB
R/W
0x00
n/a
GP7
LOGICAL DEVICE 9 CONFIGURATION REGISTERS (ACCESS.bus)
0x30
R/W
0x00
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
Primary Base I/O Address
0x70
R/W
0x00
0x00
Primary Interrupt Select
0x30
R/W
0x00
0x00
Activate
0x60,
R/W
0x00,
0x00,
Primary Base I/O Address
0x00
0x00
PM1_BLK
R/W
0x00,
0x00,
Secondary Base I/O Address
0x00
0x00
MSC_BLK
0x00
0x00
Primary Interrupt Select
LOGICAL DEVICE A CONFIGURATION REGISTERS (ACPI)
0x61 (2)
0x62,
0x63 (2)
0x70
Note 1:
Note 2 :
R/W
This register contains some bits which are read or write only.
Registers 60 and 62 are the high byte; 61 and 63 are the low byte. For example to set
the primary base address to 1234h, write 12h into 60 and 34h into 61.
195
The INDEX PORT is used to select a
configuration register in the chip. The DATA
PORT is then used to access the selected
register. These registers are accessable only in
the Configuration Mode.
Chip - Level (Global) Control/Configuration
Registers [0x00-0x2F]
The chip-level (global) registers lie in the
address range [0x00-0x2F]. The design MUST
use all 8 bits of the ADDRESS Port for register
selection. All unimplemented registers and bits
ignore writes and return zero when read.
Table 91 - Chip Level Registers
REGISTER
ADDRESS
DESCRIPTION
STATE
Chip (Global) Control Registers
0x00 0x01
Config Control
0x02 W
The hardware automatically clears this bit after the
write, there is no need for software to clear the bits.
Bit [0]=1: Soft Reset. Refer to the "Configuration
Registers" table for the soft reset value for each
register.
0x03 R/W
Bit[7]
= 1 Enable GP1, GP2, WDT_CTRL, GP4, GP5,
GP6, GP7, Soft Power and SMI Enable
and Status Register access when not in
configuration mode
= 0 Disable GP1, GP2, WDT_CTRL, GP4, GP5,
GP6, GP7, Soft Power and SMI Enable
and Status Register access when not in
configuration mode (Default)
Bit [6:2]
Reserved - Writes are ignored, reads return 0.
Bits[1:0]
Sets GP index register address, used when in Run
mode (not in Configuration Mode).
= 11 0xEA (Default)
= 10 0xE4
= 01 0xE2
= 00 0xE0
Default = 0x00
on Vcc POR or
Reset_Drv
Index Address
Default = 0x03
on Vcc POR or
Reset_Drv
Reserved - Writes are ignored, reads return 0.
0x04 - 0x06 Reserved - Writes are ignored, reads return 0.
196
C
Table 91 - Chip Level Registers
REGISTER
ADDRESS
DESCRIPTION
STATE
Logical Device #
0x07 R/W
A write to this register selects the current logical
device. This allows access to the control and
configuration registers for each logical device.
Note: the Activate command operates only on the
selected logical device.
C
Default = 0x00
on VCC POR or
Reset_Drv
Card Level
Reserved
0x08 - 0x1F Reserved - Writes are ignored, reads return 0.
Chip Level, SMSC Defined
Device ID
0x20 R
A read-only register which provides
identification. Bits[7:0] = 0x30 when read.
device
C
0x21 R
A read-only register which provides device revision
information. Bits[7:0] = 0x01 when read.
C
0x22 R/W
Bit[0] FDC Power
Bit[1] IDE1 Enable
Bit[2] IDE2 Enable
Bit[3] Parallel Port Power
Bit[4] Serial Port 1 Power
Bit[5] Serial Port 2 Power
Bit[6] ACCESS.bus Power
Bit[7] Reserved (read as 0)
=0
Power off or disabled
=1
Power on or enabled
C
0x23 R/W
Bit[0] FDC
Bit[1] IDE1
Bit[2] IDE2
Bit[3] Parallel Port
Bit[4] Serial Port 1
Bit[5] Serial Port 2
Bit[6:7] Reserved (read as 0)
=0
Intelligent Pwr Mgmt off
=1
Intelligent Pwr Mgmt on
C
Hard wired
= 0x30
Device Rev
Hard wired
= 0x01
Power Control
Default = 0x00.
on Vcc POR or
Reset_Drv hardware
signal.
Power Mgmt
Default = 0x00.
on VCC POR or
Reset_Drv hardware
signal
197
Table 91 - Chip Level Registers
REGISTER
OSC
ADDRESS
DESCRIPTION
STATE
0x24 R/W
Bit[0] 24/48 MHz Clock Select (Pin 35)
=0
24 MHz (Default)
=1
48 MHz
Bit [1] PLL Control
= 0 PLL is on (backward compatible)
= 1 PLL is off
Bit[3:2] OSC
= 01 Osc is on, BRG clock is on.
= 10 Same as above (01) case.
= 00 Osc is on, BRG Clock Enabled.
= 11 Osc is off, BRG clock is disabled.
Bit[5:4] Reserved, set to “0”
Bit[6] 16 Bit Address Qualification
= 0 12 Bit Address Qualification
= 1 16 Bit Address Qualification
(Refer to the 16-bit Address Qualification in
the SMSC Defined Logical Device Configuration
Register, Device 2 section.)
Bit[7] IRQ8 Polarity
= 0 IRQ8 is active high
= 1 IRQ8 is active low
C
Default = 0x04, on
VCC POR or
Reset_Drv hardware
signal.
Chip Level
Vendor Defined
0x25
Reserved - Writes are ignored, reads return 0.
Configuration
Address Byte 0
0x26
Bit[7:1] Configuration Address Bits [7:1]
Bit[0] = 0
See Note 1
C
0x27
Bit[7:0] Configuration Address Bits [15:8]
See Note 1
C
0x28
Mask clocks as defined below.
0= Clock On, 1= Clock Masked (pin tri-states)
Default
=0xF0 (Sysopt=0)
=0x70 (Sysopt=1)
on VCC POR or
Reset_Drv
Configuration
Address Byte 1
Default = 0x03
on VCC POR or
Reset_Drv
Clock Mask
Register
198
Table 91 - Chip Level Registers
REGISTER
ADDRESS
DESCRIPTION
Chip Level
Vendor Defined
0x29 -0x2C
Bit[0] 14.318 MHz Clock Output 1 (Pin 37)
Bit[1] 14.318 MHz Clock Output 2 (Pin 38)
Bit[2] 14.318 MHz Clock Output 3 (Pin 39)
Bit[3] 16 MHz Clock Output (Pin 36)
Bit[4] High Speed Clock Out 24/48 MHz (Pin 35)
Bit[7:5] Reserved - Writes are ignored, reads return
0.
Reserved - Writes are ignored, reads return 0.
TEST 1
0x2D R/W
Test Modes: Reserved for SMSC. Users should not
write to this register; may produce undesired
results.
C
TEST 2
0x2E R/W
Test Modes: Reserved for SMSC. Users should not
write to this register; may produce undesired
results.
C
TEST 3
0x2F R/W
Test Modes: Reserved for SMSC. Users should not
write to this register; may produce undesired
results.
C
Default = 0x00
on VCC POR and
Hard Reset
Default = 0x00, on
VCC POR or
Reset_Drv hardware
signal
STATE
Note 1: To allow the selection of the configuration address to a user defined location, these
Configuration Address Bytes are used. There is no restriction on the address chosen, except that A0
is 0, that is, the address must be on an even byte boundary. As soon as both bytes are changed, the
configuration space is moved to the specified location with no delay (Write byte 0, then byte 1; writing
CR27 changes the base address).
The configuration address is only reset to its default address upon a Hard Reset or VCC POR. The
default configuration address is either 3F0 or 370, as specified by the SYSOPT pin.
This change affects SMSC Mode only.
199
Logical
Device
Configuration/Control
Registers [0x30-0xFF]
logical device and is selected with the Logical
Device # Register (0x07).
Used to access the registers that are assigned
to each logical unit. This chip supports nine
logical units and has nine sets of logical device
registers. The nine logical devices are Floppy,
IDE1, IDE2, Parallel, Serial 1 and Serial 2, Real
Time Clock, Keyboard Controller, and
Auxiliary_I/O. A separate set (bank) of control
and configuration registers exists for each
The INDEX PORT is used to select a specific
logical device register. These registers are then
accessed through the DATA PORT.
The Logical Device registers are accessible only
when the device is in the Configuration State.
The logical register addresses are:
Table 92 - Logical Device Registers
LOGICAL DEVICE
REGISTER
ActivateNote1
ADDRESS
DESCRIPTION
STATE
(0x30)
Bit[7:1] Reserved, set to “0”.
Bit[0]
= 1 Activates the logical device currently
selected through the Logical Device #
register.
=0
Logical device currently selected is
inactive.
Reserved - Writes are ignored, reads return
0.
C
Default = 0x00
on VCC POR or
Reset_Drv
Logical Device Control
(0x31-0x37)
Logical Device Control
(0x38-0x3f)
Vendor Defined - Reserved - Writes are
ignored, reads return 0.
C
Mem Base Addr
(0x40-0x5F)
Reserved - Writes are ignored, reads return
0.
C
I/O Base Addr.
(0x60-0x6F)
C
(see Device Base I/O
Address Table)
0x60,2,... =
addr[15:8]
Registers 0x60 and 0x61 set the base
address for the device. If more than one
base address is required, the second base
address is set by registers 0x62 and 0x63.
Default = 0x00
on VCC POR or
Reset_Drv
0x61,3,... =
addr[7:0]
Refer to Table 91 for the number of base
address registers used by each device.
Unused registers will ignore writes and return
“0” when read.
200
C
Table 92 - Logical Device Registers
LOGICAL DEVICE
REGISTER
ADDRESS
DESCRIPTION
STATE
(0x70,072)
0x70 is implemented for each logical device.
Refer to Interrupt Configuration Register
description. Only the keyboard controller
uses Interrupt Select register 0x72. Unused
register (0x72) will ignore writes and return
zero when read. Interrupts default to edge
high (ISA compatible).
C
(0x71,0x73)
Reserved - not implemented. These register
locations ignore writes and return zero when
read.
(0x74,0x75)
Only 0x74 is implemented for FDC, serial
port 2 and Parallel port.
0x75 is not
implemented and ignores writes and returns
“0” when read. Refer to DMA Channel
Configuration.
32-Bit Memory Space
Configuration
(0x76-0xA8)
Reserved - not implemented. These register
locations ignore writes and return “0” when
read.
Logical Device
(0xA9-0xDF)
Reserved - not implemented. These register
locations ignore writes and return “0” when
read.
C
Logical Device Config.
(0xE0-0xFE)
Reserved - Vendor Defined (see SMSC
defined
Logical
Device
Configuration
Registers)
C
Reserved
C
Interrupt Select
Defaults :
0x70 = 0x00,
on VCC POR or
Reset_Drv
0x72 = 0x00,
on Vcc POR or
Reset_Drv
DMA Channel Select
Default = 0x04
on VCC POR or
Reset_Drv
Reserved
Note 1:
0xFF
C
A logical device will be active and powered up according to the following equation:
DEVICE ON (ACTIVE) = (Activate Bit SET or Pwr/Control Bit SET).
The Logical device's Activate Bit and its Pwr/Control Bit are linked such that setting or clearing one
sets or clears the other. If the I/O Base Addr of the logical device is not within the Base I/O range as
shown in the Logical Device I/O map, then read or write is not valid and is ignored.
201
LOGICAL
DEVICE
NUMBER
0x00
0x01
0x02
Table 93 - I/O Base Address Configuration Register Description
BASE I/O
RANGE
FIXED
LOGICAL REGISTER
(NOTE 1)
BASE OFFSETS
DEVICE
INDEX
FDC
0x60,0x61
[0x100:0x0FF8]
+0 : SRA
(Note 4)
ON 8 BYTE BOUNDARIES +1 : SRB
+2 : DOR
+3 : TSR
+4 : MSR/DSR
+5 : FIFO
+7 : DIR/CCR
IDE1
(Note 4)
IDE2
(Note 4)
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
IDE TASK
+0 : Data Register (16 bit)
+1 : ERRF/WPRE
+2 : Sector Count
+3 : Sector Number
+4 : Cylinder Low
+5 : Cylinder High
+6 : Head,Drive
+7 : Status/Command
0x62,0x63
[0x100:0x0FFF]
ON 1 BYTE BOUNDARIES
IDE MISC AT
+ 0 : Status/Fixed Disk
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
IDE TASK
+0 : Data Register (16 bit)
+1 : ERRF/WPRE
+2 : Sector Count
+3 : Sector Number
+4 : Cylinder Low
+5 : Cylinder High
+6 : Head,Drive
+7 : Status/Command
0x62,0x63
[0x100:0x0FFF]
ON 1 BYTE BOUNDARIES
IDE MISC AT
+ 0 : Status/Fixed Disk
202
LOGICAL
DEVICE
NUMBER
0x03
Table 93 - I/O Base Address Configuration Register Description
BASE I/O
RANGE
FIXED
LOGICAL REGISTER
(NOTE 1)
BASE OFFSETS
DEVICE
INDEX
+0 : Data|ecpAfifo
Parallel
0x60,0x61
[0x100:0x0FFC]
Port
ON 4 BYTE BOUNDARIES +1 : Status
+2 : Control
(EPP not supported)
+3 : EPP Address
or
+4 : EPP Data 0
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES +5 : EPP Data 1
+6 : EPP Data 2
(all modes supported,
EPP is only available when +7 : EPP Data 3
the base address is on an 8- +400h : cfifo|ecpDfifo|tfifo
|cnfgA
byte boundary)
+401h : cnfgB
+402h : ecr
0x04
Serial Port
1
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
+0 : RB/TB|LSB div
+1 : IER|MSB div
+2 : IIR/FCR
+3 : LCR
+4 : MSR
+5 : LSR
+6 : MSR
+7 : SCR
0x05
Serial Port
2
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
+0 : RB/TB|LSB div
+1 : IER|MSB div
+2 : IIR/FCR
+3 : LCR
+4 : MSR
+5 : LSR
+6 : MSR
+7 : SCR
0x06
RTC
n/a
Not Relocatable
Fixed Base Address: 70,71
[0x100:0xFFE]
ON 2 BYTE BOUNDARIES
Not Relocatable
Fixed Base Address: 60,64
+0: Index Register
+1: Data Register
+0: Index Register
+1: Data Register
+0 : Data Register
+4 : Command/Status Reg.
0x62,0x63
0x07
KYBD
n/a
0x08
Aux. I/O
0x60,0x61
[0x00:0xFFF]
ON 1 BYTE BOUNDARIES
+0 : GPR
0x62,0x63
[0x00:0xFFF]
ON 1 BYTE BOUNDARIES
+0 : GPW
203
LOGICAL
DEVICE
NUMBER
0x09
0x0A
Table 93 - I/O Base Address Configuration Register Description
BASE I/O
RANGE
FIXED
LOGICAL REGISTER
(NOTE 1)
BASE OFFSETS
DEVICE
INDEX
Access.
0x60,0x61
[0x00:0x0FFC]
+0 : Control/Status Reg
Bus
ON 4 BYTE BOUNDARIES +1 : Own Address Reg
+2 : Data Reg
+3 : Clock Register
ACPI
0x60,0x61
0x62,0x63
Note 1:
Note 2:
+0: PM1_STS1
[0x0000:0xFFFF]
ON 16 BYTE BOUNDARIES +1: PM1_STS2
+2: PM1_EN1
+3: PM1_EN2
+4: PM1_CNTRL1
+5: PM1_CNTRL2
+6: Reserved
+7: Reserved
+8: PM1_TMR1
+9: PM1_TMR2
+10: PM 1_TMR3
+11: PM 1_TMR4
+0: SCI_STS1
[0x0000:0xFFFF]
ON 8 BYTE BOUNDRIES +1: SCI_STS2
+2: SCI_EN1
+3: SCI_EN2
+4: MSC_STS
+5: Reserved
+6: MSC_EN
+7: MSC_CNTRL
This chip uses ISA address bits [A11:A0] to decode the base address of each of its
logical devices.
The IDE/FDC split register, normally found at either 0x3F7 or 0x377 is now an FDC
support only register. The IDE logical device will now support only a status register
(typically found at 0x3F6 or 0x376). The IDE Decoder operates as follows:
nHDCS0# = IDE TASK BASE + [7:0]
nHDCS1# = IDE MISC AT BASE + 0 (typically located at 0x3F6 or 0x376)
204
Table 94 - Interrupt Select Configuration Register Description
REG INDEX
DEFINITION
NAME
Interrupt
Request Level
Select 0
0x70 (R/W)
Default = 0x00
on VCC POR or
Reset_Drv
Bit[3:0] selects which interrupt level is used for Interrupt
0.
0x00=no interrupt selected.
0x01=IRQ1
0x02=Reserved
0x03=IRQ3
•
•
•
0x0D=Reserved/IRQ13 (Note 1)
0x0E=IRQ14
0x0F=IRQ15
All interrupts are edge high (except ECP/EPP)
STATE
C
Note: An Interrupt is activated by setting the Interrupt Request Level Select 0 register to a non-zero
value AND :
for the FDC logical device by setting DMAEN, bit D3 of the Digital Output Register.
for the PP logical device by setting IRQE, bit D4 of the Control Port and in addition
for the PP logical device in ECP mode by clearing serviceIntr, bit D2 of the ecr.
for the Serial Port logical device by setting any combination of bits D0-D3 in the IER and by
setting the OUT2 bit in the UART's Modem Control (MCR) Register.
for the RTC by (refer to the RTC section of this spec.)
for the KYBD by (refer to the KYBD controller section of this spec.)
Note: IRQ pins must tri-state if not used/selected by any Logical Device. Refer to Note A.
Note: IRQ 13 is only valid for SCI, as selected through Logical Device A.
NAME
Table 95 - DMA Channel Select Configuration Register Description
REG INDEX
DEFINITION
DMA Channel
Select
Default = 0x04
on VCC POR or
Reset_Drv
Note 1:
Note 2:
0x74 (R/W)
Bit[2:0] select the DMA Channel.
0x00=DMA0
0x01=DMA1
0x02=DMA2
0x03=DMA3
0x04-0x07= No DMA active
STATE
C
A DMA channel is activated by setting the DMA Channel Select register to [0x00-0x03]
AND :
for the FDC logical device by setting DMAEN, bit D3 of the Digital Output Register.
for the PP logical device in ECP mode by setting dmaEn, bit D3 of the ecr.
DMAREQ pins must tri-state if not used/selected by any Logical Device.
205
Note A: Logical Device IRQ and DMA Operation
1.
IRQ and DMA Enable and Disable: Any time the IRQ or DACK for a logical block is disabled by
a register bit in that logical block, the IRQ and/or DACK must be disabled. This is in addition to
the IRQ and DACK disabled by the Configuration Registers (active bit or address not valid).
a. FDC: For the following cases, the IRQ and DACK used by the FDC are disabled (high
impedance). Will not respond to the DREQ
•
Digital Output Register (Base+2) bit D3 (DMAEN) set to "0".
•
The FDC is in power down (disabled).
b. IDE1 and IDE2: No additional conditions.
c. Serial Port 1 and 2:
•
Modem Control Register (MCR) Bit D2 (OUT2) - When OUT2 is a logic "0", the
serial port interrupt is forced to a high impedance state - disabled.
d. Parallel Port:
•
SPP and EPP modes: Control Port (Base+2) bit D4 (IRQE) set to "0", IRQ
disabled (high impedance).
•
ECP Mode:
(1) (DMA) dmaEn from ecr register. See table.
(2) IRQ - See table.
MODE
(FROM ECR REGISTER)
IRQ PIN
PDREQ PIN
CONTROLLED BY CONTROLLED BY
000
PRINTER
IRQE
dmaEn
001
SPP
IRQE
dmaEn
010
FIFO
(on)
dmaEn
011
ECP
(on)
dmaEn
100
EPP
IRQE
dmaEn
101
RES
IRQE
dmaEn
110
TEST
(on)
dmaEn
111
CONFIG
IRQE
dmaEn
e. Game Port and ADDR: no IRQ or DACK used.
f. Real Time Clock and Keyboard Controller: Refer to the RTC and KBD section of this
spec.
206
is
Configuration Registers reset to their default
values only on hard resets generated by VCC or
VTR POR (as shown) or the RESET_DRV
signal. These registers are not affected by soft
resets.
SMSC Defined Logical Device Configuration
Registers
The
SMSC
Specific
Logical
Device
Table 96 - Floppy Disk Controller, Logical Device 0 [Logical Device Number = 0x00]
NAME
REG INDEX
FDD Mode Register
0xF0 R/W
Bit[0] Floppy Mode
= 0 Normal Floppy Mode (default)
= 1 Enhanced Floppy Mode 2 (OS2)
Bit[1] FDC DMA Mode
=0
Burst Mode is enabled
=1
Non-Burst Mode (default)
Bit[3:2] Interface Mode
= 11 AT Mode (default)
= 10 (Reserved)
= 01 PS/2
= 00 Model 30
Bit[4] Swap Drives 0,1 Mode
=0
No swap (default)
=1
Drive and Motor sel 0 and 1 are swapped.
Bit[7:5] Reserved, set to zero.
C
0xF1 R/W
Bit[1:0] Reserved, set to zero
Bit[3:2] Density Select
= 00 Normal (default)
= 01 Normal (reserved for users)
= 10 1 (forced to logic "1")
= 11 0 (forced to logic "0")
Bit[4] Media ID 0 Polarity
= 0: Don’t invert (default)
= 1: Invert
Bit[5] Media ID 1 Polarity
= 0: Don’t invert (default)
= 1: Invert
Bits[7:6] Boot Floppy
= 00 FDD 0 (default)
= 01 FDD 1
= 10 Reserved (neither drive A or B is a boot
drive).
= 11 Reserved (neither drive A or B is a boot
drive).
C
Default = 0x0E
on VCC POR or
Reset_Drv
FDD Option
Register
Default = 0x00
on VCC POR or
Reset_Drv
DEFINITION
207
STATE
Table 96 - Floppy Disk Controller, Logical Device 0 [Logical Device Number = 0x00]
NAME
REG INDEX
FDD Type Register
0xF2 R/W
Default = 0xFF
on VCC POR or
Reset_Drv
0xF3 R
FDD0
STATE
Bit[1:0] Floppy Drive A Type
Bit[3:2] Floppy Drive B Type
Bit[5:4] Reserved (could be used to store Floppy
Drive C type)
Bit[7:6] Reserved (could be used to store Floppy
Drive D type)
Note: The FDC37C93xAPM supports two floppy
drives
C
Reserved, Read as 0 (read only)
C
0xF4 R/W
Bit[1:0] Drive Type Select: DT1, DT0
Bit[2] Read as 0 (read only)
Bit[4:3] Data Rate Table Select: DRT1, DRT0
Bit[5] Read as 0 (read only)
Bit[6] Precompensation Disable PTS
=0 Use Precompensation
=1 No Precompensation
Bit[7] Read as 0 (read only)
C
0xF5 R/W
Refer to definition and default for 0xF4
C
Default = 0x00
on VCC POR or
Reset_Drv
FDD1
DEFINITION
208
Table 97 - IDE Drive 1, Logical Device 1 [Logical Device Number = 0x01]
NAME
REG INDEX
DEFINITION
HDCS0 Address
Decoder
0xF0 R/W
Bit[7:5] Reserved
Bit[4:2] Mask Bits
4 3 2 Description
0 0 0 mask no bits (1 byte)
0 0 1 mask lowest bit (2 bytes)
0 1 0 mask lowest 2 bits (4 bytes)
0 1 1 mask lowest 3 bits (8 bytes)
1 0 0 mask lowest 4 bits (16 bytes)
1 0 1 mask lowest 5 bits (32 bytes)
1 1 0 reserved (do not program)
1 1 1 reserved ( do not program)
Default = 0x0C
on Vcc POR or
Reset_Drv or
Software Reset
Bit[1:0] Qualify for HDCS0 Option Select
1 0 Description
0 0 = decoded with AEN
0 1 = decoded with AEN and nIOR
1 0 = decoded with AEN and nIOW
1 1 = decoded with AEN and (nIOR or nIOW)
HDCS1 Address
Decoder
Default = 0x00
on Vcc POR or
Reset_Drv or
Software Reset
0xF1 R/W
Bit[7:5] Reserved
Bit[4:2] Mask Bits
4 3 2 Description
0 0 0 mask no bits (1 byte)
0 0 1 mask lowest bit (2 bytes)
0 1 0 mask lowest 2 bits (4 bytes)
0 1 1 mask lowest 3 bits (8 bytes)
1 0 0 mask lowest 4 bits (16 bytes)
1 0 1 mask lowest 5 bits (32 bytes)
1 1 0 reserved (do not program)
1 1 1 reserved ( do not program)
Bit[1:0] Qualify for HDCS1 Option Select
1 0 Description
0 0 = decoded with AEN
0 1 = decoded with AEN and nIOR
1 0 = decoded with AEN and nIOW
1 1 = decoded with AEN and (nIOR or nIOW)
Note: IDE1 HI and LO byte pass through external buffers controlled by IDE1_OE.
209
STATE
Table 98 - IDE Drive 2, Logical Device 2 [Logical Device Number = 0x02]
NAME
IDE2
Mode Register
Default = 0x00
on VCC POR or
Reset_Drv
REG INDEX
DEFINITION
STATE
0xF0 R/W
Bit[0] : IDE2 Configuration Options
= 0 : IDE2 HI and LO bytes pass through external
buffers controlled by IDE2_OE.
= 1 : IDE2_OE not used. IDE2 HI and LO byte
passes through external buffer controlled by
IDE1_OE.
Bit[7:1] : Reserved, set to “0”
C
When IDE2 is not active (IDE2 active bit = L2 - CR30 - bit 0), nHDCS2, nHDCS3 and IDE2_IRQ are in
high impedance; 16_ADR = CR24.6
Table 99 - 16 Bit Address Qualification
IDE2 ACTIVE BIT = 1
IDE2 ACTIVE BIT = 0
16BIT_ADR = X
16BIT_ADR = 0
IDE2 ACTIVE BIT = 0
16BIT_ADR = 1
nHDCS2 (pin 27)
Output
Hi-Z
Input (SA13)
nHDCS3 (pin 28)
Output
Hi-Z
Input (SA14)
IDE2_IRQ (pin 29)
Input (IRQ)
Hi-Z
Input (SA15)
nCS (pin 53)
Input (SA12)
Input (SA12)
Input (SA12)
210
Table 100 - Parallel Port, Logical Device 3 [Logical Device Number = 0x03]
NAME
PP Mode Register
REG INDEX
DEFINITION
STATE
0xF0 R/W
Bit[2:0] Parallel Port Mode
= 100 Printer Mode (default)
= 000 Standard and Bi-Directional (SPP) Mode
= 001 EPP-1.9 and SPP Mode
= 101 EPP-1.7 and SPP Mode
= 010 ECP Mode
= 011 ECP and EPP-1.9 Mode
= 111 ECP and EPP-1.7 Mode
Bit[6:3] ECP FIFO Threshold
0111b (default)
Bit[7] PP Interupt Type
Not valid when the parallel port is in the Printer
Mode (100) or the Standard & Bi-directional Mode
(000).
= 1 Pulsed Low, released to high-Z.
= 0 IRQ follows nACK when parallel port in EPP
Mode or [Printer,SPP, EPP] under ECP.
IRQ level type when the parallel port is in ECP,
TEST, or Centronics FIFO Mode.
C
0xF1 R/W
Bit[1:0] PPFDC - muxed PP/FDC control
= 00 Normal Parallel Port Mode
= 01 PPFD1: Drive 0 is on the FDC pins
Drive 1 is on the parallel port pins
Drive 2 is on the FDC pins
Drive 3 is on the FDC pins
= 10 PPFD2: Drive 0 is on the parallel port pins
Drive 1 is on the Parallel port pins
Drive 2 is on the FDC pins
Drive 3 is on the FDC pins
Bit[7:2] Reserved. Set to “0”
Default = 0x3C
on VCC POR or
Reset_Drv
PP Mode Register 2
Default = 0x00
on VCC POR or
Reset_Drv
211
Table 101 - Serial Port 1, Logical Device 4 [Logical Device Number = 0x04]
NAME
Serial Port 1
Mode Register
REG INDEX
0xF0 R/W
Default = 0x00
on VCC POR or
Reset_Drv
DEFINITION
STATE
Bit[0] MIDI Mode
= 0 MIDI support disabled (default)
= 1 MIDI support enabled
Bit[1] High Speed
= 0 High Speed Disabled(default)
= 1 High Speed Enabled
Bit[6:2] Reserved, set to zero
Bit[7]: Share IRQ
=0 UARTS use different IRQs
=1 UARTS share a common IRQ
See Note below
Note: To properly share an IRQ:
1. Configure UART1 (or UART2) to use the desired IRQ pin.
2. Configure UART2 (or UART1) to use No IRQ selected.
3. Set the share IRQ bit.
If both UARTs are configured to use different IRQ pins and the share IRQ bit is set,
UART IRQ pins will assert when either UART generates an interrupt.
C
then both of the
Table 102 - Serial Port 2, Logical Device 5 [Logical Device Number = 0x05]
NAME
Serial Port 2
Mode Register
Default = 0x00
on VCC POR or
Reset_Drv
REG INDEX
0xF0 R/W
DEFINITION
Bit[0] MIDI Mode
= 0 MIDI support disabled (default)
= 1 MIDI support enabled
Bit[1] High Speed
= 0 High Speed disabled(default)
= 1 High Speed enabled
Bit[7:2] Reserved, set to “0”
212
STATE
C
Table 102 - Serial Port 2, Logical Device 5 [Logical Device Number = 0x05]
NAME
IR Option Register
REG INDEX
0xF1 R/W
Default = 0x02
on VCC POR or
Reset_Drv
IR Half Duplex
Timeout
Default = 0x03
on VCC POR or
Reset_Drv
0xF2
DEFINITION
Bit[0] Receive Polarity
=0
Active High (Default)
=1
Active Low
Bit[1] Transmit Polarity
= 0 Active High
= 1 Active Low (Default)
Bit[2] Duplex Select
=0
Full Duplex (Default)
= 1 Half Duplex
Bit[5:3] IR Mode
= 000 Standard (Default)
= 001 IrDA
= 010 ASK-IR
= 011 Reserved
= 1xx Reserved
Bit[6] IR Location Mux
=0
Use Serial port TX2 and RX2 (Default)
=1
Use alternate IRRX (pin 98) and IRTX (pin
99)
Bit[7] Reserved, write 0.
Bit [7:0]
These bits set the half duplex time-out for the IR port.
This value is 0 to 10msec in 100µsec increments.
0= blank during transmit/receive
1= blank during transmit/receive + 100µsec
213
STATE
C
Table 103 - RTC, Logical Device 6 [Logical Device Number = 0x06]
NAME
REG INDEX
DEFINITION
STATE
RTC Mode Register
0xF0 R/W
Bit[0] = 1 Lock CMOS RAM 80-9Fh
Bit[1] = 1 Lock CMOS RAM A0-BFh
Bit[2] = 1 Lock CMOS RAM C0-DFh
Bit[3] = 1 Lock CMOS RAM E0-FFh
Bit[6:4] Bank Selection if Bit[7]=1 (Note 1)
=000 Bank 1 at Secondary Base Address (Default)
(Note 2)
=001 Bank 0 at 70h and Bank 1 at Secondary Base
Address (Note 3)
=010 Reserved (Note 2)
=011 Bank 0 at 70h
=100 Reserved (Note 2)
=101 Bank 0 at 70h
=110 Bank 2 at Secondary Base Address (Note 2)
=111 Bank 0 at 70h and Bank 2 at Secondary Base
Address (Note 3)
Bit[7] Bank Selection (Note 1)
= 0 Select Bank 0 at 70h
= 1 Select Bank(s) based on Bits[6:4]
Once set, bit[3:0] cannot be cleared by a write;
bit[3:0] are cleared only on VCC Power On Reset or
upon a Hard Reset.
C
0xF1 R/W
Bit[0] = 1 : Lock EEPROM 00-1Fh
Bit[1] = 1 : Lock EEPROM 20-3Fh
Bit[2] = 1 : Lock EEPROM 40-5Fh
Bit[3] = 1 : Lock EEPROM 60-7Fh
Bit[4] EEPROM Type
= 0 256 bit,1 Kbps (93C06,93C46)
= 1 2 Kbps, 4 Kbps (93C56,93C66)
Bit[7:5] Reserved, set to zero
Once set, bit[3:0] can not be cleared by a write;
bit[3:0] are cleared only on VCC Power On Reset or
upon a Hard Reset.
C
0xF2 R/W
Use this register to set the Serial EEPROM's pointer.
The value in this register always reflects the current
EEPROM pointer address. The Serial Device Pointer
increments after each pair of reads from the
Resource Data register or after each pair of writes to
the Program Resource Data register.
C
Default = 0x00
on VCC POR or
Reset_Drv
Serial EEPROM
Mode Register
Default = 0x00
on VCC POR or
Reset_Drv
Serial EEPROM
Pointer
Default = 0x00, on
VCC POR,Reset_Drv
or Software Reset.
214
Table 103 - RTC, Logical Device 6 [Logical Device Number = 0x06]
NAME
Write EEPROM
Data
Write Status
Default = 0x03, on
VCC POR,
Reset_Drv
or Software Reset
REG INDEX
DEFINITION
STATE
0xF3 W
This register is used to program the serial device
from the host.
This device supports serial
EEPROMS in x16 configurations. Two bytes must
be written to this register in order to generate an
EEPROM write cycle. The LSB leads the MSB. The
first write to this register resets bit 0 of the Write
Status register. The second write resets bit 1 of the
Write Status register and generates a write cycle to
the serial EEPROM. The Write Status register must
be polled before performing a pair of writes to this
register.
C
0xF4
Bit [1:0]
= 1,1 Indicates that the Write EEPROM Data
register is ready to accept a pair of bytes.
= 1,0 Bit 0 is cleared on the first write of the Write
EEPROM Data register.
This status
indicates that the serial device controller has
received one byte (LSB) and is waiting for
the second byte (MSB).
= 0,0 Bit 1 is cleared on the second write of the
Write EEPROM Data register indicating that
two bytes have been accepted and that the
serial device interface is busy writing the
word to the EEPROM.
Bit [6:2] Reserved, set to “0”
Bit [7]
= 0 Enables a prefetch of serial EEPROM when
the Serial EEPROM Pointer Register is
written. This will typically be used when the
host CPU wishes random read access from
the serial EEPROM.
= 1 Disables a prefetch of serial EEPROM when
the Serial EEPROM Pointer Register is
written. This bit is typically set when the
host CPU wishes to perform random word
or block writes to the serial EEPROM.
C
Bit[6:0]
Read Only
Bit[7] R/W
215
Table 103 - RTC, Logical Device 6 [Logical Device Number = 0x06]
NAME
REG INDEX
DEFINITION
STATE
Read EEPROM
Data
0xF5 R
This register allows the host to read data from the
serial EEPROM. Data is not valid in this register
until bit 0 of the Read Status Register is set. Since
the EEPROM is a 16-bit device, this register presents
the LSB followed by the MSB for each pair of register
reads. Immediately after the MSB is read, bit 0 of
the Read Status Register will be cleared, then the
Serial EEPROM Pointer Register will be autoincremented, then the next word of EEPROM data
will be fetched, followed by the Read Status Register,
bit 0 being set.
C
Read Status
0xF6 R
Bit 0 = 1 indicates that data in the Read EEPROM
Data register is valid. This bit is cleared when
EEPROM Data is read until the next byte is valid.
Reading the Read EEPROM Data register when bit-0
is clear will have no detremental effects; the data will
simply be invalid.
C
Note 1:
The RTC modifications allow for backwards compatibility. If Bit[7] of the RTC Mode
Register is set to 0, Bank 0 is selected at 70h. If Bit[7] is set to 1, the default values for Bit[6:4] and
the Secondary Base Address for RTC Bank 1 and 2 (CR62 and CR63) are such that Bank 1 is
selected at 70h.
For added capability, Banks 1 and 2 can be selected and relocated to another address. Bank 1 can be
selected either individually or with Bank 0 by setting Bit[7] of the RTC Mode Register and setting
Bit[6:4] appropriately. For example, with Bit[7] = 1, setting Bit[6:4] to 000 selects Bank 1; setting
Bit[6:4] to 001 selects Bank 0 and Bank 1. Similarly, Bank 2 can be selected either individually or with
Bank 0. For example, with Bit[7] = 1, setting Bit[6:4] to 110 selects Bank 2; setting Bit[6:4] to 111
selects Bank 0 and Bank 2.
These banks are relocatable through Configuration Registers 62 and 63 in Logical Device 6, the
Secondary Base Address for RTC Bank 1 and Bank 2. This 16-bit address register only applies to
Banks 1 and 2 and will only be used for address decode if Bit[7] in the RTC Mode Register is set to 1.
As an example, setting CR62 to 04 and CR63 to 70 moves Banks 1 and 2 to address 470h. Bank 0 is
always located at 70h.
The Secondary Base Address must be at an even address. The Data Register is at the Secondary
Base Address + 1.
Note 2:
Bank 0 is “off”
Note 3:
The secondary base address must be set to a value other than 70h prior to selecting this
option.
216
Table 104 - KEYBOARD, Logical Device 7 [Logical Device Number = 0x07]
NAME
REG INDEX
DEFINITION
KRST_GA20
0xF0
KRESET and GateA20 Select
R/W
Bit[7] Polarity Select for P12
= 0 P12 active low (default)
= 1 P12 active high
Bit[6:3] Reserved
Bit[2] Port 92 Select
= 0 Port 92 Disabled
= 1 Port 92 Enabled
Bit[1] GATEA20 Select
= 0 Software Control
= 1 Hardware Speed-up
Bit[0] KRESET Select
= 0 Software Control
= 1 Hardware Speed-up
Default = 0x00
on VCC POR or
Reset_Drv
0xF1 -
Reserved - read as “0”
0xFF
217
STATE
Table 105 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG
DEFINITION
INDEX
0xB0 R/W
The following bits are the enables for the wake-up
Soft Power Enable
function of the nPowerOn bit. When enabled, these
Register 1
bits allow their corresponding function to turn on
power to the system.
Default = 0x00
on VTR POR
1 = ENABLED
0 = DISABLED
Bit[0] SP_RI1: UART 1 Ring Indicator Pin
Bit[1] SP_RI2: UART 2 Ring Indicator Pin
Bit[2] SP_KCLK: Keyboard Clock pin
Bit[3] SP_MCLK: Mouse Clock pin
Bit[4] SP_GPINT1: Group Interrupt 1
Bit[5] SP_GPINT2: Group Interrupt 2
Bit[6] SP_IRRX2: IRRX2 input pin
Bit[7] SP_RTC ALARM: RTC Alarm
Soft Power Enable
0xB1 R/W
The following bits are the enables for the wake-up
Register 2
function of the nPowerOn bit. When enabled, these
bits allow their corresponding function to turn on
power to the system.
Default = 0x80
on VTR POR
1 = ENABLED
0 = DISABLED
Bit[0] SP_RXD1: UART 1 Receive Data Pin
Bit[1] SP_RXD2: UART 2 Receive Data Pin
Bit[3:2] Reserved
Bit[4] AL2_EN: Alarm 2 Enable. Defaults to 0.
Bit[5] Reserved
Bit[6] PG_EN: Power Good Enable. Defaults to 0.
=0 Disabled (nPowerOn pin not used for power
good)
=1 Enabled (nPowerOn pin used as power good)
Bit[7] OFF_EN: After power up, this bit defaults to 1,
i.e., enabled. This bit allows the software to
enable or disable the button control of power
off.
218
STATE
C
C
Table 105 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG
DEFINITION
INDEX
0xB2 R/W
The following bits are the status for the wake-up
Soft Power Status
function of the nPowerOn bit. These indicate which of
Register 1
the enabled wakeup functions caused the power up.
Default = 0x00
1 = Occured
on VTR POR
0 = Did not occur since last cleared
The following signals are latched to detect and hold
the soft power event (Type 1)
Bit[0] RI1: UART 1 Ring Indicator; high to low
transition on the pin, cleared by a read of this
register
Bit[1] RI2: UART 2 Ring Indicator; high to low
transition on the pin, cleared by a read of this
register
Bit[2] KCLK: Keyboard clock; high to low transition
on the pin, cleared by a read of this register
Bit[3] MCLK: Mouse clock; high to low transition on
the pin, cleared by a read of this register
Bit[6] IRRX2: IRRX2 input; high to low transition on
the pin, cleared by a read of this register
Bit[7] RTC ALARM: RTC Alarm; status of the RTC
Alarm internal signal. Cleared by a read of the
status register.
The following signals are not latched to detect and
hold the soft power event (Type 2)
Bit[4] GPINT1: Group Interrupt 1; status of the
GPINT1 internal signal. Cleared at the source.
Bit[5] GPINT2: Group Interrupt 2; status of the
GPINT2 internal signal. Cleared at the source.
219
STATE
C
Table 105 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG
DEFINITION
INDEX
0xB3 R/W
The following bits are the status for the wake-up
Soft Power Status
function of the nPowerOn bit. These indicate which
Register 2
of the enabled wakeup functions caused the power
up.
Default = 0x00
on VTR POR
1 = Occured
0 = Did not occur since last cleared
STATE
C
The following signals are latched to detect and hold
the soft power event (Type 1)
Bit[0] RXD1: UART 1 Receive Data; high to low
transition on the pin, cleared by a read of this
register
Bit[1] RXD2: UART 2 Receive Data; high to low
transition on the pin, cleared by a read of this
register
Bit[4] AL2: RTC Alarm 2 status; Cleared by a read
of this register.
Bit[5] Reserved
SMI Enable
Register 1
Default = 0x00
on VTR POR
0xB4 R/W
The following signal is latched to detect and hold the
soft power event (Type 3) but the output of the latch
does not feed into the power down circuitry:
Bit[2] Button: Button pressed, Cleared by a read of
this register
Bit[3] Reserved
Bits[7:6] Reserved
This register is used to enable the different interrupt
sources onto the group nSMI output.
1=Enable
0=Disable
Bit[0] EN_IDE1
Bit[1] EN_PINT
Bit[2] EN_U2INT
Bit[3] EN_U1INT
Bit[4] EN_FINT
Bit[5] EN_GPINT2
Bit[6] EN_GPINT1
Bit[7] EN_WDT
220
C
Table 105 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG
DEFINITION
INDEX
0xB5 R/W
This register is used to enable the different interrupt
SMI Enable
sources onto the group nSMI output, and the group
Register 2
nSMI output onto the nSMI GPI/O pin.
Default = 0x00
Unless otherwise noted,
on VTR POR
1=Enable
0=Disable
SMI Status
Register 1
Default = 0x00
on VTR POR
0xB6 R/W
Bit[0] EN_MINT
Bit[1] EN_KINT
Bit[2] EN_IRINT
Bit[3] EN_BINT
Bit[4] EN_P12: Enable 8042 P1.2 to route internally
to nSMI. 0=Do not route to nSMI, 1=Enable
routing to nSMI.
Bit[5] EN_ABINT: Access bus interrupt.
Bit[6] RTC_EN: This bit is used to enable the
setting of the RTC_STS bit to generate an SMI. The
RTC_STS bit is set anytime the RTC generates an
alarm 2.
Bit[7] EN_SMI: Enable the group nSMI output onto
the nSMI GPI/O pin. 0=SMI pin floats, 1=Enable
group nSMI output onto nSMI GPI/O pin.
This register is used to read the status of the SMI
inputs.
The following bits must be cleared at their source.
Bit[0] IDE1 (IDEInterrupt)
Bit[1] PINT (Parallel Port Interrupt)
Bit[2] U2INT (UART 2 Interrupt)
Bit[3] U1INT (UART 1 Interrupt)
Bit[4] FINT (Floppy Disk Controller Interrupt)
Bit[5] GPINT2 (Group Interrupt 2)
Bit[6] GPINT1 (Group Interrupt 1)
Bit[7] WDT (Watch Dog Timer)
221
STATE
C
C
Table 105 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG
DEFINITION
INDEX
0xB7 R/W
This register is used to read the status of the SMI
SMI Status
inputs.
Register 2
Bit[0] MINT: Mouse Interrupt. Cleared at source.
Bit[1] KINT: Keyboard Interrupt. Cleared at source.
Default = 0x00
Bit[2] IRINT: This bit is set by a transition on the IR
on VTR POR
pin (RDX2 or GP12 as selected in CR L5-F1-B6 i.e.,
after the MUX). Cleared by a read of this register.
Bit[3] BINT: This bit is set when the DELAY counter
is started. Cleared by a read of this register.
Bit[4] P12: 8042 P1.2. Cleared at source
Bit[5] ABINT: Access Bus Interrupt. Cleared at
source.
Bit[6] RTC_STS: This bit is set when the RTC
generates an alarm 2. Additionally if the RTC_EN bit
is set then the setting of the RTC_STS bit will
generate an SMI. Cleared by writing a 1 to this
location. Writing a 0 has no effect.
Bit[7] Reserved
Delay 2 Time Set
0xB8 R/W
This register is used to set Delay 2 (for Soft Power
Register
Management) to a value from 500 msec to 32 sec.
The default value is 500msec.
Default = 0x00
on VTR POR
Bit[5:0] The value of these bits correspond to the
delay time as follows:
000000= 500msec min to 510msec max
000001= 1sec min to 1.01sec max
000010= 1.5sec min to 1.51sec max
000011= 2sec min to 2.01sec max
...
111111 = 32sec min to 32.01sec max
Bit[7:6] Reserved
222
STATE
C
C
Table 105 (cont’d) - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
C
GP40
0xC0
General Purpose I/O bit 4.0
Bit[4:3] Function Select
=00 MEDIA_ID1
Default= 0x01
=01 GPI/O
on VTR POR
=10 IR Mode
=11 IRR3
C
GP41
0xC1
General Purpose I/O bit 4.1
Bit[4:3] Function Select
=00 MEDIA_ID0
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
C
GP42
0xC2
General Purpose I/O bit 4.2
Bit[4:3] Function Select
=00 nIDE1_OE
Default= 0x00
=01 GPI/O
on VTR POR
=10 Either Edge Triggered Interrupt Input 1
Enable
=11 Reserved
GP43
0xC3
General Purpose I/O bit 4.3
C
Bit[4:3] Function Select
Default= 0x00
=00 nHDCS0
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP44
0xC4
General Purpose I/O bit 4.4
C
Bit[4:3] Function Select
Default= 0x00
=00 nHDCS1
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP45
0xC5
General Purpose I/O bit 4.5
C
Bit[4:3] Function Select
Default= 0x01
=00 IDE1_IRQ
on VTR POR
=01 GPI
=10 Reserved
=11 Reserved
223
Table 105 (cont’d) - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
C
GP46
0xC6
General Purpose I/O bit 4.6
Bit[4:3] Function Select
=00 nIOROP
Default= 0x01
=01 GPI/O
on VTR POR
=10 Power LED Output
=11 WDT
C
GP47
0xC7
General Purpose I/O bit 4.7
Bit[4:3] Function Select
=00 nIOWOP
Default= 0x01
=01 GPI/O
on VTR POR
=10 nSMI
=11 Reserved
C
GP50
0xC8
General Purpose I/O bit 5.0
Bit[4:3] Function Select
=00 Button_In
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
GP51
0xC9
General Purpose I/O bit 5.1
C
Bit[4:3] Function Select
Default= 0x80
=00 nPowerOn
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP53
0xCB
General Purpose I/O bit 5.3
C
Bit[4:3] Function Select
Default= 0x01
=00 nROMCS
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP54
0xCC
General Purpose I/O bit 5.4
C
Bit[4:3] Function Select
Default= 0x01
=00 nROMOE
on VTR POR
=01 GPI/O
=10 IR Mode
=11 IRR3
0xCD-0xCF
Reserved
C
GP60
0xD0
General Purpose I/O bit 6.0
C
Bit[4:3] Function Select
Default= 0x01
=00 RD0
on VTR POR
=01 GPI/O
=10 Power Led Output
=11 Reserved
224
Table 105 (cont’d) - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
C
GP61
0xD1
General Purpose I/O bit 6.1
Bit[4:3] Function Select
=00 RD1
Default= 0x01
=01 GPI/O
on VTR POR
=10 WDT
=11 Reserved
C
GP62
0xD2
General Purpose I/O bit 6.2
Bit[4:3] Function Select
=00 RD2
Default= 0x01
=01 GPI/O
on VTR POR
=10 8042 - P12
=11 Reserved
C
GP63
0xD3
General Purpose I/O bit 6.3
Bit[4:3] Function Select
=00 RD3
Default= 0x01
=01 GPI/O
on VTR POR
=10 8042 - P13
=11 Reserved
GP64
0xD4
General Purpose I/O bit 6.4
C
Bit[4:3] Function Select
Default= 0x01
=00 RD4
on VTR POR
=01 GPI/O
=10 8042 - P14
=11 Reserved
GP65
0xD5
General Purpose I/O bit 6.5
C
Bit[4:3] Function Select
Default= 0x01
=00 RD5
on VTR POR
=01 GPI/O
=10 8042 - P15
=11 Reserved
GP66
0xD6
General Purpose I/O bit 6.6
C
Bit[4:3] Function Select
Default= 0x01
=00 RD6
on VTR POR
=01 GPI/O
=10 8042 - P16
=11 Reserved
GP67
0xD7
General Purpose I/O bit 6.7
C
Bit[4:3] Function Select
Default= 0x01
=00 RD7
on VTR POR
=01 GPI/O
=10 8042 - P17
=11 Reserved
225
Table 105 (cont’d) - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
C
GP70
0xD8
General Purpose I/O bit 7.0
Bit[4:3] Function Select
=00 nRI2
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
C
GP71
0xD9
General Purpose I/O bit 7.1
Bit[4:3] Function Select
=00 nDCD2
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
C
GP72
0xDA
General Purpose I/O bit 7.2
Bit[4:3] Function Select
=00 RXD2
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
GP73
0xDB
General Purpose I/O bit 7.3
C
Bit[4:3] Function Select
Default= 0x01
=00 TXD2
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP74
0xDC
General Purpose I/O bit 7.4
C
Bit[4:3] Function Select
Default= 0x01
=00 nDSR2
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP75
0xDD
General Purpose I/O bit 7.5
C
Bit[4:3] Function Select
Default= 0x01
=00 nRTS2
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
GP76
0xDE
General Purpose I/O bit 7.6
C
Bit[4:3] Function Select
Default= 0x01
=00 nCTS2
on VTR POR
=01 GPI/O
=10 Reserved
=11 Reserved
226
Table 105 (cont’d) - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
C
GP77
0xDF
General Purpose I/O bit 7.7
Bit[4:3] Function Select
=00 nDTR2
Default= 0x01
=01 GPI/O
on VTR POR
=10 Reserved
=11 Reserved
227
Definition for GP Registers
Bit[0] In/Out: =1 Input, =0 Output
Bit[1] Polarity: =1 Invert, =0 No Invert
Bit[2] Int En 1:
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[4:3] Function Select
=00 Original Function
=01 Alternate Function 1
=10 Alternate Function 2 (or Reserved)
=11 Alternate Function 3 (or Reserved)
Bit[5] Reserved
Bit[6] Int En 2
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[7] Open Collector: =1 Open Collector, =0 Push Pull
Therefore, unless otherwise required, only Bit[4:3] are defined in the following table.
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP10
Default = 0x01
on VTR POR
REG INDEX
DEFINITION
STATE
0xE0
General Purpose I/0 bit 1.0
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func
(If configured as input, the input signal is steered to
the selected IRQ)
=1 Select alternate function
=0 Select basic I/O function
Bit[7:4] Alt Fuct IRQ mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
C
228
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP11
REG INDEX
DEFINITION
STATE
0xE1
General Purpose I/0 bit 1.1
Bit[0] In/Out: =1 input, =0 Output
Bit[1] Polarity: =1 invert, =0 No invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3-7] These bits are used for selection of the pin
function as follows:
Bit
7 6 5 4 3 Function Output Type IRQ Mapping
0 x x 0 0 GPIO
Push Pull
N/A
1 x x 0 0 GPIO
Open Collector N/A
0 x x 1 0 IRQ13
Push Pull
N/A
1 x x 1 0 IRQ13 Open Collector
N/A
1 1 1 1 1 IRQIN
Push Pull
IRQ15
1 1 1 0 1 IRQIN
Push Pull
IRQ14
1 1 0 1 1 IRQIN
Push Pull
Reserved
.....
0 0 1 1 1 IRQIN
Push Pull
IRQ3
0 0 1 0 1 IRQIN
Push Pull
Reserved
0 0 0 1 1 IRQIN
Push Pull
IRQ1
0 0 0 0 1 IRQIN
Push Pull
Disable
General Purpose I/0 bit 1.2
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func WDT output or IRRX input.
=1 Select alternate function
=0 Select basic I/O function
(IRRX - if bit-6 of the IR Options Register is set)
Bit[7:4] Reserved = 0000
C
Default = 0x01
on VTR POR
GP12
Default = 0x01
on VTR POR
0xE2
229
C
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP13
REG INDEX
General Purpose I/0 bit 1.3
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func Power LED or IRTX output
=1 Select alternate function
=0 Select basic I/O function
(IRTX - if bit-6 of the IR Options Register is set)
Bit[7:4] Reserved = 0000
C
0xE4
General Purpose I/0 bit 1.4
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func: General Purpose Address Decode
(Active Low) Decodes two address bytes
=1 Select alternate function
=0 Select basic I/O function
Bit[7:4] Reserved = 0000
C
0xE5
General Purpose I/0 bit 1.5
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func: Gen. Purpose Write Strobe (Active
Low)
=1 Select alternate function
=0 Select basic I/O function
Bit[7:4] Reserved = 0000
C
Default = 0x01
on VTR POR
GP15
Default = 0x01
on VTR POR
STATE
0xE3
Default = 0x01
on VTR POR
GP14
DEFINITION
230
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP16
REG INDEX
General Purpose I/0 bit 1.6
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[4:3] Alt Func: Joystick (Active Low)
=01 Joystick RD Strobe function
=10 Joystick CS function
=00 Select basic I/O function
Bit[7:5] Reserved = 000
C
0xE7
General Purpose I/0 bit 1.7
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Function: Joystick Write Strobe (Active
Low)
=1 Select alternate function
=0 Select basic I/O function
Bit[7:4] Reserved = 0000
C
0xE8
General Purpose I/0 bit 2.0
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En =1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func: IDE2 buffer enable (Active Low)
=1 Select alternate function
=0 Select basic I/O function
Bit[4] Alt function: 8042 P20, Typically used to
generate a "Keyboard Reset" used by systems in
order to switch from "protected mode" back to "real
mode"
=1 Select alternate function
=0 Select basic I/O function
Bit[7:5] Reserved = 000
Note: Bit[3] and Bit[4] should not both be set at the
same time
C
Default = 0x01
on VTR POR
GP20
Default = 0x01
on VTR POR
STATE
0xE6
Default = 0x01
on VTR POR
GP17
DEFINITION
231
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP21
REG INDEX
0xE9
Default = 0x01
on VTR POR
GP22
0xEA
Default = 0x01
on VTR POR
GP23
Default = 0x01
on VTR POR
0xEB
DEFINITION
General Purpose I/0 bit 2.1
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[4:3] Alt Func:
=00 Select basic I/O function
=01 Serial EEPROM Data In
=10 AB_DATA
Bit[6:5] Reserved = 0000
Bit[7] Open Collector:
=1 Open Collector,
=0 Push Pull
General Purpose I/0 bit 2.2
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[4:3] Alt Func:
=01 Serial EEPROM Data Out
=00 Select basic I/O function
=10 AB_CLK
Bit[6:5] Reserved = 0000
Bit[7] Open Collector:
=1 Open Collector,
=0 Push Pull
General Purpose I/0 bit 2.3
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[4:3] Function Select
=00 GPIO
=01 Serial EEPROM Clock
=10 Either Edge Triggered Interrupt Input 2 Enable
=11 Reserved
Bit[7:5] Reserved = 0000
232
STATE
C
C
C
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP24
REG INDEX
General Purpose I/0 bit 2.4
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En
=1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[4:3] Function Select
=00 GPIO
=01 Serial EEPROM Enable
=10 Either Edge Triggered Interrupt Input 3 Enable
=11 Reserved
Bit[7:5] Reserved = 000
C
0xED
General Purpose I/0 bit 2.5
Bit[0] In/Out =1 Input, =0 Output
Bit[1] Polarity =1 Invert, =0 No Invert
Bit[2] Int En =1 Enable Combined IRQ
=0 Disable Combined IRQ
Bit[3] Alt Func: GATEA20
=1 Select alternate function
=0 Select basic I/O function
Bit[7:4] : Reserved = 0000
C
0xEE
Reserved
C
0xEF
General Purpose I/O Combined Interrupt 2
Bit[2:0] Reserved, = 000
Bit[3] GP IRQ Filter Select
0=
Debounce Filter Bypassed
1=
Debounce Filter Enabled
Bit[7:4] Combined IRQ mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
Default = 0x01
on VTR POR
GP_INT2
Default = 0x00
on VTR POR
STATE
0xEC
Default = 0x01
on VTR POR
GP25
DEFINITION
233
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
GP_INT1
REG INDEX
STATE
0xF0
General Purpose I/O Combined Interrupt 1
Bit[2:0] Reserved, = 000
Bit[3] GP IRQ Filter Select
0=
Debounce Filter Bypassed
1=
Debounce Filter Enabled
Bit[7:4] Combined IRQ mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
C
0xF1
General Purpose Read/Write Enable
Bit[0] =1 enable GP Address Decoder
=0 disable GPA Address Decoder.
Bit[1] =1 enable GPW, =0 disable GPW
Bit[6:2] Reserved, = 00000
Bit[7] WDT Time-out Value Units Select
= 0 Minutes (default)
= 1 Seconds
C
Default = 0x00
on VTR POR
GPA_GPW_EN
DEFINITION
Default = 0x00
on VCC POR or
Reset_Drv
Note: If the logical device's activate bit is not set then
bits 0 and 1 have no effect.
WDT_VAL
Default = 0x00
on VCC POR or
Reset_Drv
0xF2
Watch-dog Timer Timeout Value
Binary coded, units = minutes (default) or seconds,
selectable via Bit[7] of Reg 0xF1, Logical Device 8.
0x00 Timeout disabled
0x01 Timeout = 1 minute (second)
.........
0xFF Timeout = 255 minutes (seconds)
234
C
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
WDT_CFG
REG INDEX
DEFINITION
STATE
0xF3
Watchdog Timer Configuration
Bit[0] Joy-stick Enable
=1 WDT is reset upon an I/O read or write of the
Game Port
=0 WDT is not affected by I/O reads or writes to the
Game Port.
Bit[1] Keyboard Enable
=1 WDT is reset upon a keyboard interrupt.
=0 WDT is not affected by keyboard interrupts.
Bit[2] Mouse Enable
=1 WDT is reset upon a mouse interrupt
=0 WDT is not affected by mouse interrupts.
Bit[3] PWRLED Timeout enable
=1 Enables the Power LED to toggle at a 1Hz rate
with 50 percent duty cycle while the Watchdog Status bit is set.
=0 Disables the Power LED toggle during Watch-dog
timeout status.
Bit[7:4] WDT Interrupt Mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
C
0xF4
Watchdog Timer Control
Bit[0] Watch-dog Status Bit, R/W
=1 WD timeout occured
=0 WD timer counting
Bit[1] Power LED Toggle Enable, R/W
=1 Toggle Power LED at 1Hz rate with 50 percent
duty cycle. (1/2 sec. on, 1/2 sec. off)
=0 Disable Power LED Toggle
Bit[2] Force Timeout, W
=1 Forces WD timeout event; this bit is self-clearing
Bit[3] P20 Force Timeout Enable, R/W
= 1 Allows rising edge of P20, from the keyboard
controller, to force the WD timeout event. A
WD timeout event may still be forced by
setting the Force Timeout Bit, bit 2.
= 0 P20 activity does not generate the WD timeout
event.
C
Default = 0x00
on Vcc POR or
Reset_Drv
WDT_CTRL
Default = 0x00
Cleared by VTR
POR
235
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
The P20 signal will remain high for a minimum of
1us and can remain high indefinitely. Therefore,
when P20 forced timeouts are enabled, a selfclearing edge-detect circuit is used to generate a
signal which is ORed with the signal generated by
the Force Timeout Bit.
Bit[4] Reserved. Set to 0
Bit[5] Stop_Cnt: This is used to terminate Delay 2
(Note 1) without generating a power own.
This is used if the software determines that
the power down should be aborted. When
read, this bit indicates the following:
Stop_Cnt = 0; Counter running Stop_Cnt =
1; Counter Stopped. Note: The write is self
clearing.
Bit[6] Restart_Cnt: This is used to restart Delay 2
(Note 1) from the button input to the
generation of the power down.
When
restarted, the count will start over and delay
the power down for the time that Delay 2 is
set for (Default=500msec). The software
can continue to do this indefinately with out
allowing a powerdown. This bit is self
clearing. 1=Restart; Automatically cleared.
Bit[7] SPOFF: This is used to force a software power
down. This bit is self clearing.
Note 1: This delay is programmable via the Delay 2
Time Set Register at Logical Device 8, 0xB8.
GP1
Default = 0x00
on VCC POR or
Reset_Drv
GP2
Default = 0x00
on VCC POR or
Reset_Drv
GP4
Default = 0x00
on VCC POR or
Reset_Drv
0xF6
Refer to Table 49 for Bit Definitions.
0xF7
Refer to Table 49 for Bit Definitions.
0xF8
Refer to Table 49 for Bit Definitions.
236
STATE
Table 106 - Auxilliary I/O, Logical Device 8 [Logical Device Number = 0x08]
NAME
REG INDEX
DEFINITION
STATE
0xF9
Refer to Table 49 for Bit Definitions.
GP5
Default = 0x00
on VCC POR or
Reset_Drv
0xFA
Refer to Table 49 for Bit Definitions.
GP6
Default = 0x00
on VCC POR or
Reset_Drv
0xFB
Refer to Table 49 for Bit Definitions.
GP7
Default = 0x00
on VCC POR or
Reset_Drv
Note: Registers GP1-2, WDT_CTRL, GP4-7, Soft Power and SMI Enable and Status Registers are
also available at index 01-0F when not in configuration mode. See Table 49.
Table 107 - Access Bus, Logical Device 9 [Logical Device Number = 0x09]
NAME
REG INDEX
0xF0 0xFF
DEFINITION
Reserved - read as “0”
Table 108 - ACPI, Logical Device A [Logical Device Number=0x0A]
NAME
REG INDEX
DEFINITION
0xF0 0xFF
STATE
Reserved - read as “0”
237
STATE
OPERATIONAL DESCRIPTION
MAXIMUM GUARANTEED RATINGS*
Operating Temperature Range......................................................................................... 0oC to +70oC
Storage Temperature Range..........................................................................................-55o to +150oC
Lead Temperature Range (soldering, 10 seconds) .................................................................... +325oC
Positive Voltage on any pin, with respect to Ground ................................................................Vcc+0.3V
Negative Voltage on any pin, with respect to Ground.................................................................... -0.3V
Maximum Vcc ................................................................................................................................. +7V
*Stresses above those listed above could cause permanent damage to the device. This is a stress
rating only and functional operation of the device at any other condition above those indicated in the
operation sections of this specification is not implied.
Note: When powering this device from laboratory or system power supplies, it is important that the
Absolute Maximum Ratings not be exceeded or device failure can result. Some power supplies exhibit
voltage spikes on their outputs when the AC power is switched on or off. In addition, voltage
transients on the AC power line may appear on the DC output. If this possibility exists, it is suggested
that a clamp circuit be used.
DC ELECTRICAL CHARACTERISTICS (TA = 0°C - 70°C, Vcc = +5 V ± 10%)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
COMMENTS
I Type Input Buffer
Low Input Level
VILI
High Input Level
VIHI
0.8
2.0
V
TTL Levels
V
IS Type Input Buffer
Low Input Level
VILIS
High Input Level
VIHIS
Schmitt Trigger Hysteresis
VHYS
0.8
2.2
250
V
Schmitt Trigger
V
Schmitt Trigger
mV
ICLK Input Buffer
Low Input Level
VILCK
High Input Level
VIHCK
0.4
2.2
V
V
ICLK2 Input Buffer
500
Input Level
238
mV
VP-P
PARAMETER
SYMBOL
MIN
Low Input Leakage
IIL
High Input Leakage
IIH
TYP
MAX
UNITS
COMMENTS
-10
+10
µA
VIN = 0
-10
+10
µA
VIN = VCC
3.0
4.0
V
1.0
100
2.0
µA
nA
VCC=VSS=0
VCC=5V, VBAT=3V
0.4
V
IOL = 4 mA
V
IOH = -2 mA
+10
µA
VIN = 0 to VCC
(Note 1)
0.4
V
IOL = 8 mA
V
IOH = -8 mA
µA
VIN = 0 to VCC
(Note 1)
Input Leakage
(All I and IS buffers)
VBAT
IBAT
2.4
Standby Current
Input Leakage
O4 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
O8SR Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
Rise Time
TRT
5
ns
Fall Time
TFL
5
ns
+10
O24 Type Buffer
Low Output Level
VOL
0.4
High Output Level
VOH
2.4
Output Leakage
IOL
-10
239
+10
V
IOL = 24 mA
V
IOH = -12 mA
µA
VIN = 0 to VCC
(Note 1)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
COMMENTS
0.4
V
IOL = 16 mA
V
IOH = -16 mA
µA
VIN = 0 to VCC
(Note 1)
O16SR Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
Rise Time
TRT
5
ns
Fall Time
TFL
5
ns
+10
OD16P Type Buffer
Low Output Level
VOL
0.4
V
+10
µA
Output Leakage
IOL
-10
IOL = 16 mA
IOH = 90 µA
(Note 2)
VIN = 0 to VCC
(Note 1)
OD24 Type Buffer
Low Output Level
VOL
0.4
V
IOL = 24 mA
Output Leakage
IOL
+10
µA
VIN = 0 to VCC
(Note 1)
Low Output Level
VOL
0.4
V
IOL = 48 mA
Output Leakage
IOL
+10
µA
VIN = 0 to VCC
(Note 1)
Low Output Level
VOL
0.4
V
IOL = 2 mA
High Output Level
VOH
3.5
V
IOH = -2 mA
Output Leakage
IOL
-10
+10
µA
VIN = 0 to VCC
(Note 1)
ChiProtect
(SLCT, PE, BUSY, nACK,
nERROR)
IIL
± 10
µA
VCC = 0V
VIN = 6V Max
OD48 Type Buffer
OCLK2 Type Buffer
240
PARAMETER
SYMBOL
Backdrive
(nSTROBE, nAUTOFD, nINIT,
nSLCTIN)
MAX
UNITS
IIL
± 10
µA
VCC = 0V
VIN = 6V Max
Backdrive
(PD0-PD7)
IIL
± 10
µA
VCC = 0V
VIN = 6V Max
Suppy Current Active
ICCI
90
mA
All outputs open.
Note 1:
Note 2:
MIN
4.5
TYP
70
COMMENTS
All output leakages are measured with the current pins in high impedance. Output leakage
is measured with the low driving output off, either for a high level output or a high
impedance state.
KBCLK, KBDATA, MCLK, MDATA contain 90µA min pull-ups.
CAPACITANCE TA = 25°C; fc = 1 MHz; VCC = 5V
PARAMETER
Clock Input Capacitance
Input Capacitance
Output Capacitance
SYMBOL
CIN
MIN
LIMITS
TYP
MAX
20
UNIT
pF
CIN
10
pF
COUT
20
pF
241
TEST CONDITION
All pins except pin
under test tied to AC
ground
POWER SUPPLY OPERATIONAL MODES
Standard Operational Modes
Table 109 - Standard Operational Modes For The Power Supplies.
MODE
VBAT
VTR
VCC
RTC Only (1)
3.3V
0
0
Standby (2) (3)
3.3V
5V @ 2mA Max
0
Full Power (2)
3.3V
5V @ 2mA Max
5V
Note 1: RTC power supplied by Vbat
Note 2: RTC power supplied by VTR
Note 3: In standby mode, the following are operational: RTC, RTC Alarm 2, power control (wakeup)
logic (button input and power on) and soft power management logic.
When VCC goes away, certain registers will be powered by VTR. Similarly, when VTR goes away,
certain registers will be powered by Vbat. These registers are discussed in the Soft Power
Management and RTC Section.
Power Supply Non-Standard Modes
Table 110 - Non-Standard Operational Modes For The Power Supplies.
NON-STANDARD MODE
VBAT
VTR
VCC
NS1
0
5V @ 2mA Max
0
NS2
0
5V @ 2mA Max
5V
NS3
0
0
5V
NS4
3.3V
0
5V
242
TIMING DIAGRAMS
For the Timing Diagrams shown, the following capacitive loads are used.
CAPACITANCE
TOTAL (pF)
240
240
120
120
50
50
50
50
50
240
240
240
240
240
240
240
240
100
100
100
100
100
100
100
240
240
240
240
240
240
240
240
240
240
240
240
240
NAME
SD[0:7]
IOCHRDY
IRQ[1,3:12,14,15]
DRQ[0:3]
HCLK
16CLK
CLK01
CLK02
CLK03
nWGATE
nWDATA
nHDSEL
nDIR
nSTEP
nDS[1:0]
nMTR[1:0]
DRVDEN[1:0]
TXD1
nRTS1
nDTR1
TXD2
nRTS2
nDTR2
nIDE1_OE
nHDCS0
nHDCS1
nIOROP
nIOWOP
nHDCS2
nHDCS3
PD[0:7]
nSLCTIN
nINIT
nALF
nSTB
KDAT
KCLK
243
CAPACITANCE
TOTAL (pF)
240
240
100
100
100
100
NAME
MDAT
MCLK
nPowerOn
Button_In
GP1[0:7], GP2[0:5]
RD[0:7]
244
B u tto n _ I n
tF
tR
FIGURE 15A - BUTTON INPUT TIMING
NAME
tR, tF
DESCRIPTION
MIN
TYP
MAX
UNITS
0.5
µs
MAX
4
UNITS
s
s
4
s
Button_In Rise/Fall Time
B u tto n _ In
t1
R e le a s e
n P o w e rO n
t2
B la n k in g P e rio d
t3
Vcc
FIGURE 15B - BUTTON OVERRIDE TIMING
NAME
t1
t2
t3
DESCRIPTION
Button_In Hold Time For Override Event
Button _In Low To nPowerOn Tristate and Vcc Low and
Start of Blanking Period
Blanking Period After Release of Button_In
245
MIN
4
TYP
t3
SAx
t4
SD<7:0>
nIOW
t1
t2
t5
FIGURE 16 - IOW TIMING FOR PORT 92
IOW TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
SAx Valid to nIOW Asserted
40
ns
t2
SDATA Valid to nIOW Asserted
0
ns
t3
nIOW Asserted to SAx Invalid
10
ns
t4
nIOW Deasserted to DATA Invalid
t5
nIOW Deasserted to nIOW or nIOR Asserted
246
0
ns
100
ns
t 1
t 2
V c c
t 3
A ll H o s t
A c c e s s e s
FIGURE 17 - POWER-UP TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
Vcc Slew from 4.5V to 0V
300
µs
t2
Vcc Slew from 0V to 4.5V
100
µs
t3
All Host Accesses After Powerup (Note 1)
125
Note 1: Internal write-protection period after Vcc passes 4.5 volts on power-up
247
500
µs
t10
AEN
t3
SA[x], nCS
t2
t1
t4
nIOW
t6
t11
t5
SD[x]
DATA VALID
GP I/O
t7
FINTR
t8
PINTR
t9
IBF
FIGURE 18 - ISA WRITE
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
SA[x], nCS and AEN Valid to nIOW Asserted
10
ns
t2
nIOW Asserted to nIOW Deasserted
80
ns
t3
nIOW Asserted to SA[x], nCS Invalid
10
ns
t4
SD[x] Valid to nIOW Deasserted
45
t5
SD[x] Hold from nIOW Deasserted
t6
nIOW Deasserted to nIOW Asserted
t7
nIOW Deasserted to FINTR Deasserted (Note 2)
55
ns
t8
nIOW Deasserted to PINTER Deasserted (Note 3)
260
ns
t9
IBF (Internal Signal) Asserted from nIOW Deasserted
40
ns
t10
nIOW Deasserted to AEN Invalid
t11
nIOW Deasserted to GPI/O Out Valid
ns
0
25
ns
10
ns
100
Note 1: If ACCESS.bus is used at 12 MHz, use 100 ns.
Note 2: FINTR refers to the IRQ used by the floppy disk.
Note 3: PINTR refers to the IRQ used by the parallel port
248
ns
ns
t13
AEN
t3
SA[x], nCS
t1
t7
t2
t6
nIOR
t4
t5
SD[x]
DATA VALID
PD[x], nERROR,
PE, SLCT, ACK, BUSY
t10
FINTER
t9
PINTER
t11
PCOBF
t12
AUXOBF1
t8
nIOR/nIOW
FIGURE 19 - ISA READ
SEE TIMING PARAMETERS ON NEXT PAGE
249
ISA READ TIMING
DESCRIPTION
NAME
MIN
TYP
MAX
UNITS
t1
SA[x], nCS and AEN valid to nIOR asserted
10
ns
t2
nIOR Asserted to nIOR Deasserted
50
ns
t3
nIORAsserted to SA[x], nCS Invalid
10
ns
t4
nIOR Asserted to Data Valid
t5
Data Hold/float from nIOR Deasserted
10
t6
nIOR Deasserted
25
ns
t8
nIOR Aserted after nIOW Deasserted
80
ns
t8
nIOR/nIOR, nIOW/nIOW Transfers from/to ECP FIFO
150
ns
t7
Parallel Port Setup to nIOR Asserted
20
ns
t9
nIOR Asserted to PINTER Deasserted
55
ns
t10
nIOR Deasserted to FINTER Deasserted
260
ns
t11
nIOR Deasserted to PCOBF Deasserted (Notes 4,6)
80
ns
t12
nIOR Deasserted to AUXOBF1 Deasserted (Notes 5,6)
80
ns
t13
nIOW Deasserted to AEN Invalid
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
10
If ACCESS.bus is used at a clock rate below 24 MHz, use 100 ns.
FINTR refers to the IRQ used by the floppy disk.
PINTR refers to the IRQ used by the parallel port.
PCOBF is used for the Keyboard IRQ.
AUXOBF1 is used for the Mouse IRQ.
Applies only if deassertion is performed in hardware.
250
50
ns
25
ns
ns
t2
PCOBF
t1
AUXOBF1
nWRT
t3
IBF
nRD
FIGURE 20 - INTERNAL 8042 CPU TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nWRT Deasserted to AUXOBF1 Asserted (Notes 1,2)
40
ns
t2
nWRT Deasserted to PCOBF Asserted (Notes 1,3)
40
ns
t3
nRD Dasserted to IBF Deasserted (Note 1)
40
ns
Note 1: IBF, nWRT and nRD are internal signals.
Note 2: PCOBF is used for the Keyboard IRQ.
Note 3: AUXOBF1 is used for the Mouse IRQ.
251
t1
t2
t2
X1K
FIGURE 21A - INPUT CLOCK TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
Clock Cycle Time for 14.318 MHZ
70
ns
t2
Clock High Time/Low Time for 14.318 MHz
35
ns
t1
Clock Cycle Time for 32 KHz
31.25
µs
t2
Clock High Time/Low Time for 32 KHz
16.53
Clock Rise Time/Fall Time (not shown)
µs
5
ns
t4
RESET
FIGURE 21B - RESET TIMING
NAME
t4
DESCRIPTION
MIN
RESET Width (Note 1)
1.5
TYP
MAX
UNITS
µs
Note 1: The RESET width is dependent upon the processor clock. The RESET must be active while
the clock is running and stable.
252
IDEx_IRQ
t1
t2
IRQx
FIGURE 22 - IRQ TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
IDE_IRQ Low-High Edge to IRQ Low-High
Edge Propagation Delay. Edge High Type
Interrupt Selected.
30
ns
t2
IDE_IRQ High-Low Edge to IRQ High-Low
Edge Propagation Delay. Edge High Type
Interrupt Selected.
30
ns
Note:
IDE IRQ input and pass-through IRQ timing
Definition:
IDE_ IRQ is the Interrupt request input from an IDE Hard Drive which is defined as a
low to high edge type interrupt held high until the interrupt is serviced.
253
nIOR
nIOROP
t2
t2
t3
t3
nIOW
nIOW O P
FIGURE 23 - nIOROP, nIOWOP TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t2
nIOR in to nIOROP Output
25
ns
t3
nIOW in to nIOWOP Output
25
ns
254
nROMCS
nROMOE
t2
t7 N o t e 2
t1
t3
t2
t8
t3
RD[x]
t4
Note 1
t5
t6
S D [x]
FIGURE 24 - ROM INTERFACE TIMING
Note 1: RD[x] driven by FDC37C93x, SD[x] driven by system
Note 2: RD[x] driven by ROM, SD[x] driven by FDC37C93xAPM
NAME
MAX
UNITS
t1
SD[x] Valid to RD[x] Valid
DESCRIPTION
MIN
25
ns
t2
nROMCS Active to RD[X] Driven
25
ns
t3
nROMCS Inactive to RD[X] Float
25
ns
t4
RD[x] Valid to SD[x] Valid
25
ns
t5
nROMCS Active to SD[X] Driven
25
ns
t6
nROMCS Inactive to SD[X] Float
25
ns
t7
nROMOE Active to RD[x] Float
25
ns
t8
nROMOE Inactive to RD[x] Driven
25
ns
Note 1: Outputs have a 50 pf load.
255
TYP
t15
AEN
t16
t3
t2
FDRQ,
PDRQ
t1
t4
nDACK
t12
t14
t11
t6
t5
t8
nIOR
or
nIOW
t10
t9
t7
DATA
(DO-D7)
DATA VALID
t13
TC
FIGURE 25A - DMA TIMING (SINGLE TRANSFER MODE)
NAME
DESCRIPTION
t1
nDACK Delay Time from FDRQ High
t2
DRQ Reset Delay from nIOR or nIOW
t3
FDRQ Reset Delay from nDACK Low
t4
nDACK Width
t5
MIN
TYP
MAX
0
UNITS
ns
100
ns
100
ns
150
ns
nIOR Delay from FDRQ High
0
ns
t6
nIOW Delay from FDRQ High
0
t7
Data Access Time from nIOR Low
t8
Data Set Up Time to nIOW High
40
t9
Data to Float Delay from nIOR High
10
t10
Data Hold Time from nIOW High
10
ns
t11
nDACK Set Up to nIOW/nIOR Low
5
ns
t12
nDACK Hold after nIOW/nIOR High
10
ns
t13
TC Pulse Width
60
ns
t14
AEN Set Up to nIOR/nIOW
40
ns
t15
AEN Hold from nDACK
10
ns
t16
TC Active to PDRQ Inactive
ns
100
ns
60
100
256
ns
ns
ns
t15
AEN
t16
t3
t2
FDRQ,
PDRQ
t1
t4
nDACK
t12
t14
t11
t6
t8
t5
nIOR
or
nIOW
t10
t9
t7
DATA
(DO-D7)
DATA VALID
DATA VALID
t13
TC
FIGURE 25B - DMA TIMING (BURST TRANSFER MODE)
NAME
DESCRIPTION
MIN
t1
nDACK Delay Time from FDRQ High
t2
DRQ Reset Delay from nIOR or nIOW
t3
FDRQ Reset Delay from nDACK Low
t4
nDACK Width
t5
t6
t7
Data Access Time from nIOR Low
t8
Data Set Up Time to nIOW High
40
TYP
MAX
0
UNITS
ns
100
ns
100
ns
150
ns
nIOR Delay from FDRQ High
0
ns
nIOW Delay from FDRQ High
0
ns
100
ns
ns
t9
Data to Float Delay from nIOR High
10
t10
Data Hold Time from nIOW High
10
60
ns
t11
nDACK Set Up to nIOW/nIOR Low
5
ns
t12
nDACK Hold after nIOW/nIOR High
10
ns
t13
TC Pulse Width
60
ns
t14
AEN Set Up to nIOR/nIOW
40
ns
t15
AEN Hold from nDACK
10
ns
t16
TC Active to PDRQ Inactive
100
257
ns
ns
t3
nDIR
t4
t1
t2
nSTEP
t5
nDS0-3
t6
nINDEX
t7
nRDATA
t8
nWDATA
nIOW
t9
t9
nDS0-1,
MTR0-1
FIGURE 26 - DISK DRIVE TIMING (AT MODE ONLY)
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nDIR Set Up to STEP Low
4
X*
t2
nSTEP Active Time Low
24
X*
t3
nDIR Hold Time after nSTEP
96
X*
t4
nSTEP Cycle Time
132
X*
t5
nDS0-1 Hold Time from nSTEP Low
20
X*
t6
nINDEX Pulse Width
2
X*
t7
nRDATA Active Time Low
40
ns
t8
nWDATA Write Data Width Low
.5
Y*
t9
nDS0-1, MTRO-1 from End of nIOW
25
ns
*X specifies one MCLK period and Y specifies one WCLK period.
MCLK = 16 x Data Rate (at 500 kbps MCLK = 8 MHz)
WCLK = 2 x Data Rate (at 500 kbps WCLK = 1 MHz)
258
nIOW
t1
nRTSx,
nDTRx
t5
IRQx
nCTSx,
nDSRx,
nDCDx
t6
t2
t4
IRQx
nIOW
t3
IRQx
nIOR
nRIx
FIGURE 27 - SERIAL PORT TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nRTSx, nDTRx Delay from nIOW
200
ns
t2
IRQx Active Delay from nCTSx, nDSRx, nDCDx
100
ns
t3
IRQx Inactive Delay from nIOR (Leading Edge)
120
ns
t4
IRQx Inactive Delay from nIOW (Trailing Edge)
125
ns
t5
IRQx Inactive Delay from nIOW
100
ns
t6
IRQx Active Delay from nRIx
100
ns
10
259
nAEN
A0-A9
t3
t2
t1
nIDEENLO,
nIDEENHI,
nHDCSx,
nGAMECS
FIGURE 28 - IDE INTERFACE TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nIDEENLO, nIDEENHI, nGAMECS, nHDCSx Delay
from nAEN
40
ns
t2
nIDEENLO, nIDEENHI, nGAMECS, nHDCSx Delay
from A0 - A9
40
ns
t3
nIDEENLO Delay from nIDEENHI, AEN
40
ns
260
PD0- PD7
t6
nIOW
t1
nINIT, nSTROBE.
nAUTOFD, SLCTIN
nACK
t2
nPINTR
(SPP)
t4
PINTR
(ECP or EPP Enabled)
t3
nFAULT (ECP)
nERROR
(ECP)
t5
t2
t3
PINTR
FIGURE 29 - PARALLEL PORT TIMING
NAME
DESCRIPTION
MIN
t1
PD0-7, nINIT, nSTROBE, nAUTOFD Delay from
nIOW
t2
PINTR Delay from nACK, nFAULT
t3
PINTR Active Low in ECP and EPP Modes
t4
TYP
MAX
UNITS
100
ns
60
ns
300
ns
PINTR Delay from nACK
105
ns
t5
nERROR Active to PINTR Active
105
ns
t6
PD0 - PD7 Delay from IOW Active
100
ns
Note:
PINTR refers to the IRQ used by the parallel port.
261
200
t18
A0-A10
t9
SD<7:0>
t17
t8
nIOW
t12
t10
IOCHRDY
nWRITE
t19
t11
t13
t22
t20
t2
t1
t5
PD<7:0>
t14
nDATAST
t16
t3
t4
nADDRSTB
t6
t15
t7
nWAIT
t21
PDIR
FIGURE 30A - EPP 1.9 DATA OR ADDRESS WRITE CYCLE
SEE TIMING PARAMETERS ON NEXT PAGE
262
FIGURE 30B - EPP 1.9 DATA OR ADDRESS WRITE CYCLE TIMING
NAME
MAX
UNITS
t1
nIOW Asserted to PDATA Valid
DESCRIPTION
MIN
0
TYP
50
ns
t2
nWAIT Asserted to nWRITE Change (Note 1)
60
185
ns
t3
nWRITE to Command Asserted
5
35
ns
t4
nWAIT Deasserted to Command Deasserted
(Note 1)
60
190
ns
t5
nWAIT Asserted to PDATA Invalid (Note 1)
0
t6
Time Out
10
t7
Command Deasserted to nWAIT Asserted
0
ns
t8
SDATA Valid to nIOW Asserted
10
ns
t9
nIOW Deasserted to DATA Invalid
0
ns
t10
nIOW Asserted to IOCHRDY Asserted
0
24
ns
t11
nWAIT Deasserted to IOCHRDY Deasserted
(Note 1)
60
160
ns
t12
IOCHRDY Deasserted to nIOW Deasserted
10
t13
nIOW Asserted to nWRITE Asserted
0
70
ns
t14
nWAIT Asserted to Command Asserted (Note 1)
60
210
ns
t15
Command Asserted to nWAIT Deasserted
0
10
µs
t16
PDATA Valid to Command Asserted
10
ns
t17
Ax Valid to nIOW Asserted
40
ns
t18
nIOW Asserted to Ax Invalid
10
ns
t19
nIOW Deasserted to nIOW or nIOR Asserted
40
ns
t20
nWAIT Asserted to nWRITE Asserted (Note 1)
60
t21
nWAIT Asserted to PDIR Low
0
ns
t22
PDIR Low to nWRITE Asserted
0
ns
ns
12
ns
185
Note 1: nWAIT must be filtered to compensate for ringing on the parallel bus cable.
considered to have settled after it does not transition for a minimum of 50 nsec.
263
µs
ns
WAIT is
t20
A0-A10
IOR
t19
t11
t13
t22
t12
SD<7:0>
IOCHRDY
t18
t10
t8
t24
t23
t27
PDIR
t9
t21
t17
nWRITE
t2
t25
PData bus driven
by peripheral
t5
t4
t16
PD<7:0>
t28
t26
t1
DATASTB
t14
t3
ADDRSTB
t15
t7
nWAIT
FIGURE 31A - EPP 1.9 DATA OR ADDRESS READ CYCLE
SEE TIMING PARAMETERS ON NEXT PAGE
264
t6
FIGURE 31B - EPP 1.9 DATA OR ADDRESS READ CYCLE TIMING PARAMETERS
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
PDATA Hi-Z to Command Asserted
0
30
ns
t2
nIOR Asserted to PDATA Hi-Z
0
50
ns
t3
nWAIT Deasserted to Command Deasserted
(Note 1)
60
180
ns
t4
Command Deasserted to PDATA Hi-Z
0
t5
Command Asserted to PDATA Valid
0
ns
t6
PDATA Hi-Z to nWAIT Deasserted
0
µs
t7
PDATA Valid to nWAIT Deasserted
0
t8
nIOR Asserted to IOCHRDY Asserted
0
t9
nWRITE Deasserted to nIOR Asserted (Note 2)
0
t10
nWAIT Deasserted to IOCHRDY Deasserted
(Note 1)
60
t11
IOCHRDY Deasserted to nIOR Deasserted
0
t12
nIOR Deasserted to SDATA Hi-Z (Hold Time)
0
t13
PDATA Valid to SDATA Valid
t14
nWAIT Asserted to Command Asserted
t15
ns
ns
24
ns
160
ns
ns
ns
40
ns
0
75
ns
0
195
ns
Time Out
10
12
µs
t16
nWAIT Deasserted to PDATA Driven (Note 1)
60
190
ns
t17
nWAIT Deasserted to nWRITE Modified (Notes 1,2)
60
190
ns
t18
SDATA Valid to IOCHRDY Deasserted (Note 3)
0
85
t19
Ax Valid to nIOR Asserted
40
t20
nIOR Deasserted to Ax Invalid
10
10
t21
nWAIT Asserted to nWRITE Deasserted
0
185
t22
nIOR Deasserted to nIOW or nIOR Asserted
40
t23
nWAIT Asserted to PDIR Set (Note 1)
60
t24
PDATA Hi-Z to PDIR Set
0
t25
nWAIT Asserted to PDATA Hi-Z (Note 1)
60
180
ns
t26
PDIR Set to Command
0
20
ns
t27
nWAIT Deasserted to PDIR Low (Note 1)
60
180
ns
t28
nWRITE Deasserted to Command
1
Note 1:
Note 2:
Note 3:
nWAIT is considered to have settled after it does not transition for a minimum of 50 ns.
When not executing a write cycle, EPP nWRITE is inactive high.
85 is true only if t7 = 0.
265
ns
ns
ns
ns
ns
185
ns
ns
ns
t18
A0-A10
t9
SD<7:0>
nIOW
t17
t8
t6
t19
t12
t10
t20
IOCHRDY
t11
t13
t2
t1
t5
nWRITE
PD<7:0>
t16
t3
t4
nDATAST
nADDRSTB
t21
nWAIT
PDIR
FIGURE 32A - EPP 1.7 DATA OR ADDRESS WRITE CYCLE
SEE TIMING PARAMETERS ON NEXT PAGE
266
FIGURE 32B - EPP 1.7 DATA OR ADDRESS WRITE CYCLE PARAMETERS
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nIOW Asserted to PDATA Valid
0
50
ns
t2
Command Deasserted to nWRITE Change
0
40
ns
t3
nWRITE to Command
5
35
ns
t4
nIOW Deasserted to Command Deasserted (Note 2)
50
ns
t5
Command Deasserted to PDATA Invalid
50
t6
Time Out
10
t8
SDATA Valid to nIOW Asserted
10
ns
t9
nIOW Deasserted to DATA Invalid
0
ns
t10
nIOW Asserted to IOCHRDY Asserted
0
t11
nWAIT Deasserted to IOCHRDY Deasserted
t12
IOCHRDY Deasserted to nIOW Deasserted
10
t13
nIOW Asserted to nWRITE Asserted
0
50
ns
t16
PDATA Valid to Command Asserted
10
35
ns
t17
Ax Valid to nIOW Asserted
40
t18
nIOW Deasserted to Ax Invalid
10
µs
t19
nIOW Deasserted to nIOW or nIOR Asserted
100
ns
t20
nWAIT Asserted to IOCHRDY Deasserted
t21
Command Deasserted to nWAIT Deasserted
ns
12
24
40
ns
ns
ns
ns
45
0
µs
ns
ns
Note 1: nWRITE is controlled by clearing the PDIR bit to "0" in the control register before performing
an EPP Write.
Note 2: The number is only valid if nWAIT is active when IOW goes active.
267
t20
A0-A10
t15
t11
t19
t22
nIOR
t13
t12
SD<7:0>
t8
t10
t3
IOCHRDY
nWRITE
t5
t4
PD<7:0>
t23
t2
nDATASTB
nADDRSTB
t21
nWAIT
PDIR
FIGURE 33A - EPP 1.7 DATA OR ADDRESS READ CYCLE
SEE TIMING PARAMETERS ON NEXT PAGE
268
FIGURE 33B - EPP 1.7 DATA OR ADDRESS READ CYCLE PARAMETERS
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
50
ns
40
ns
t2
nIOR Deasserted to Command Deasserted
t3
nWAIT Asserted to IOCHRDY Deasserted
0
t4
Command Deasserted to PDATA Hi-Z
0
t5
Command Asserted to PDATA Valid
0
t8
nIOR Asserted to IOCHRDY Asserted
24
ns
t10
nWAIT Deasserted to IOCHRDY Deasserted
50
ns
t11
IOCHRDY Deasserted to nIOR Deasserted
0
t12
nIOR Deasserted to SDATA High-Z (Hold Time)
0
40
ns
t13
PDATA Valid to SDATA Valid
40
ns
t15
Time Out
10
12
µs
t19
Ax Valid to nIOR Asserted
40
ns
t20
nIOR Deasserted to Ax Invalid
10
ns
t21
Command Deasserted to nWAIT Deasserted
0
ns
t22
nIOR Deasserted to nIOW or nIOR Asserted
40
ns
t23
nIOR Asserted to Command Asserted
Note:
ns
ns
ns
55
ns
WRITE is controlled by setting the PDIR bit to "1" in the control register before performing an
EPP Read.
269
ECP PARALLEL PORT TIMING
The host then sets HostClk (nStrobe) high. The
peripheral then accepts the data and sets
PeriphAck (Busy) low, completing the transfer.
This sequence is shown in Figure 35.
Parallel Port FIFO (Mode 101)
The standard parallel port is run at or near the
peak 500 Kbps allowed in the forward direction
using DMA.
The state machine does not
examine nACK and begins the next transfer
based on Busy. Refer to Figure 34.
The timing is designed to provide three cable
round-trip times for data setup if Data is driven
simultaneously with HostClk (nStrobe).
ECP Parallel Port Timing
Reverse-Idle Phase
The timing is designed to allow operation at
approximately 2.0 Mbps over a 15ft cable. If a
shorter cable is used then the bandwidth will
increase.
The peripheral has no data to send and keeps
PeriphClk high. The host is idle and keeps
HostAck low.
Forward-Idle
Reverse Data Transfer Phase
When the host has no data to send it keeps
HostClk (nStrobe) high and the peripheral will
leave PeriphClk (Busy) low.
The interface transfers data and commands
from the peripheral to the host using an interlocked HostAck and PeriphClk.
Forward Data Transfer Phase
The Reverse Data Transfer Phase may be
entered from the Reverse-Idle Phase. After the
previous byte has beed accepted the host sets
HostAck (nALF) low. The peripheral then sets
PeriphClk (nACK) low when it has data to send.
The data must be stable for the specified setup
time prior to the falling edge of PeriphClk. When
the host is ready to accept a byte it sets
HostAck (nALF) high to acknowledge the
handshake. The peripheral then sets PeriphClk
(nACK) high. After the host has accepted the
data it sets HostAck (nALF) low, completing the
transfer. This sequence is shown in Figure 36.
The interface transfers data and commands
from the host to the peripheral using an interlocked PeriphAck and HostClk. The peripheral
may indicate its desire to send data to the host
by asserting nPeriphRequest.
The Forward Data Transfer Phase may be
entered from the Forward-Idle Phase. While in
the Forward Phase the peripheral may
asynchronously assert the nPeriphRequest
(nFault) to request that the channel be reversed.
When the peripheral is not busy it sets
PeriphAck (Busy) low. The host then sets
HostClk (nStrobe) low when it is prepared to
send data. The data must be stable for the
specified setup time prior to the falling edge of
HostClk. The peripheral then sets PeriphAck
(Busy) high to acknowledge the handshake.
Output Drivers
To facilitate higher performance data transfer,
the use of balanced CMOS active drivers for
critical signals (Data, HostAck, HostClk,
PeriphAck, PeriphClk) are used ECP Mode.
Because the use of active drivers can present
compatibility problems in Compatible Mode (the
control signals, by tradition, are specified as
270
open-collector), the drivers are dynamically
changed from open-collector to totem-pole. The
timing for the
dynamic
driver change is
specified in
then
IEEE 1284 Extended
Capabilities Port Protocol and ISA Interface
Standard, Rev. 1.14, July 14, 1993, available
from Microsoft. The dynamic driver change
must be implemented properly to prevent
glitching the outputs.
t6
t3
PDATA
t1
nSTROBE
t2
t5
t4
BUSY
FIGURE 34 - PARALLEL PORT FIFO TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
DATA Valid to nSTROBE Active
600
ns
t2
nSTROBE Active Pulse Width
600
ns
t3
DATA Hold from nSTROBE Inactive (Note 1)
450
t4
nSTROBE Active to BUSY Active
t5
BUSY Inactive to nSTROBE Active
680
ns
t6
BUSY Inactive to PDATA Invalid (Note 1)
80
ns
ns
500
ns
Note 1: The data is held until BUSY goes inactive or for time t3, whichever is longer. This only
applies if another data transfer is pending. If no other data transfer is pending, the data is
held indefinitely.
271
t3
nAUTOFD
t4
PDATA<7:0>
t2
t1
t7
t8
nSTROBE
BUSY
t6
t5
t6
FIGURE 35 - ECP PARALLEL PORT FORWARD TIMING
NAME
MAX
UNITS
t1
nAUTOFD Valid to nSTROBE Asserted
DESCRIPTION
MIN
0
TYP
60
ns
t2
PDATA Valid to nSTROBE Asserted
0
60
ns
t3
BUSY Deasserted to nAUTOFD Changed
(Notes 1,2)
80
180
ns
t4
BUSY Deasserted to PDATA Changed (Notes 1,2)
80
180
ns
t5
nSTROBE Deasserted to Busy Asserted
0
t6
nSTROBE Deasserted to Busy Deasserted
0
t7
BUSY Deasserted to nSTROBE Asserted (Notes 1,2)
80
200
ns
t8
BUSY Asserted to nSTROBE Deasserted (Note 2)
80
180
ns
ns
ns
Note 1: Maximum value only applies if there is data in the FIFO waiting to be written out.
Note 2: BUSY is not considered asserted or deasserted until it is stable for a minimum of 75 to 130
ns.
272
t2
PDATA<7:0>
t1
t5
t6
nACK
t4
t3
t4
nAUTOFD
FIGURE 36 - ECP PARALLEL PORT REVERSE TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
0
UNITS
t1
PDATA Valid to nACK Asserted
ns
t2
nAUTOFD Deasserted to PDATA Changed
0
t3
nACK Asserted to nAUTOFD Deasserted
(Notes 1,2)
80
200
ns
t4
nACK Deasserted to nAUTOFD Asserted (Note 2)
80
200
ns
t5
nAUTOFD Asserted to nACK Asserted
0
ns
t6
nAUTOFD Deasserted to nACK Deasserted
0
ns
ns
Note 1: Maximum value only applies if there is room in the FIFO and terminal count has not been
received. ECP can stall by keeping nAUTOFD low.
Note 2: nACK is not considered asserted or deasserted until it is stable for a minimum of 75 to 130
ns.
273
AB_DATA
tBUF
tLOW
tR
tHD;STA
tF
AB_CLK
tHD;STA
tHD;DAT
tHIGH
tSU;DAT
tSU;STO
tSU;STA
FIGURE 37 - ACCESS.BUS TIMING
SYMBOL
PARAMETER
MIN.
TYP.
MAX.
UNIT
100
KHz
fSCL
SCL Clock Frequency
tBUF
Bus Free Time
4.7
µs
tSU;STA
START Condition Setup Time
4.7
µs
tHD;STA
START Condition Hold Time
4.0
µs
tLOW
SCL LOW Time
4.7
µs
tHIGH
SCL HIGH Time
4.0
µs
tR
SCL and SDA Rise Time
1.0
µs
tF
SCL and SDA Fall Time
0.3
µs
tSU;DAT
Data Set-Up Time
tHD;DAT
Data Hold Time
tSU;STO
STOP Condition Setup Time
274
250
µs
0
µs
4.0
µs
DATA
0
1
0
t2
t1
t2
t1
1
0
0
1
1
0
1
1
IRRX
nIRRX
Parameter
t1
t1
t1
t1
t1
t1
t1
t2
t2
t2
t2
t2
t2
t2
Pulse Width at 115kbaud
Pulse Width at 57.6kbaud
Pulse Width at 38.4kbaud
Pulse Width at 19.2kbaud
Pulse Width at 9.6kbaud
Pulse Width at 4.8kbaud
Pulse Width at 2.4kbaud
Bit Time at 115kbaud
Bit Time at 57.6kbaud
Bit Time at 38.4kbaud
Bit Time at 19.2kbaud
Bit Time at 9.6kbaud
Bit Time at 4.8kbaud
Bit Time at 2.4kbaud
min
typ
max
units
1.4
1.4
1.4
1.4
1.4
1.4
1.4
1.6
3.22
4.8
9.7
19.5
39
78
8.68
17.4
26
52
104
208
416
2.71
3.69
5.53
11.07
22.13
44.27
88.55
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
Note1: Receive Pulse Detection Criteria: A received pulse is considered detected if the
received pulse is a minimum of 1.41µs.
Note 2: IRRX: L5, CRF1 Bit 0: 1 = RCV active low
nIRRX: L5, CRF1 Bit 0: 0 = RCV active high (default)
Note 3: This polarity assumes that the GPIO has not been programmed for inverted.
FIGURE 38 - IrDA RECEIVE TIMING
275
DATA
0
1
0
t2
t1
t2
t1
1
0
0
1
1
0
1
1
IRTX
n IRTX
t1
t1
t1
t1
t1
t1
t1
t2
t2
t2
t2
t2
t2
t2
Parameter
min
typ
max
units
Pulse W idth at 115kbaud
Pulse W idth at 57.6kbaud
Pulse W idth at 38.4kbaud
Pulse W idth at 19.2kbaud
Pulse W idth at 9.6kbaud
Pulse W idth at 4.8kbaud
Pulse W idth at 2.4kbaud
Bit Time at 115kbaud
Bit Time at 57.6kbaud
Bit Time at 38.4kbaud
Bit Time at 19.2kbaud
Bit Time at 9.6kbaud
Bit Time at 4.8kbaud
Bit Time at 2.4kbaud
1.41
1.41
1.41
1.41
1.41
1.41
1.41
1.6
3.22
4.8
9.7
19.5
39
78
8.68
17.4
26
52
104
208
416
2.71
3.69
5.53
11.07
22.13
44.27
88.55
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
Notes:
1. IrDA @ 115k is HPSIR compatible. IrDA @ 2400 will allow compatibility with HP95LX
and 48SX.
2. IRTX: L5, CRF1 Bit 1: 1 = XMIT active low (default)
nIRTX: L5, CRF1 Bit 1: 0 = XMIT active high
3. This polarity assumes that the GPIO has not been programmed for inverted.
FIGURE 39 - IrDA TRANSMIT TIMING
276
DATA
0
1
t1
0
1
0
0
1
1
0
1
1
t2
IRRX
n IRRX
t3
t4
t5
t6
MIRRX
nMIRRX
Parameter
min
typ
max
units
t1
Modulated Output Bit Time
µs
t2
Off Bit Time
µs
t3
Modulated Output "On"
0.8
1
1.2
µs
t4
Modulated Output "Off"
0.8
1
1.2
µs
t5
Modulated Output "On"
0.8
1
1.2
µs
t6
Modulated Output "Off"
0.8
1
1.2
µs
Note 1: IRRX:
L5, CRF1 Bit 0: 1 = RCV active low
nIRRX: L5, CRF1 Bit 0: 0 = RCV active high (default)
MIRRX, nMIRRX are the modulated outputs
Note 2: This polarity assumes that the GPIO has not been programmed for inverted.
FIGURE 40 - AMPLITUDE SHIFT KEYED IR RECEIVE TIMING
277
DATA
0
1
t1
0
1
0
0
1
1
0
1
1
t2
IRTX
nIRTX
t3
t4
t5
t6
MIRTX
nMIRTX
Parameter
min
typ
max
units
t1
Modulated Output Bit Time
t2
Off Bit Time
t3
Modulated Output "On"
0.8
1
1.2
µs
t4
Modulated Output "Off"
0.8
1
1.2
µs
t5
Modulated Output "On"
0.8
1
1.2
µs
t6
Modulated Output "Off"
0.8
1
1.2
µs
µs
µs
Note 1: IRTX: L5, CRF1 Bit 1: 1 = XMIT active low
(default)nIRTX: L5, CRF1 Bit 1: 0 = XMIT active
high
MIRTX, nMIRTX are the modulated
outputs
Note 2: This polarity assumes that the GPIO has not been programmed for inverted.
FIGURE 41 - AMPLITUDE SHIFT KEYED IR TRANSMIT TIMING
278
D
DETAIL "A"
120
R1
R2
3
D1
81
121
80
0
L
5
L1
E
E1
W
2
7
D1/4
e
E1/4
160
41
1
A
40
A2
TD / TE
4
H
1
0.10
0
A1
SEE DETAIL "A"
-C-
M IN
NOM
A
MAX
Notes:
4.07
1)
Coplanarity is 0.100 mm maximum
2)
Tolerance on the position of the leads is 0.120
mm maximum
3)
Package body dimensions D1 and E1 do not
include the mold protrusion. Maximum mold
protrusion is 0.25 mm
A1
0.05
0.5
A2
3.10
3.67
D
30.95
31.20
D1
27.90
28.00
31.45
28.10
E3
30.95
31.20
31.45
E1
27.90
28.00
28.10
4)
H
L
0.10
0.65
Dimensions T D and TE are important for testing
by robotic handler
0.80
0.200
0.95
5)
Dimensions for foot length L w hen measured at
the centerline of the leads are given at the table
Dimension for foot length L w hen measured at
the gauge plane 0.25 mm above the seating
plane is 0.78 - 1.03 mm
6)
Controlling dimension: millimeter
7)
Details of pin 1 identifier are optional but must
be located w ithin the zone indicated
1.60
L1
e
0
W
R1
R2
TD
TE
0.65BSC
0
0.20
7
0.40
0.20
0.30
30.45
30.45
FIGURE 42 - 160 PIN QFP PACKAGE OUTLINES
279
1999© STANDARD MICROSYSTEMS
CORP.
Circuit diagrams utilizing SMSC products are included as a means of illustrating
typical applications; consequently complete information sufficient for construction
purposes is not necessarily given. The information has been carefully checked and
is believed to be entirely reliable. However, no responsibility is assumed for
inaccuracies. Furthermore, such information does not convey to the purchaser of the
semiconductor devices described any licenses under the patent rights of SMSC or
others. SMSC reserves the right to make changes at any time in order to improve
design and supply the best product possible. SMSC products are not designed,
intended, authorized or warranted for use in any life support or other application
where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC
and further testing and/or modification will be fully at the risk of the customer.
FDC37C93xAPM Rev. 11/02/99