FDC37B78x
Super I/O Controller with ACPI Support,
Real Time Clock and Consumer IR
FEATURES
5 Volt Operation
PC98/99 and ACPI 1.0 Compliant
Battery Back-up for Wake-Events
ISA Plug-and-Play Compatible Register Set
12 IRQ Options
15 Serial IRQ Options
16 Bit Address Qualification
Four DMA Options
12mA AT Bus Drivers
BIOS Buffer
20 GPI/O Pins
32KHz Standby Clock Output
Soft Power Management
ACPI/PME Support
SCI/SMI Support
Watchdog timer
Power Button Override Event
Either Edge Triggered Interrupts
Intelligent Auto Power Management
Shadowed Write-only Registers
Programmable Wake-up Event Interface
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
Day of Month Alarm, Century Byte
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
5μA Standby Battery Current (max)1
2.88MB Super I/O Floppy Disk Controller
Relocatable to 480 Different Addresses
Licensed CMOS 765B Floppy Disk
Controller
Advanced Digital Data Separator
SMSC's Proprietary 82077AA
Compatible Core
Sophisticated Power Control Circuitry
(PCC) Including Multiple Powerdown
Modes for Reduced Power
Consumption
Supports Two Floppy Drives Directly
Software Write Protect
FDC on Parallel Port
Low Power CMOS Design
Supports Vertical Recording Format
16 Byte Data FIFO
100% IBM Compatibility
Detects All Overrun and Underrun
Conditions
24mA Drivers and Schmitt Trigger
Inputs
Enhanced FDC 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
-
1
Serial Ports
Relocatable to 480 Different Addresses
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 1.0, Consumer IR, HP-SIR, ASKIR Support
Ring Wake Filter
Multi-Mode Parallel Port with ChiProtect
Relocatable to 480 Different Addresses
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
14 mA Output Drivers
128 Pin QFP package, lead-free RoHS
compliant package also available
-
Note 1: Please contact SMSC for the latest value.
ORDERING INFORMATION
Order Numbers:
FDC37B787QFP for 128 pin QFP package
FDC37B787-NS for 128 pin QFP lead-free RoHS compliant package
2
TABLE OF CONTENTS
FEATURES ........................................................................................................................................... 1
GENERAL DESCRIPTION ................................................................................................................. 6
DESCRIPTION OF PIN FUNCTIONS............................................................................................... 7
BUFFER TYPE DESCRIPTIONS .................................................................................................... 11
REFERENCE DOCUMENTS ........................................................................................................... 13
FUNCTIONAL DESCRIPTION......................................................................................................... 14
SUPER I/O REGISTERS ............................................................................................................... 14
HOST PROCESSOR INTERFACE .............................................................................................. 14
FLOPPY DISK CONTROLLER....................................................................................................... 16
FDC INTERNAL REGISTERS ................................................................................................. 16
COMMAND SET/DESCRIPTIONS.......................................................................................... 41
Force Write Protect .................................................................................................................. 70
SERIAL PORT (UART) ..................................................................................................................... 70
REGISTER DESCRIPTION ...................................................................................................... 70
INFRARED INTERFACE .................................................................................................................. 88
PARALLEL PORT ............................................................................................................................. 88
IBM XT/AT COMPATIBLE, BI-DIRECTIONAL AND EPP MODES........................................ 90
EXTENDED CAPABILITIES PARALLEL PORT.......................................................................... 96
PARALLEL PORT FLOPPY DISK CONTROLLER.................................................................. 108
POWER MANAGEMENT................................................................................................................ 110
FDC Power Management ...................................................................................................... 110
UART Power Management ................................................................................................... 115
Parallel Port.............................................................................................................................. 115
VBAT Support ............................................................................................................................ 115
VTR Support .............................................................................................................................. 115
Internal PWRGOOD................................................................................................................ 116
CIRCC PLL Power Control ................................................................................................... 116
32.768 kHz Standby Clock Output...................................................................................... 116
BIOS BUFFER.................................................................................................................................. 121
GENERAL PURPOSE I/O .............................................................................................................. 123
3
Description............................................................................................................................... 123
RUN STATE GPIO DATA REGISTER ACCESS................................................................ 123
GPIO OPERATION .................................................................................................................. 127
8042 KEYBOARD CONTROLLER DESCRIPTION ................................................................... 130
RTC INTERFACE............................................................................................................................. 138
SOFT POWER MANAGEMENT.................................................................................................... 148
ACPI/PME/SMI FEATURES........................................................................................................... 152
ACPI Features.......................................................................................................................... 152
Wake Events ............................................................................................................................. 153
PME SUPPORT........................................................................................................................ 154
ACPI/PME/SMI REGISTERS...................................................................................................... 154
Register Description................................................................................................................. 154
Wakeup Event Configuration is Retained by Battery Power ...................................... 156
Register Block......................................................................................................................... 156
ACPI REGISTERS ................................................................................................................... 157
CONFIGURATION ........................................................................................................................... 168
SYSTEM ELEMENTS .................................................................................................................. 168
Entering the Configuration State........................................................................................ 149
Exiting the Configuration State .......................................................................................... 149
CONFIGURATION SEQUENCE............................................................................................ 149
CONFIGURATION REGISTERS ................................................................................................... 172
Chip Level (Global) Control/Configuration Registers [0x00-0x2F]............................ 176
Logical Device Configuration/Control Registers [0x30-0xFF] .................................... 179
Logical Device Registers...................................................................................................... 179
I/O Base Address Configuration Register........................................................................ 181
Interrupt Select Configuration Register ........................................................................... 183
DMA Channel Select Configuration Register.................................................................. 184
SMSC Defined Logical Device Configuration Registers .............................................. 185
Parallel Port, Logical Device 3 ............................................................................................ 188
Serial Port 1, Logical Device 4 ............................................................................................ 189
Serial Port 2, Logical Device 5 ............................................................................................ 191
RTC, Logical Device 6 ........................................................................................................... 192
KYBD, Logical Device 7 ........................................................................................................ 193
Auxiliary I/O, Logical Device 8 ............................................................................................ 194
ACPI, Logical Device A ......................................................................................................... 212
OPERATIONAL DESCRIPTION ................................................................................................... 218
MAXIMUM GUARANTEED RATINGS ...................................................................................... 218
DC ELECTRICAL CHARACTERISTICS ................................................................................... 218
4
AC TIMING DIAGRAMS .............................................................................................................. 223
CAPACITIVE LOADING ......................................................................................................... 223
IOW Timing Port 92 ................................................................................................................ 224
POWER-UP TIMING................................................................................................................ 225
Button Timing.......................................................................................................................... 226
ROM INTERFACE.................................................................................................................... 227
ISA WRITE ................................................................................................................................ 228
ISA READ.................................................................................................................................. 229
8042 CPU .................................................................................................................................. 231
CLOCK TIMING........................................................................................................................ 232
Burst Transfer DMA Timing ................................................................................................. 235
DISK DRIVE TIMING ............................................................................................................... 237
SERIAL PORT .......................................................................................................................... 238
Parallel Port.............................................................................................................................. 239
EPP 1.9 Data or Address Write Cycle................................................................................ 240
EPP 1.9 Data or Address Read Cycle................................................................................ 242
EPP 1.7 Data Or Address Write Cycle ............................................................................... 244
EPP 1.7 Data or Address Read Cycle................................................................................ 246
ECP PARALLEL PORT TIMING ........................................................................................... 249
Serial Port Infrared Timing................................................................................................... 254
5
GENERAL DESCRIPTION
The FDC37B78x provides features for compliance
with the “Advanced Configuration and Power
Interface Specification” (ACPI).
These features include support of both legacy and
ACPI power management models through the
selection of SMI or SCI. It implements a power
button override event (4 second button hold to turn
off the system) and either edge triggered
interrupts.
The FDC37B78x with advanced Consumer IR
and IrDA v1.0 support 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, on-chip 12 mA AT bus drivers, and
two floppy direct drive support, soft power
management and SMI support and Intelligent
Power Management including PME and
SCI/ACPI 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 on-chip
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
FDC37B78x incorporates sophisticated power
control circuitry (PCC) which includes support for
keyboard, mouse, modem ring, power button
support and consumer infrared wake-up events.
The PCC supports multiple low power down
modes.
The FDC37B78x provides support for the ISA
Plug-and-Play Standard (Version 1.0a) and
provides for the recommended functionality to
support Windows '95, PC97 and PC98. Through
internal configuration registers, each of the
FDC37B78x 's logical device's I/O address, DMA
channel and IRQ channel may be programmed.
There are 480 I/O address location options, 12
IRQ options or Serial IRQ option, and four DMA
channel options for each logical device.
The FDC37B78x Floppy Disk Controller and
separator do not require any external
components and are therefore easy to use,
lower system cost and reduced board area.
FDC is software and register compatible
SMSC's proprietary 82077AA core.
6
data
filter
offer
The
with
nRDATA
nDSKCHG
CLK32OUT
nPOWERON
BUTTON_IN
nPME/SCI/IRQ9
CLOCKI
SA0
SA1
SA2
SA3
SA4
SA5
SA6
SA7
SA8
SA9
SA10
SA11
SA12
SA13
SA14
SA15
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
1
2
3
4
5
6
7
8
9
10
11
12
13
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
VSS
nDIR
nSTEP
nWDATA
nWGATE
nHDSEL
nINDEX
nTRK0
nWRTPRT
nDS1/GP17
DRVDEN0
DRVDEN1/GP52/IRQ8/nSMI
nMTR0
nMTR1/GP16
nDS0
PD7
VSS
SLCT
PE
BUSY
nACK
nERROR
nALF
nSTROBE
RXD1
TXD1
nDSR1
nRTS1/SYSOP
nCTS1
nDTR1
nRI1
nDCD1
nRI2
VCC
nDCD2
RXD2/IRRX
TXD2/IRTX
nDSR2
nRTS2
nCTS2
nDTR2
FDC37B78x
128 Pin QFP
FIGURE 1 - FDC37B78x PIN CONFIGURATION
6
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
IOCHRDY
TC
VCC
DRQ3
nDACK3
DRQ2
nDACK2
DRQ1
nDACK1
DRQ0
nDACK0
RESET_DRV
SD7
SD6
SD5
SD4
VSS
SD3
SD2
SD1
SD0
AEN
nIOW
nIOR
SER_IRQ/IRQ15
PCI_CLK/IRQ14/GP50
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
PD6
PD5
PD4
PD3
PD2
PD1
PD0
nSLCTIN
nINIT
VCC
nROMOE/IRQ12/GP54/EETI
nROMCS/IRQ11/GP53/EETI
RD7/IRQ10/GP67
RD6/IRQ8/GP66
RD5/IRQ7/GP65
RD4/IRQ6/GP64/P17
RD3/IRQ5/GP63/WDT
RD2/IRQ4/GP62/nRING
RD1/IRQ3/GP61/LED
RD0/IRQ1/GP60/nSMI
GP15/IRTX2
GP14/IRRX2
GP13/LED
GP12/WDT/P17/EETI
GP11/nRING/EETI
GP10/nSMI
A20M
KBDRST
VSS
MCLK
MDAT
KCLK
KDAT
VTR
XTAL2
AVSS
XTAL1
VBAT
DESCRIPTION OF PIN FUNCTIONS
PIN
No./QFP
NAME
TOTAL
SYMBOL
BUFFER TYPE
PROCESSOR/HOST INTERFACE (40)
44-47,
System Data Bus
8
SD[0:7]
IO12
16-bit System Address Bus
16
SA[0:15]
I
43
Address Enable
1
AEN
I
64
I/O Channel Ready
1
IOCHRDY
53
ISA Reset Drive
1
RESET_DRV
40
Serial IRQ/IRQ15
1
SER_IRQ
IO12
39
PCI Clock/IRQ14/GP50
1
PCI_CLK
IO12
55
DMA Request 0
1
DRQ0
O12
57
DMA Request 1
1
DRQ1
O12
59
DMA Request 2
1
DRQ2
O12
61
DMA Request 3
1
DRQ3
O12
54
DMA Acknowledge 0
1
nDACK0
I
56
DMA Acknowledge 1
1
nDACK1
I
58
DMA Acknowledge 2
1
nDACK2
I
60
DMA Acknowledge 3
1
nDACK3
I
63
Terminal Count
1
TC
I
41
I/O Read
1
nIOR
I
42
I/O Write
1
nIOW
I
I
49-52
23-38
OD12
IS
CLOCKS (4)
22
14.318MHz Clock Input
1
CLOCKI
66
32.768kHz Crystal Input
1
XTAL1
ICLK
68
32.768kHz Crystal Driver
1
XTAL2
OCLK
18
32.768kHz Clock Out
1
CLK32OUT
3
VCC
POWER PINS (10)
62, 93,
+5V Supply Voltage
121
7
O8
PIN
No./QFP
7, 48,
NAME
TOTAL
SYMBOL
Digital Ground
4
VSS
67
Analog Ground
1
AVSS
69
Trickle Supply Voltage
1
VTR
65
Battery Voltage
1
VBAT
BUFFER TYPE
74, 104
POWER MANAGEMENT (3)
19
Power On
1
nPOWERON
OD24
20
Button In
1
BUTTON_IN
I
21
Power Management Event/SCI/IRQ9
1
nPME
O12
FDD INTERFACE (16)
16
Read Disk Data
1
nRDATA
IS
11
Write Gate
1
nWGATE
O24
10
Write Disk Data
1
nWDATA
O24
12
Head Select
1
nHDSEL
O24
8
Step Direction
1
nDIR
O24
9
Step Pulse
1
nSTEP
O24
17
Disk Change
1
nDSKCHG
5
Drive Select 0
1
nDS0
O24
6
Drive Select 1/GP17
1
nDS1
IO24
3
Motor On 0
1
nMTR0
O24
4
Motor On 1/GP16
1
nMTR1
IO24
15
Write Protected
1
nWRTPRT
IS
14
Track 0
1
nTRKO
IS
13
Index Pulse Input
1
nINDEX
IS
1
Drive Density Select 0
1
DRVDEN0
O24
2
Drive Density Select 1/GP52/IRQ8/nSMI
1
DRVDEN1
IO24
IS
GENERAL PURPOSE I/O (6)
77
General Purpose 10/nSMI
1
GP10
IO12
78
General Purpose 11/nRING/EETI
1
GP11
IO4
8
PIN
No./QFP
NAME
TOTAL
SYMBOL
BUFFER TYPE
79
General Purpose 12/WDT/P17/EETI
1
GP12
IO4
80
General Purpose 13/LED Driver
1
GP13
IO24
81
General Purpose 14/Infrared Rx
1
GP14
IO4
82
General Purpose 15/Infrared Tx (Note 3)
1
GP15
IO24
BIOS INTERFACE (10)
83
ROM Bus 0/IRQ1/GP60/nSMI
1
RD0
IO12
84
ROM Bus 1/IRQ3/GP61/LED
1
RD1
IO24
85
ROM Bus 2/IRQ4/GP62/nRING
1
RD2
IO12
86
ROM Bus 3/IRQ5/GP63/WDT
1
RD3
IO12
87
ROM Bus 4/IRQ6/GP64/P17
1
RD4
IO12
88
ROM Bus 5/IRQ7/GP65
1
RD5
IO12
89
ROM Bus 6/IRQ8/GP66
1
RD6
IO12
90
ROM Bus 7/IRQ10/GP67
1
RD7
IO12
91
nROMCS/IRQ11/GP53/EETI
1
nROMCS
IO12
92
nROMOE/IRQ12/GP54/EETI
1
nROMOE
IO12
SERIAL PORT 1 INTERFACE (8)
112
Receive Serial Data 1
1
RXD1
I
113
Transmit Serial Data 1
1
TXD1
O4
115
Request to Send 1
1
nRTS1/
SYSOP
IO4
116
Clear to Send 1
1
nCTS1
I
117
Data Terminal Ready 1
1
nDTR1
O4
114
Data Set Ready 1
1
nDSR1
I
119
Data Carrier Detect 1
1
nDCD1
I
118
Ring Indicator 1
1
nRI1
I
SERIAL PORT 2 INTERFACE (8)
123
Receive Serial Data 2/Infrared Rx
1
RXD2/IRRX
I
124
Transmit Serial Data 2/Infrared Tx (Note 3)
1
TXD2/IRTX
O24
126
Request to Send 2
1
nRTS2
O4
9
PIN
No./QFP
NAME
TOTAL
SYMBOL
BUFFER TYPE
127
Clear to Send 2
1
nCTS2
I
128
Data Terminal Ready
1
nDTR2
O4
125
Data Set Ready 2
1
nDSR2
I
122
Data Carrier Detect 2
1
nDCD2
I
120
Ring Indicator 2
1
nRI2
I
PARALLEL PORT INTERFACE (17)
96-103
Parallel Port Data Bus
8
PD[0:7]
IOP14
95
Printer Select
1
nSLCTIN
OP14
94
Initiate Output
1
nINIT
OP14
110
Auto Line Feed
1
nALF
OP14
111
Strobe Signal
1
nSTROBE
OP14
107
Busy Signal
1
BUSY
I
108
Acknowledge Handshake
1
nACK
I
106
Paper End
1
PE
I
105
Printer Selected
1
SLCT
I
109
Error at Printer
1
nERROR
I
KEYBOARD/MOUSE INTERFACE (6)
70
Keyboard Data
1
KDAT
IOD16
71
Keyboard Clock
1
KCLK
IOD16
72
Mouse Data
1
MDAT
IOD16
73
Mouse Clock
1
MCLK
IOD16
75
Keyboard Reset
1
KBDRST
(Note 2)
O4
76
Gate A20
1
A20M
O4
Note 1
Note 2
Note 3
The “n” as the first letter of a signal name indicates an “Active Low” signal.
KBDRST is active low.
This pin defaults to an output and low.
10
BUFFER TYPE DESCRIPTIONS
SYMBOL
I
IS
ICLK
OCLK
IO4
O4
O8
IO12
O12
OD12
IOP14
OD14
OP14
IOD16
O24
OD24
IO24
TABLE 1 - BUFFER TYPES
DESCRIPTION
Input, TTL compatible.
Input with Schmitt trigger.
RTC 32.768 kHz crystal input.
RTC 32.768 kHz crystal output.
Input/Output, 4mA sink, 2mA source.
Output, 4mA sink, 2mA source.
Output, 8mA sink, 4mA source.
Input/Output, 12mA sink, 6mA source.
Output, 12mA sink, 6mA source.
Output, Open Drain, 12 mA sink.
Input/Output, 14mA sink, 14mA source. Backdrive Protected.
Output, Open Drain, 14mA sink.
Output, 14mA sink, 14mA source. Backdrive Protected.
Input/Output, Open Drain, 16mA sink
Output, 24mA sink, 12mA source.
Output, Open Drain, 24mA sink.
Input/Output, 24mA sink, 12mA source.
11
nSMI*
PME#/SCI
nPowerOn
Button_In
SOFT
POWER
MANAGEMENT
PME/
ACPI
BIOS
BUFFER
nSMI
nROMOE*
nROMCS*
RD[0:7]*
POWER
MANAGEMENT
DATA BUS
SER_IRQ
PD0-7
MULTI-MODE
PARALLEL
PORT/FDC
MUX
nERROR, nACK
nSTB, nSLCTIN,
nINIT, nALF
SERIAL
IRQ
PCI_CLK
BUSY, SLCT, PE,
GENERAL
PURPOSE
I/O
ADDRESS BUS
nIOR
GP6[0:7]*
TXD1
CONFIGURATION
16C550
COMPATIBLE
SERIAL
PORT 1
REGISTERS
nIOW
GP1[0:7]*
GP5[0,2:4]*
AEN
RXD1
nDSR1, nDCD1, nRI1, nDTR1
nCTS1, nRTS1
CONTROL BUS
SA[0:15]
IRTX
SD[O:7]
IRRX
HOST
WDATA
DRQ[0:3]
16C550
COMPATIBLE
SERIAL
PORT 2 WITH
INFRARED
CPU
WCLOCK
INTERFACE
nDACK[0:3]
SMSC
DIGITAL
DATA
SEPARATOR
WITH WRITE
PRECOM-
PROPRIETARY
TC
82077
COMPATIBLE
VERTICAL
IRQ[1,3-12,14]
FLOPPYDISK
CONTROLLER
RESET_DRV
nDSR2, nDCD2, nRI2, nDTR2
KCLK
KDATA
8042
RCLOCK
RXD2(IRRX)
nCTS2, nRTS2
PENSATION
CORE
TXD2(IRTX)
MCLK
MDATA
P20, P21
P17*
IOCHRDY
RDATA
RTC
XTAL1,2
VBAT
CLK32OUT
nINDEX
DENSEL
nDS0,1
nTRK0
nDIR
nMTR0,1
nSTEP
DRVDEN0
nDSKCHG
nWRPRT
nWGATE
Vcc
Vtr
nHDSEL
CLOCK
GEN
nWDATA
nRDATA
DRVDEN1
Vss
*Multi-Function I/O Pin - Optional
FIGURE 2 - FDC37B78x BLOCK DIAGRAM
12
CLOCKI
(14.318)
GENERAL PURPOSE I/O PINS
PIN NO.
QFP
TABLE 2 - GENERAL PURPOSE I/O PIN FUNCTIONS
DEFAULT
ALT
ALT
ALT
BUFFER
FUNCT
FUNCT 1 FUNCT 2 FUNCT 3
TYPE
INDEX
REGISTE
R
GP1
GP1
GP1
GP1
GP1
GP1
GP1
GP1
GP5
GP5
GP5
GP5
GP6
GP6
GP6
GP6
GP6
GP6
GP6
GP6
GPIO
77
GPIO
nSMI
IO12
GP10
78
GPIO
nRING
EETI1
IO4
GP11
79
GPIO
WDT
P17
EETI1
IO4
GP12
80
GPIO
LED
IO24
GP13
81
GPIO
IRRX2
IO4
GP14
82
GPIO
IRTX2
IO24
GP15
4
nMTR1
GPIO
IO24
GP16
6
nDS1
GPIO
IO24
GP17
IO12
39
PCI_CLK
IRQ14
GPIO
GP50
2
DRVDEN1
GPIO
IRQ8
nSMI
IO24
GP52
IO12
91
nROMCS2
IRQ11
GPIO
EETI1
GP53
2
IO12
92
nROMOE
IRQ12
GPIO
EETI1
GP54
IO12
83
RD02,3
IRQ1
GPIO
nSMI
GP60
IO24
84
RD12,3
IRQ3
GPIO
LED
GP61
IO12
85
RD22,3
IRQ4
GPIO
nRING
GP62
IO12
86
RD32,3
IRQ5
GPIO
WDT
GP63
IO12
87
RD42,3
IRQ6
GPIO
P17
GP64
IO12
88
RD52,3
IRQ7
GPIO
GP65
IO12
89
RD62,3
IRQ8
GPIO
GP66
IO12
90
RD72,3
IRQ10
GPIO
GP67
Note 1 Either Edge Triggered Interrupt Inputs.
Note 2 At power-up, RD0-7, nROMCS and nROMOE function as the XD Bus. To use RD0-7 for alternate
functions, nROMCS must stay high until those pins are finished being programmed.
Note 3 These pins cannot be programmed as open drain pins in their original function.
REFERENCE DOCUMENTS
SMSC Consumer Infrared Communications Controller (CIrCC) V1.X
IEEE 1284 Extended Capabilities Port Protocol and ISA Standard, Rev. 1.14, July 14, 1993.
Hardware Description of the 8042, Intel 8 bit Embedded Controller Handbook.
PCI Bus Power Management Interface Specification, Rev. 1.0, Draft, March 18, 1997.
13
FUNCTIONAL DESCRIPTION
SUPER I/O REGISTERS
HOST PROCESSOR INTERFACE
The address map, shown below in Table 4, shows
the addresses of the different blocks of the Super
I/O immediately after power up.
The base
addresses of the FDC, serial and parallel ports can
be moved via the configuration registers. Some
addresses are used to access more than one
register.
The host processor communicates with the
FDC37B78x through a series of read/write
registers. The port addresses for these registers
are shown in Table 4.
Register access is
accomplished through programmed I/O or DMA
transfers. All registers are 8 bits wide. All host
interface output buffers are capable of sinking a
minimum of 12 mA.
TABLE 3 - SUPER I/O BLOCK ADDRESSES
LOGICAL
ADDRESS
BLOCK NAME
DEVICE
Base+(0-5) and +(7)
Floppy Disk
0
3
Parallel Port
SPP
Base+(0-3)
EPP
Base+(0-7)
ECP
Base+(0-3), +(400-402)
ECP+EPP+SPP
Base+(0-7), +(400-402)
Base+(0-7)
Serial Port Com 1
4
Base1+(0-7)
Serial Port Com 2
5
Base2+(0-7)
70,71, Base, Base+(1)
RTC
6
60, 64
KYBD
7
Base + (0-17h)
ACPI, PME, SMI
A
Base + (0-1)
Configuration
NOTES
IR Support
Consumer IR
Note 1: Refer to the configuration register descriptions for setting the base address.
14
FLOPPY DISK CONTROLLER
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.
FDC INTERNAL REGISTERS
The Floppy Disk Controller contains eight internal
registers that facilitate the interfacing between the
host microprocessor and the disk drive. TABLE 4
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.
TABLE 4 - STATUS, DATA AND CONTROL REGISTERS
(Shown with base addresses of 3F0 and 370)
PRIMARY
SECONDARY
ADDRESS
ADDRESS
R/W
REGISTER
Status Register A (SRA)
R
370
3F0
Status Register B (SRB)
R
371
3F1
Digital Output Register (DOR)
R/W
372
3F2
Tape Drive Register (TSR)
R/W
373
3F3
Main Status Register (MSR)
R
374
3F4
Data Rate Select Register (DSR)
W
374
3F4
Data (FIFO)
R/W
375
3F5
Reserved
376
3F6
Digital Input Register (DIR)
R
377
3F7
Configuration Control Register (CCR)
W
377
3F7
16
STATUS REGISTER A (SRA)
Address 3F0 READ ONLY
This register is read-only and monitors the state of the FINTR pin and several disk 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.
PS/2 Mode
RESET
COND.
7
INT
PENDING
0
6
nDRV2
5
STEP
1
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. (See also Force Write Protect
Function)
BIT 6 nDRV2
Active low status of the DRV2 disk interface input
pin, indicating that a second drive has been
installed. Note: This function is not supported
in this chip. (Always 1, indicating 1 drive)
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
TRK0
3
nHDSEL
2
INDX
1
WP
0
nDIR
N/A
1
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. (See also Force Write Protect
Function)
BIT 6 DMA REQUEST
Active high status of the DRQ output pin.
BIT 2 INDEX
Active high 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 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
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 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.
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
edge of RDATA and is cleared by the read of the
DIR register.
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
The DS2 disk interface is not supported. (Always
1)
BIT 1 nDRIVE SELECT 3
The DS3 disk interface is not supported. (Always
1)
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
BIT 7 nDRV2
Active low status of the DRV2 disk interface input,
this is not supported. (Always 1)
20
DIGITAL OUTPUT REGISTER (DOR)
Address 3F2 READ/WRITE
The DOR controls the drive select and motor enables of the disk interface outputs. It 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.
RESET
COND.
7
MOT
EN3
0
6
MOT
EN2
0
5
MOT
EN1
0
4
MOT
EN0
0
3
DMAEN
0
2
1
0
nRESE DRIVE DRIVE
T
SEL1
SEL0
0
0
0
impedance state. This bit is a logic "0" after a
reset and in these modes.
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".
BIT 0 and 1 DRIVE SELECT
These two bits are binary encoded for the drive
selects, thereby allowing only one drive to be
selected at one time.
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 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 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. This bit being a
logic "0" will disable the nDACK and TC inputs,
and hold the DRQ and FINTR outputs in a high
BIT 6 MOTOR ENABLE 2
The MTR2 disk interface output is not. (Always 0)
BIT 7 MOTOR ENABLE 3
The MTR3 disk interface output is not. (Always 0)
Table 6 - Drive Activation Values
DRIVE
DOR VALUE
0
1CH
1
2DH
21
TAPE DRIVE REGISTER (TDR)
Address 3F3 READ/WRITE
TABLE 7 - TAPE SELECT BITS
TAPE SEL1
(TDR.1)
TAPE SEL0
(TDR.0)
DRIVE
SELECTED
0
0
1
1
0
1
0
1
None
1
2
3
Tape Select bits TDR.[1:0] determine the tape
drive number. TABLE 7 illustrates the Tape Select
Bit encoding. Note that drive 0 is the boot device
and cannot be assigned tape support. The
remaining Tape Drive Register bits TDR.[7:2] are
tristated when read. The TDR is unaffected by a
software reset.
The Tape Drive Register (TDR) is included for
82077 software compatibility and allows the user
to assign tape support to a particular drive during
initialization. Any future references to that drive
automatically invokes tape support. The TDR
22
TABLE 8 - INTERNAL 2 DRIVE DECODE - NORMAL
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
1
0
nBIT 5
nBIT 4
X
X
X
1
X
0
1
0
1
nBIT 5
nBIT 4
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 9 - INTERNAL 2 DRIVE DECODE - DRIVES 0 AND 1 SWAPPED
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
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
23
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.
DB7
DB6
DB5
REG 3F3 Reserved Reserved
DB4
Drive Type ID
Floppy Boot Drive
TABLE 10 - 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
and PS/2 Model 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
RESET
COND.
7
6
S/W
POWER
RESET DOWN
0
0
5
0
0
4
PRECOMP2
0
3
PRECOMP1
0
2
1
0
PREDRATE DRATE
COMP0 SEL1
SEL0
0
1
0
BIT 5 UNDEFINED
Should be written as a logic "0".
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 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 mode after a
software reset or access to the Data Register or
Main Status Register.
BIT 2 through 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.
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.
Note: The DSR is Shadowed in the Floppy Data
Rate Select Shadow Register, LD8:CRC2[7:0].
separator circuits will be turned off. The controller
will come out of manual low power.
25
TABLE 11 - PRECOMPENSATION DELAYS
PRECOMPENSATION
PRECOMP
DELAY (nsec)
432
<2Mbps
2Mbps
111
001
010
011
100
101
110
000
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 14
DRIVE RATE
DRT1
DRT0
TABLE 12 - DATA RATES
DATA RATE
DATA RATE
SEL1
SEL0
MFM
FM
DENSEL
DRATE(1)
1
0
0
0
1
1
1Meg
---
1
1
1
0
0
0
0
500
250
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
1
0
1
500
250
0
0
1
0
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.
26
TABLE 13 - DRVDEN MAPPING
DRVDEN1 (1)
DRVDEN0 (1)
DRIVE TYPE
DRATE0
DENSEL
4/2/1 MB 3.5"
2/1 MB 5.25" FDDS
2/1.6/1 MB 3.5" (3-MODE)
DT1
0
DT0
0
1
0
DRATE0
DRATE1
0
1
DRATE0
nDENSEL
1
1
DRATE1
DRATE0
PS/2
TABLE 14 - 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
27
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 read at any time.
7
RQM
6
5
4
DIO
NON
DMA
CMD
BUSY
3
2
Reserved Reserved
1
0
DRV1
BUSY
DRV0
BUSY
DATA REGISTER (FIFO)
BIT 0 - 1 DRV x BUSY
These bits are set to 1s when a drive is in the seek
portion of a command, including implied and
overlapped seeks and recalibrates.
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.
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.
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 15 gives several examples of the delays
with a FIFO. The data is based upon the following
formula:
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 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.
1
Threshold # x
BIT 7 RQM
Indicates that the host can transfer data if set to a
1. No access is permitted if set to a 0.
DATA RATE
x8
- 1.5 µs = DELAY
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.
An overrun or underrun will terminate the current
command and the transfer of data. Disk writes will
complete
the
current
sector
by
28
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 15 - FIFO SERVICE DELAY
FIFO THRESHOLD
MAXIMUM DELAY TO SERVICING AT
EXAMPLES
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 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
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
or the value programmed in the Force Disk
Change Register (see Configuration Register
LD8:CRC1[1:0]).
BIT 0 - 6 UNDEFINED
The data bus outputs D0 - 6 will remain in a high
impedance state during a read of this register.
30
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
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.
2
1
0
DRATE DRATE nHIGH
SEL1
SEL0 nDENS
N/A
N/A
1
BITS 3 - 6 UNDEFINED
Always read as a logic "1"
BIT 7 DSKCHG
This bit monitors the pin of the same name and
reflects the opposite value seen on the disk cable
or the value programmed in the Force Disk
Change Register (see Configuration Register
LD8:CRC1[1:0]).
BITS 1 - 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
software reset, and are set to 250 Kbps after a
hardware reset.
31
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.
BITS 0 - 1 DATA RATE SELECT
These bits control the data rate of the floppy
controller.
See Table 14 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.
BITS 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 disk cable
or the value programmed in the Force Disk
Change Register (see Configuration Register
LD8:CRC1[1:0]).
BIT 2 NOPREC
This bit reflects the value of NOPREC bit set in the
CCR register.
32
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 0 and 1 DATA RATE SELECT 0 and 1
These bits determine the data rate of the floppy controller. See Table 14 for the appropriate values.
BIT 2 - 7 RESERVED
Should be set to a logical "0"
PS/2 Model 30 Mode
RESET
COND.
7
6
5
4
3
N/A
N/A
N/A
N/A
N/A
2
1
0
NOPREC DRATE DRATE
SEL1
SEL0
N/A
1
0
BIT 3 - 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 14 for the appropriate
values.
Table 15 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.
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.
33
BIT NO.
SYMBOL
TABLE 16 - 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
3
2
1,0
Unused. This bit is always "0".
The current selected drive.
34
BIT NO.
7
SYMBOL
EN
TABLE 17 - 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 Writeable
WP pin became a "1" while the FDC is executing a Write
Data, Write Deleted Data, or Format A Track command.
0
MA
Missing
Address Mark
Any one of the following:
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.
35
BIT NO.
SYMBOL
TABLE 18 - 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
Address Mark
The FDC cannot detect a data address mark or a deleted
data address mark.
36
BIT NO.
SYMBOL
TABLE 19 - 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
HD
Head Address Indicates the status of the HDSEL pin.
DS1,0
Drive Select
3
2
1,0
Indicates the status of the WP pin.
Indicates the status of the TRK0 pin.
Unused. This bit is always "1".
Indicates the status of the DS1, DS0 pins.
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.
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 power down state.
MODES OF OPERATION
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.
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 3 and 2 respectively of LD8CRF0.
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.
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.
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.
DOR Reset vs. DSR Reset (Software Reset)
These two resets are functionally the same.
37
command code bytes and parameter bytes has to
be written to the FDC before the command phase
is complete. (Please refer to TABLE 20 for the
command set descriptions). These bytes of data
must be transferred in the order prescribed.
Model 30 mode - (IDENT low, MFM low)
This mode supports PS/2 Model 30 configuration
and register set. The DMA enable bit of the DOR
becomes valid (FINTR and DRQ can be hi Z), TC
is active high and DENSEL is active low.
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.
DMA TRANSFERS
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.
The FIFO is disabled during the command phase
to provide for the proper handling of the "Invalid
Command" condition.
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.
Two DMA transfer modes are supported 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.
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.
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.
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.
CONTROLLER PHASES
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.
Command Phase
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
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
38
very responsive to the service request. This is the
desired case for use with a "fast" system.
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.
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.
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 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.
Data Transfer Termination
Non-DMA Mode - Transfers from the Host to the
FIFO
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.
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).
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 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 FIFO to the Host
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.
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
Result Phase
39
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.
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.
40
COMMAND SET/DESCRIPTIONS
The user sends a Sense Interrupt Status
command which returns an invalid command error.
Refer to TABLE 20 for explanations of the various
symbols used. TABLE 21 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 interrupt is issued.
SYMBOL
TABLE 20 - DESCRIPTION OF COMMAND SYMBOLS
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
Drive Select 0-1
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
DTL
Special Sector
Size
DS1 DS0 Drive Selected
0
0
Drive 0
0
1
Drive 1
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.
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.
EOT
End of Track
The final sector number of the current track.
GAP
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.
41
SYMBOL
NAME
DESCRIPTION
HLT
Head Load Time
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
MFM
MT
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.
Lock defines whether EFIFO, FIFOTHR, and PRETRK parameters of
the CONFIGURE COMMAND can be reset to their default values by
a "software Reset". (A reset caused by writing to the appropriate bits
of either tha DSR or DOR)
MFM/FM Mode
Selector
A one selects the double density (MFM) mode. A zero selects single
density (FM) mode.
TABLE 21 - DESCRIPTION OF COMMAND SYMBOLS
Multi-Track
When set, this flag selects the multi-track operating mode. In this
Selector
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.
N
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
0
128 Bytes
1
256 Bytes
2
512 Bytes
3
1024 Bytes
…
…
The desired cylinder number.
NCN
New Cylinder
Number
ND
Non-DMA Mode
Flag
When set to 1, indicates that the FDC is to operate in the non-DMA
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 id defined in the Lock command.
PCN
Present Cylinder
Number
The current position of the head at the completion of Sense Interrupt
Status command.
42
POLL
TABLE 21 - DESCRIPTION OF COMMAND SYMBOLS
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.
SC
Number of Sectors The number of sectors per track to be initialized by the Format
Per Track
command. The number of sectors per track to be verified during a
Verify command when EC is set.
SK
Skip Flag
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.
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 Mbit data rate. Refer to the SPECIFY command for actual
delays.
ST0
ST1
ST2
ST3
Status 0
Status 1
Status 2
Status 3
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.
WGATE
Write Gate
Alters timing of WE to allow for pre-erase loads in perpendicular
drives.
43
INSTRUCTION SET
TABLE 22 - 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
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 --------
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
W
MT
MFM
SK
0
1
W
0
0
0
0
0
D1
D0
1
0
0
REMARKS
Command Codes
HDS DS1 DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
D2
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
W
MT
MFM
0
0
0
W
0
0
0
0
0
D1
D0
1
0
1
REMARKS
Command Codes
HDS DS1 DS0
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
D2
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
W
MT
MFM
0
0
1
0
0
1
W
0
0
0
0
0
HDS
DS1
DS0
D2
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
D1
D0
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
W
0
MFM
0
0
0
0
1
0
W
0
0
0
0
0
HDS
DS1
DS0
D2
W
-------- C --------
W
-------- H --------
W
-------- R --------
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------- DTL -------
Execution
Result
D1
D0
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 --------
D1
D0
Command Codes
Sector ID information
prior to Command
execution.
W
-------- N --------
W
------- EOT -------
W
------- GPL -------
W
------ DTL/SC ------
Execution
Result
REMARKS
No data transfer takes
place.
R
------- ST0 -------
R
------- ST1 -------
R
------- ST2 -------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
Status information after
Command execution.
Sector ID information
after Command
execution.
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
W
0
MFM
0
0
1
1
0
1
W
0
0
0
0
0
HDS
DS1
DS0
D2
D1
REMARKS
D0
Command Codes
W
-------- N --------
W
-------- SC --------
Sectors/Cylinder
Bytes/Sector
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
W
0
0
0
0
0
1
1
1
W
0
0
0
0
0
0
DS1
DS0
D1
REMARKS
D0
Execution
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
W
0
W
W
D6
D5
D4
D3
0
0
0
0
--- SRT ---
D2
D1
D0
0
1
1
--- HUT ---
------ HLT ------
51
ND
REMARKS
Command Codes
SENSE DRIVE STATUS
DATA BUS
PHASE
Command
Result
R/W
D7
D6
D5
D4
D3
W
0
0
0
0
0
1
0
0
W
0
0
0
0
0
HDS
DS1
DS0
R
D2
D1
REMARKS
D0
------- ST3 -------
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
0
0
0
0
0
0
0
W
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
W
1
DIR
0
0
1
1
1
1
W
0
0
0
0
0
HDS
DS1
DS0
W
D2
D1
REMARKS
D0
------- 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
D2
EIS EFIFO
POLL
D1
D0
-------- PRETRK --------
53
GAP
WGATE
-- FIFOTHR --
REMARKS
*Note:
Registers
placed in
FIFO
READ ID
DATA BUS
PHASE
Command
R/W
D7
D6
D5
D4
D3
W
0
MFM
0
0
1
0
1
0
W
0
0
0
0
0
HDS
DS1
DS0
D2
Execution
Result
D1
D0
REMARKS
Commands
The first correct ID
information on the
Cylinder is stored in Data
Register
R
-------- ST0 --------
Status information after
Command execution.
Disk status after the
Command has
completed
R
-------- ST1 --------
R
-------- ST2 --------
R
-------- C --------
R
-------- H --------
R
-------- R --------
R
-------- N --------
54
PERPENDICULAR MODE
DATA BUS
PHASE
Command
R/W
W
D7
D6
D5
D4
D3
D2
D1
REMARKS
D0
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
Command
W
----- Invalid Codes -----
Result
R
------- ST0 -------
D1
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
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.
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.
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 "Multi-Sector 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 CRC bytes, and at the end of the
sector, terminate the Read Data Command. N
determines the number of bytes per sector (see
Table 23 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.
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
TABLE 23 - SECTOR SIZES
N
SECTOR SIZE
00
01
02
03
..
07
128 bytes
256 bytes
512 bytes
1024 bytes
...
16 Kbytes
56
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.
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 24.
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.
MT
0
1
0
1
0
1
N
1
1
2
2
3
3
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 the Read Data Command.
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 25
describes the effect of the SK bit on the Read
Data command execution and results. Except
where noted in Table 25, the C or R value of the
sector address is automatically incremented.
TABLE 24 - EFFECTS OF MT AND N BITS
MAXIMUM TRANSFER
FINAL SECTOR READ
CAPACITY
FROM DISK
26 at side 0 or 1
256 x 26 = 6,656
26 at side 1
256 x 52 = 13,312
15 at side 0 or 1
512 x 15 = 7,680
15 at side 1
512 x 30 = 15,360
8 at side 0 or 1
1024 x 8 = 8,192
16 at side 1
1024 x 16 = 16,384
57
SK BIT
VALUE
0
0
1
1
TABLE 25 - SKIP BIT VS READ DATA COMMAND
DATA ADDRESS
MARK TYPE
RESULTS
ENCOUNTERED
SECTOR CM BIT OF DESCRIPTION OF
READ?
ST2 SET?
RESULTS
Normal
No
Yes
Normal Data
termination.
Address not
Yes
Yes
Deleted Data
incremented. Next
sector not
searched for.
Normal
No
Yes
Normal Data
termination.
Normal
Yes
No
Deleted Data
termination. Sector
not read
("skipped").
58
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.
TABLE 26 describes the effect of the SK bit on the
Read Deleted Data command execution and
results.
Except where noted in Table 26, the C or R value
of the sector address is automatically incremented
(see Table 27).
TABLE 26 - SKIP BIT VS. READ DELETED DATA COMMAND
DATA ADDRESS
RESULTS
SK BIT
VALUE
MARK TYPE
ENCOUNTERED
SECTOR
READ?
CM BIT OF
ST2 SET?
DESCRIPTION OF
RESULTS
Address not
incremented. Next
sector not
searched for.
Normal
termination.
Normal
termination. Sector
not read
("skipped").
Normal
termination.
0
Normal Data
Yes
Yes
0
Deleted Data
Yes
No
1
Normal Data
No
Yes
1
Deleted Data
Yes
No
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
command and sets the ND flag of Status Register
59
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".
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.
TABLE 27 - RESULT PHASE TABLE
MT
0
HEAD
0
1
1
0
1
FINAL SECTOR
TRANSFERRED TO
HOST
C
ID INFORMATION AT RESULT PHASE
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.
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.
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 "Multi-Sector
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 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.
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:
60
•
•
•
•
•
•
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
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 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.
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 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
27 and Table 28 for information concerning the
values of MT and EC versus SC and EOT value.
Definitions:
# Sectors Per Side = Number of formatted sectors
per each side of the disk.
# Sectors Remaining = Number of formatted
sectors left which can be read, including side 1 of
the disk if MT is set to "1".
TABLE 28 - VERIFY COMMAND RESULT PHASE
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.
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
61
C, H, R, and N (cylinder, head, sector number and
sector size respectively).
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.
TABLE 29 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 N C GAP2 SYNC
22x
12x
E O R
C
4E
00
C
3x FE
A1
DATA
AM
C
DATA R GAP3 GAP 4b
C
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 N C GAP2 SYNC
E O R
11x
6x
C
C
FF
00
FE
DATA
AM
C
DATA R GAP3 GAP 4b
C
FB or
F8
PERPENDICULAR FORMAT
GAP4a
80x
4E
SYNC
12x
00
IAM
3x FC
C2
GAP1 SYNC
12x
50x
00
4E
IDAM
C
Y
L
H
D
S N C GAP2 SYNC
12x
41x
E O R
00
4E
C
C
3x FE
A1
DATA
AM
3x FB
A1 F8
105
C
DATA R GAP3 GAP 4b
C
TABLE 29 - TYPICAL VALUES FOR FORMATTING
FORMAT SECTOR SIZE
N
SC
GPL1
FM
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
GPL2
128
128
512
1024
2048
4096
...
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.
63
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.
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.
Upon power up, the software must issue a
Recalibrate command to properly initialize all
drives and the controller.
Read ID
Seek
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.
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:
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.
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 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. 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.
Recalibrate
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. 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.
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
Note that if implied seek is not enabled, the read
and write commands should be preceded by:
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.
The Seek command does not have a result phase.
Therefore, it is highly recommended that the
64
Sense Interrupt Status command is 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.
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
Sense Drive Status
An interrupt signal on FINT pin is generated by the
FDC for one of the following reasons:
Sense Drive Status obtains drive status
information. It has not execution phase and goes
directly to the result phase from the command
phase. Status Register 3 contains the drive status
information.
1. Upon entering the Result Phase of:
a. Read Data command
b. Read A Track command
c. Read ID command
d. Read Deleted Data command
e. Write Data command
f. Format A Track command
g. Write Deleted Data command
h. Verify command
2. End of Seek, Relative Seek, or Recalibrate
command
3. FDC requires a data transfer during the
execution phase in the non-DMA mode
Specify
The Specify command sets the initial values for
each of the three internal times. The HUT (Head
Unload Time) defines the time 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 speed selection and are documented in
TABLE 31. The values are the same for MFM
and FM.
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.
TABLE 30 - INTERRUPT IDENTIFICATION
SE
IC
0
1
11
00
1
01
INTERRUPT DUE TO
Polling
Normal termination of Seek
or Recalibrate command
Abnormal termination of
Seek or Recalibrate
command
TABLE 31 - DRIVE CONTROL DELAYS (MS)
HUT
0
1
SRT
2M
1M
500K
300K
250K
2M
1M
500K
300K
250K
64
4
128
8
256
16
426
26.7
512
32
4
3.75
8
7.5
16
15
26.7
25
32
30
65
..
E
F
..
112
120
..
56
60
..
373
400
..
224
240
..
0.5
0.25
..
448
480
..
2
1
..
1
0.5
..
4
2
..
3.33
1.67
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
performed while the drive head is loaded and the
head unload delay has not expired.
The choice of DMA or non-DMA operations is
made by the ND bit. When this bit is "1", the nonDMA mode is selected, and when ND is "0", the
DMA mode is selected. In DMA mode, data
transfers are signaled by the FDRQ pin. Non-DMA
mode uses the RQM bit and the FINT pin to signal
data transfers.
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.
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.
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.
Configure Default Values:
EIS - No Implied Seeks
EFIFO - FIFO Disabled
POLL - Polling Enabled
FIFOTHR - FIFO Threshold Set to 1 Byte
PRETRK - Pre-Compensation Set to Track 0
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.
EFIFO - A "1" disables the FIFO (default). This
means data transfers are asked for on a byte-bybyte basis. Defaults to "1", FIFO disabled. The
threshold defaults to "1".
POLL - Disable polling of the drives. Defaults to
"0", polling enabled. When enabled, a single
interrupt is generated after a reset. No polling is
67
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.
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.
Relative Seek
The command is coded the same as for Seek,
except for the MSB of the first byte and the DIR
bit.
DIR
0
1
ACTION
Step Head Out
Step Head In
DIR
Head Step Direction Control
RCN
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.
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 to keep track of with
software without the Read ID command.
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
with a single Relative Seek command is 255 (D).
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 32
describes the effects of the WGATE and GAP bits
for the Perpendicular Mode command. Upon a
67
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).
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.
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.
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 58 illustrates the change in the Gap2 field
size for the perpendicular format.
The perpendicular mode command is enhanced to
allow specific drives to be designated
Perpendicular recording drives. This 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 pre-compensation values.
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:
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.
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.
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.
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 57. 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
Software and hardware resets have the following
effect on the PERPENDICULAR MODE
COMMAND:
1. "Software" resets (via the DOR or DSR
registers) will only clear GAP and WGATE bits
68
(GAP, WGATE and D0-D3) to "0", i.e all
conventional mode.
to "0". D0-D3 are unaffected and retain their
previous value.
2. "Hardware" resets will clear all bits
WGATE
GAP
0
0
0
1
1
0
1
1
TABLE 32 - EFFECTS OF WGATE AND GAP BITS
PORTION OF GAP 2
LENGTH OF GAP2
WRITTEN BY WRITE DATA
MODE
FORMAT FIELD
OPERATION
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
69
the eighth byte of the DUMPREG command has
been modified to contain the additional data from
these two commands.
LOCK
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.
COMPATIBILITY
This chip was designed with software
compatibility in mind. It is a fully backwardscompatible 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.
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
LOCK command. This byte reflects the value of
the LOCK bit set by the command byte.
Force Write Protect
The Force Write Protect function forces the FDD
nWRTPRT input active if the FORCE WRTPRT
bit is active. The Force Write Protect function
applies to the nWRTPRT pin in the FDD
Interface as well as the nWRTPRT pin in the
Parallel Port FDC.
Refer to Configuration
Register L8CR_C5 for more information.
ENHANCED DUMPREG
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
SERIAL PORT (UART)
disabling, power down and changing the base
address of the UARTs. The interrupt from a
UART is enabled 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 1.0, HP-SIR, ASK-IR and
Consumer IR infrared modes of operation.
The chip incorporates two full function UARTs.
They are compatible with the NS16450, the 16450
ACE registers and the NS16C550A. The UARTS
perform serial-to-parallel 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
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 configuration registers
70
contains two serial ports, each of which contain a
register set as described below.
(see Configuration section) define the base
addresses of the serial ports. The Serial Port
registers are located at sequentially increasing
addresses above these base addresses. The chip
DLAB*
TABLE 33 - ADDRESSING THE SERIAL PORT
A2
A1
A0
REGISTER NAME
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
72
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".
Bit 1
This bit enables the Transmitter Holding Register
Empty Interrupt when set to logic "1".
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.
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.
Bits 4 through 7
These bits are always logic "0".
RECEIVE BUFFER REGISTER (RB)
Address Offset = 0H, DLAB = 0, READ ONLY
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.
TRANSMIT BUFFER REGISTER (TB)
Address Offset = 0H, DLAB = 0, WRITE ONLY
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.
FIFO CONTROL REGISTER (FCR)
Address Offset = 2H, DLAB = X, 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 UART1 and UART2
FCR’s are shadowed in the UART1 FIFO Control
Shadow Register (LD8:CRC3[7:0]) and UART2
FIFO Control Shadow Register (LD8:CRC4[7:0]).
INTERRUPT ENABLE REGISTER (IER)
Address Offset = 1H, DLAB = 0, READ/WRITE
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 chip. 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.
73
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
Writing to this bit has no effect on the operation of
the UART. The RXRDY and TXRDY pins are not
available on this chip.
Bit 4,5
Reserved
Bit 6,7
These bits are used to set the trigger level for the
RCVR FIFO interrupt.
Bit 7
0
Bit 6
0
RCVR FIFO
Trigger Level (BYTES)
1
0
1
4
1
0
8
1
1
14
Transmitter Holding Register Empty
MODEM Status (lowest priority)
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.
Bits 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.
INTERRUPT IDENTIFICATION REGISTER (IIR)
Address Offset = 2H, DLAB = X, READ
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.
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:
Bits 4 and 5
These bits of the IIR are always logic "0".
1.
2.
Bits 6 and 7
These two bits are set when the FIFO CONTROL
Register bit 0 equals 1.
Receiver Line Status (highest priority)
Received Data Ready
74
TABLE 34 - INTERRUPT CONTROL
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
Reading the
No Characters
Receiver Buffer
Have Been
Removed From or Register
Input to the RCVR
FIFO during the
last 4 Char times
and there is at
least 1 char in it
during this time
0
1
0
Third
Transmitter
Transmitter
Holding Register
Holding
Register Empty Empty
0
0
0
Fourth
Reading the
MODEM Status Clear to Send or
Data Set Ready or MODEM Status
Register
Ring Indicator or
Data Carrier
Detect
75
Reading the IIR
Register (if Source
of Interrupt) or
Writing the
Transmitter
Holding Register
LINE CONTROL REGISTER (LCR)
Address Offset = 3H, DLAB = 0, READ/WRITE
BIT 1
0
0
1
1
This register contains the format information of the
serial line. The bit definitions are:
Bits 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:
The Start, Stop and Parity bits are not included in
the word length.
BIT 2
BIT 0
0
1
0
1
WORD LENGTH
5 Bits
6 Bits
7 Bits
8 Bits
Bit 2
This bit specifies the number of stop bits in each
transmitted or received serial character. The
following table summarizes the information. Note:
The receiver will ignore all stop bits beyond the
first, regardless of the number used in transmitting.
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
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 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.
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).
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 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.
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
MODEM CONTROL REGISTER (MCR)
Address Offset = 4H, DLAB = X, READ/WRITE
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.
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".
76
LINE STATUS REGISTER (LSR)
Address Offset = 5H, DLAB = X, READ/WRITE
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 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.
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:
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 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 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.
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 4
1. The TXD is set to the Marking State(logic "1").
2. The receiver Serial Input (RXD) is
disconnected.
3. The output of the Transmitter Shift Register is
"looped back" into the Receiver Shift Register
input.
4. All MODEM Control inputs (nCTS, nDSR, nRI
and nDCD) are disconnected.
5. The four MODEM Control outputs (nDTR,
nRTS, OUT1 and OUT2) are internally
connected to the four MODEM Control inputs
(nDSR, nCTS, RI, DCD).
6. The Modem Control output pins are forced
inactive high.
7. Data that is transmitted is immediately
received.
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.
Bits 5 through 7
These bits are permanently set to logic zero.
77
Address Offset = 6H, DLAB = X, READ/WRITE
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. Restarting after a break is
received, requires the serial data (RXD) to be logic
"1" for at least 1/2 bit time.
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 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.
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 1 byte is
written to the XMIT FIFO. Bit 5 is a read only bit.
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 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.
MODEM STATUS REGISTER (MSR)
78
Address Offset =7H, DLAB =X, READ/WRITE
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 1
Delta Data Set Ready (DDSR). Bit 1 indicates that
the nDSR input has changed state since the last
time the MSR was read.
Bit 2
Trailing Edge of Ring Indicator (TERI). Bit 2
indicates that the nRI input has changed from logic
"0" to logic "1".
Bit 3
Delta Data Carrier Detect (DDCD). Bit 3 indicates
that the nDCD input to the chip has changed state.
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
the remainder of the count. The input clock to the
BRG is a 1.8462 MHz clock.
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.
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.
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.
SCRATCHPAD REGISTER (SCR)
Table 35 shows the baud rates possible with a
1.8462 MHz crystal.
79
Table 35 - Baud Rates Using 1.8462 MHz Clock for <= 38.4K; Using 1.8432MHz Clock
for 115.2k ; Using 3.6864MHz Clock for 230.4k; Using 7.3728 MHz Clock for 460.8k
HIGH
DESIRED
DIVISOR USED TO
PERCENT ERROR DIFFERENCE
1
SPEED BIT2
BAUD RATE
GENERATE 16X CLOCK
BETWEEN DESIRED AND ACTUAL
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
1
Note : The percentage error for all baud rates, except where indicated otherwise, is 0.2%.
Note 2: The High Speed bit is located in the Device Configuration Space.
80
B. Character times are calculated by using the
RCLK input for a clock signal (this makes the
delay proportional to the baudrate).
Effect Of The Reset on Register File
The Reset Function Table (TABLE 36) details the
effect of the Reset input on each of the registers of
the Serial Port.
C. When a timeout interrupt has occurred it is
cleared and the timer reset when the CPU
reads one character from the RCVR FIFO.
FIFO INTERRUPT MODE OPERATION
When the RCVR FIFO and receiver interrupts are
enabled (FCR bit 0 = "1", IER bit 0 = "1"), RCVR
interrupts occur as follows:
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.
A. The receive data available interrupt will be
issued when the FIFO has reached its
programmed trigger level; it is cleared as soon
as the FIFO drops below its programmed
trigger level.
When the XMIT FIFO and transmitter interrupts
are enabled (FCR bit 0 = "1", IER bit 1 = "1"),
XMIT interrupts occur as follows:
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.
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.
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.
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.
When RCVR FIFO and receiver interrupts are
enabled, RCVR FIFO timeout interrupts occur as
follows:
A.
-
-
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.
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
was longer than 4 continuous character times
ago. (If 2 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.
This will cause a maximum character received to
interrupt issued delay of 160 msec at 300 BAUD
with a 12 bit character.
81
FIFO POLLED MODE OPERATION
With FCR bit 0 = "1" resetting IER bits 0, 1, 2 or 3
or all to zero 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. 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:
-
-
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.
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
82
REGISTER/SIGNAL
Interrupt Enable Register
TABLE 36 - RESET FUNCTION
RESET CONTROL
RESET
RESET STATE
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
83
TABLE 37 - REGISTER SUMMARY FOR AN INDIVIDUAL UART CHANNEL
REGISTER
REGISTER
ADDRESS*
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)
ADDR = 3
FCR
(Note 7)
FIFO Enable RCVR FIFO
Reset
Line Control Register
LCR
Word Length Word Length
Select Bit 0 Select Bit 1
(WLS0)
(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.
84
TABLE 38 - 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 2
Data Bit 3
Data Bit 4
Data Bit 5
Data Bit 6
Data Bit 7
Data Bit 7
0
0
0
0
Interrupt ID Bit Interrupt ID Bit 0
(Note 5)
0
FIFOs
Enabled
(Note 5)
FIFOs
Enabled
(Note 5)
Enable
Receiver Line
Status
Interrupt
(ELSI)
Enable
MODEM
Status
Interrupt
(EMSI)
XMIT FIFO
Reset
DMA Mode
Select (Note
6)
Reserved
Reserved
RCVR Trigger
LSB
RCVR Trigger
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
(FE)
Break
Interrupt (BI)
Transmitter
Holding
Register
(THRE)
Error in RCVR
Transmitter
Empty (TEMT) FIFO (Note 5)
(Note 2)
Trailing Edge
Ring Indicator
(TERI)
Delta Data
Carrier Detect
(DDCD)
Clear to Send
(CTS)
Data Set
Ready (DSR)
Ring Indicator
(RI)
Data Carrier
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 10
Bit 11
Bit 12
Bit 13
Bit 14
Bit 15
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
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.
The UART1 and UART2 FCR’s are shadowed in the UART1 FIFO Control Shadow Register
(LD8:CRC3[7:0]) and UART2 FIFO Control Shadow Register (LD8:CRC4[7:0]).
85
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.
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.
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.
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 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 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.
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 higher baud rate capability (256 kbaud).
Ring Wake Filter
An optional filter is provided to prevent glitches to
the wakeup circuitry and prevent unnecessary
wakeup of the system when a phone is picked up
or hung up. If enabled, this filter will be placed
into the soft power management, SMI and
PME/SCI wakeup event path of either of the
UART ring indicator pins (nRI1, nRI2), or the
nRING pin, which is an alternate function on
GP11 and GP62.
This feature is enabled onto the nRING pin or
one of the ring indicator pins (nRI1, nRI2) via the
Ring Filter Select Register defined below. If
enabled, a frequency detection filter is placed in
the path to the soft power management block,
SMI and PME interface that generates an active
Rx support functions and operation are quite
different from those described for the transmitter.
86
<PM1_BLK>+14h). 1=Enable ring indication
on nRING pin as SMI function. 0=Disable.
Note: the PME status bit for RING is used as
the SMI status bit for RING (see PME Status
Register).
3. A status and enable bit is in the PME status
and enable registers as follows:
•
RING Status bit - R/W: RING_STS, Bit 5 of
PME Status Register 1 (System I/O Space,
at <PM1_BLK>+Ch); latched, cleared by
writing a “1” to this bit. 1= Ring indicator
input occurred on the nRING pin and, if
enabled, caused the nPME/SCI or SMI. 0=
nRING input did not occur.
•
RING Enable bit - R/W: RING_EN, Bit 5 of
PME Enable Register 1 (System I/O Space,
at <PM1_BLK>+Eh).
1=Enable ring
indication on nRING pin as PME wakeup
function. 0=Disable.
low pulse for the duration of a signal that
produces 3 edges in a 200msec time period i.e.,
detects a pulse train of frequency 15Hz or higher.
This filter circuit runs off of the 32 Khz clock. This
circuit is powered by the VTR power supply.
When this circuit is disabled, it will draw no
current.
The nRING function is part of the soft power
management block as an additional wakeup
event, and the SMI and PME interface logic.
1. A status and enable bit is in the soft power
status and enable registers as follows:
•
RING Status bit - R/W: RING_STS, Bit 3 of
Soft Power Status Register 2 (Logical
Device 8, 0xB3); latched, cleared on read.
1= Ring indicator input occurred on the
nRING pin and, if enabled, caused the
wakeup (activated nPowerOn). 0= nRING
input did not occur.
•
RING Enable bit - R/W: RING_EN, Bit 3 of
Soft Power Enable Register 2 (Logical
Device 8, 0xB1). 1=Enable ring indication
on nRING pin as wakeup function to activate
nPowerOn. 0=Disable.
2. An enable bit is in the SMI Enable Register 1
as follows:
•
RING Enable bit - R/W: RING_EN, Bit 0 of
SMI Register 1 (System I/O Space, at
Refer to Logical Device 8, 0xC6 for programming
information
The ring wakeup filter will produce an active low
pulse for the period of time that nRING, nRI1
and/or nRI2 is toggling. See figure below.
RING WAKEUP FILTER OUTPUT
n R IN G
R in g W a k e u p F ilte r O u tp u t
87
INFRARED INTERFACE
The Amplitude Shift Keyed IR allows
asynchronous serial communication at baud rates
up to 19.2K Baud. Each word is sent serially
beginning with a zero value start bit. A zero is
signaled by sending a 500KHz waveform for the
duration of the serial bit time. A one is signaled by
sending no transmission during 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. Several IR implementations
have been provided for the second UART in this
chip (logical device 5), IrDA, Consumer Remote
Control, and Amplitude Shift Keyed IR. The IR
transmission can use the standard UART2 TXD2
and RXD2 pins or optional IRTX and IRRX pins.
These can be selected through the configuration
registers.
If the Half-Duplex option is chosen, there is a timeout 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 halfduplex 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 1.0 allows serial communication at baud rates
up to 115.2 kbps. Each word is sent serially
beginning with a zero value start bit. A zero is
signaled by sending a single IR pulse at the
beginning of the serial bit time. A one 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 consumer remote control interface can
decode NEC PPM remote control frames in
hardware as well provide a general-purpose
synchronous
ASK
encoder/decoder
with
programmable carrier frequency and bit rates to
emulate many other popular remote control
encoding formats; including 38 kHz PPM, PWM
and RC-5. Consult the SMSC CIrCC data sheet
for more details.
PARALLEL PORT
This chip 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.
damage to the parallel port due to printer powerup.
This chip also provides a mode for support of the
floppy disk controller on the parallel port.
The parallel port also incorporates SMSC's
ChiProtect circuitry, which prevents possible
DATA PORT
STATUS PORT
CONTROL PORT
EPP ADDR PORT
EPP DATA PORT 0
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:
88
BASE ADDRESS + 00H
BASE ADDRESS + 01H
BASE ADDRESS + 02H
BASE ADDRESS + 03H
BASE ADDRESS + 04H
EPP DATA PORT 1
EPP DATA PORT 2
EPP DATA PORT 3
BASE ADDRESS + 05H
BASE ADDRESS + 06H
BASE ADDRESS + 07H
The bit map of these registers is:
D0
D1
D2
D3
D4
D5
D6
D7
Note
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
1
STATUS PORT
TMOUT
0
0
nERR
SLCT
PE
nACK
nBUSY
1
CONTROL
PORT
STROBE
AUTOFD
nINIT
SLC
IRQE
PCD
0
0
1
EPP ADDR
PORT
PD0
PD1
PD2
PD3
PD4
PD5
PD6
AD7
2,3
EPP DATA
PORT 0
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
2,3
EPP DATA
PORT 1
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
2,3
EPP DATA
PORT 2
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
2,3
EPP DATA
PORT 3
PD0
PD1
PD2
PD3
PD4
PD5
PD6
PD7
2,3
DATA PORT
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.
75
TABLE 39 - 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.
89
IBM XT/AT COMPATIBLE, BI-DIRECTIONAL AND EPP MODES
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.
DATA PORT
ADDRESS OFFSET = 00H
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.
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.
STATUS PORT
ADDRESS OFFSET = 01H
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 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 0 TMOUT - TIME OUT
This bit is valid in EPP mode only and indicates
that a 10 usec time out has occurred on the EPP
bus. A logic O means that no time out error has
occurred; a logic 1 means that a time out error has
been detected. This bit is cleared by a RESET.
Writing a one 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 zero. Writing a zero to this bit
has no effect.
CONTROL PORT
ADDRESS OFFSET = 02H
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.
BITS 1, 2 - are not implemented as register bits,
during a read of the Printer Status Register these
bits are a low level.
BIT 0 STROBE - STROBE
This bit is inverted and output onto the nSTROBE
output.
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.
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.
90
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 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.
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 bi-directional,
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).
EPP DATA PORT 1
ADDRESS OFFSET = 05H
Bits 6 and 7 during a read are a low level, and
cannot be written.
EPP DATA PORT 2
ADDRESS OFFSET = 06H
EPP ADDRESS PORT
ADDRESS OFFSET = 03H
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.
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.
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.
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 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.
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
91
1.
The host selects an EPP register, places data
on the SData bus and drives nIOW 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 places address or data on PData
bus, clears PDIR, and asserts nWRITE.
5. Chip asserts nDATASTB or nADDRSTRB
indicating that PData bus contains valid
information, and the WRITE signal is valid.
6. Peripheral deasserts nWAIT, indicating that
any setup requirements have been satisfied
and the chip may begin the termination phase
of the cycle.
7. 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.
8. Peripheral asserts nWAIT, indicating to the
host that any hold time requirements have
been satisfied and acknowledging the
termination of the cycle.
9. Chip may modify nWRITE and nPDATA in
preparation for the next cycle.
EPP 1.9 Read
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 10usec have elapsed
from the start of the EPP cycle (nIOR or nIOW
asserted) to nWAIT being 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.
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
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 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:
1.
2.
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:
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.
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
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
92
cycle is aborted and the time-out condition is
indicated in Status bit 0.
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.
Software Constraints
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.
EPP 1.7 Write
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.
Write Sequence of Operation
1.
2.
3.
EPP 1.7 OPERATION
4.
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.
5.
6.
7.
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 10usec 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
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.
EPP 1.7 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.
93
4.
Read Sequence of Operation
1.
2.
3.
5.
6.
The host sets PDIR bit in the control register
to a logic "1". This deasserts nWRITE and tristates 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.
7.
8.
9.
94
If nWAIT is asserted, IOCHRDY is
deasserted until the peripheral deasserts
nWAIT or a time-out occurs.
The Peripheral drives PData bus valid.
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.
Peripheral tri-states the PData bus.
Chip may modify nWRITE, PDIR and
nPDATA in preparation of the next cycle.
TABLE 40 - 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. It is used to denote data read or 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.
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 address read or
Note 1: SPP and EPP can use 1 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.
95
EXTENDED CAPABILITIES PARALLEL PORT
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.
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.
96
The bit map of the Extended Parallel Port registers is:
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
cnfgA
0
0
cnfgB
compress
intrValue
ecr
MODE
Note
2
Parallel Port Data FIFO
2
ECP Data FIFO
2
Test FIFO
2
0
1
0
Parallel Port IRQ
nErrIntrEn
0
0
0
Parallel Port DMA
dmaEn
serviceIntr
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.
supports DMA for ECP in both the forward and
reverse directions.
ISA IMPLEMENTATION STANDARD
This specification describes the standard ISA
interface to the Extended Capabilities Port (ECP).
All ISA devices supporting ECP must meet the
requirements contained in this section or the port
will not be supported by Microsoft. For a
description of the ECP Protocol, please refer to the
IEEE 1284 Extended Capabilities Port Protocol
and ISA Interface Standard, Rev. 1.14, July 14,
1993. This document is available from Microsoft.
Small FIFOs are employed in both forward and
reverse directions to smooth data flow and
improve the maximum bandwidth requirement.
The size of the FIFO is 16 bytes deep. The port
supports an automatic handshake for the standard
parallel port to improve compatibility mode transfer
speed.
The port also supports run length encoded (RLE)
decompression
(required)
in
hardware.
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. Hardware support for
compression is optional.
Description
The port is software and hardware compatible with
existing parallel ports so that it may be used as a
standard LPT port if ECP is not required. The port
is designed to be simple and requires a small
number of gates to implement. It does not do any
"protocol" negotiation, rather it provides an
automatic high burst-bandwidth channel that
97
NAME
TYPE
TABLE 41 - 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.
98
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 to avoid conflict with standard ISA
TABLE 42 - ECP REGISTER DEFINITIONS
ADDRESS (Note 1)
ECP MODES
NAME
data
+000h R/W
000-001
ecpAFifo
+000h R/W
011
FUNCTION
Data Register
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 43 - MODE DESCRIPTIONS
DESCRIPTION*
MODE
000
SPP mode
001
PS/2 Parallel Port mode
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
99
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.
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.
DATA and ecpAFifo PORT
ADDRESS OFFSET = 00H
Modes 000 and 001 (Data Port)
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.
DEVICE CONTROL REGISTER (dcr)
ADDRESS OFFSET = 02H
Mode 011 (ECP FIFO - Address/RLE)
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.
BIT 0 STROBE - STROBE
This bit is inverted and output onto the nSTROBE
output.
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 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.
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.
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 STATUS REGISTER (dsr)
ADDRESS OFFSET = 01H
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 3 nFault
The level on the nFault input is read by the CPU
as bit 3 of the Device Status Register.
BIT 4 Select
The level on the Select input is read by the CPU
as bit 4 of the Device Status Register.
100
tFIFO. If an attempt is made to read data from an
empty tFIFO, the last data byte is re-read 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.
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).
BITS 6 and 7 during a read are a low level, and
cannot be written.
The FIFO size and interrupt threshold can be
determined by writing bytes to the FIFO and
checking the full and serviceIntr bits.
cFifo (Parallel Port Data FIFO)
ADDRESS OFFSET = 400h
Mode = 010
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 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 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.
ecpDFifo (ECP Data FIFO)
ADDRESS OFFSET = 400H
Mode = 011
Data bytes are always read from the head of tFIFO
regardless of the value of the direction bit. For
example if 44h, 33h, 22h is written to the FIFO,
then reading the tFIFO will return 44h, 33h, 22h in
the same order as was written.
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.
cnfgA (Configuration Register A)
ADDRESS OFFSET = 400H
Mode = 111
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.
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)
cnfgB (Configuration Register B)
ADDRESS OFFSET = 401H
Mode = 111
tFifo (Test FIFO Mode)
ADDRESS OFFSET = 400H
Mode = 110
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 6 intrValue
Returns the value on the ISA IRq line to determine
possible conflicts.
BITS [5:3] Parallel Port IRQ (read-only)
Refer to Table 44B.
Data bytes may be read, written or DMAed to or
from the system to this FIFO in any direction.
Data in the tFIFO will not be transmitted to the 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
101
1:
Disables DMA and all of the service
interrupts.
0: Enables one of the following 3 cases of
interrupts. Once one of the 3 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 1 full
Read only
1: The FIFO cannot accept another byte or the
FIFO is completely full.
0: The FIFO has at least 1 free byte.
BIT 0 empty
Read only
1: The FIFO is completely empty.
0: The FIFO contains at least 1 byte of data.
BITS [2:0] Parallel Port DMA (read-only)
Refer to Table 44C.
ecr (Extended Control Register)
ADDRESS OFFSET = 402H
Mode = all
This register controls the extended ECP parallel
port functions.
BITS 7,6,5
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.
BIT 3 dmaEn
Read/Write
1: Enables DMA (DMA starts when serviceIntr is
0).
0: Disables DMA unconditionally.
BIT 2 serviceIntr
Read/Write
102
TABLE 44 - 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 44B
TABLE 44C
IRQ SELECTED
15
CONFIG REG B
BITS 5:3
110
DMA SELECTED
3
CONFIG REG B
BITS 2:0
011
14
101
2
010
11
100
1
001
10
011
All Others
000
9
010
7
001
5
111
All Others
000
103
•
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).
ECP address/RLE bytes or data bytes may be
sent automatically by writing the ecpAFifo or
ecpDFifo respectively.
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.
Setting the mode to 011 or 010 will cause the
hardware to initiate data transfer.
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.
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.
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.
After negotiation, it is necessary to initialize some
of the port bits. The following are required:
•
•
Set autoFd = 0, causing the nAutoFd signal
to default to the deasserted state.
Set mode = 011 (ECP Mode)
Set Direction = 0, enabling the drivers.
Set strobe = 0, causing the nStrobe signal to
default to the deasserted state.
104
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.
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.
When in the forward direction, normal data is
transferred when HostAck is high and an 8 bit
command is transferred when HostAck is low.
Pin Definition
The drivers for nStrobe, nAutoFd, nInit and
nSelectIn are open-collector in mode 000 and are
push-pull in all other modes.
The most significant bit of the command indicates
whether it is a run-length count (for compression)
or a channel address.
ISA Connections
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.
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.
Table 45 –
Forward Channel Commands (HostAck Low)
Reverse Channel Commands (PeripAck Low)
D7
D[6:0]
0
Run-Length Count (0-127)
0011 0X00 only)
1
Channel Address (0-127)
(mode
Interrupts
The interrupts are enabled by serviceIntr in the ecr
register.
Data Compression
serviceIntr = 1 Disables the DMA and all of the
service interrupts.
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 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.
serviceIntr = 0
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
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.
The interrupt generated is ISA friendly in that it
must pulse the interrupt line low, allowing for
105
FIFOTHR, which the user programs, is one less
and ranges from 0 to 15.
interrupt sharing. After a brief pulse low following
the interrupt event, the interrupt line is tri-stated so
that other interrupts may assert.
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.
An interrupt is generated when:
1. For DMA transfers: When serviceIntr is 0,
dmaEn is 1 and the DMA TC is received.
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
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.
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.)
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.
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.
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.
The following paragraphs detail the operation of
the FIFO flow control. In these descriptions,
<threshold> ranges from 1 to 16. The parameter
106
DMA Mode - Transfers from the FIFO to the
Host
Programmed I/O - Transfers from the FIFO to
the Host
(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.)
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.
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).
readIntrThreshold =(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 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.
Programmed I/O - Transfers from the Host to
the FIFO
Programmed I/O Mode or Non-DMA Mode
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.
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.
writeIntrThreshold =
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.
Note: A threshold of 16 is equivalent to a threshold
of 15. These two cases are treated the same.
107
(16-<threshold>) free
bytes in 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.
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.
PARALLEL PORT FLOPPY DISK CONTROLLER
The Floppy Disk Control signals are available
optionally 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.
1.
3.
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
The following FDC pins are all in the high
impedence state when the PPFDC is actually
selected by the drive select register:
When the PPFDC is selected the following pins
are set as follows:
1.
nWDATA, DENSEL, nHDSEL, nWGATE,
nDIR, nSTEP, nDS1, nDS0, nMTR0, nMTR1.
1.
2.
2.
If PPFDx is selected, then the parallel port
can not be used as a parallel port until
"Normal" mode is selected.
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.
The FDC signals are muxed onto the Parallel Port
pins as shown in TABLE 47.
Note: nPDACK, PDRQ and PINTR refer to the
nDACK, DRQ and IRQ chosen for the parallel
port.
For ACPI compliance the FDD pins that are
multiplexed onto the Parallel Port function
independently of the state of the Parallel Port
controller. For example, if the FDC is enabled
onto the Parallel Port the multiplexed FDD
interface functions normally regardless of the
Parallel Port Power control, CR22.3. TABLE 46
illustrates this functionality.
The following parallel port pins are read as follows
by a read of the parallel port register:
1.
Data Register (read) = last Data Register
(write)
PARALLEL
PORT
POWER
CR22.3
1
0
X
TABLE 46 - PARALLEL PORT FDD CONTROL
PARALLEL PORT FDC
PARALLEL PORT
CONTROL
FDC STATE
LD3:CRF1.1
0
0
1
X
LD3:CRF1.0
0
0
X
1
108
OFF
OFF
ON
PARALLEL PORT
STATE
ON
OFF
OFF
(NOTE1)
NOTE1: The Parallel Port Control register reads as “Cable Not Connected” when the Parallel Port FDC
is enabled; i.e., STROBE = AUTOFD = SLC = 0 and nINIT = 1.
TABLE 47 - FDC PARALLEL PORT PINS
SPP MODE
nSTROBE
PIN DIRECTION
I/O
FDC MODE
(nDS0)
PIN DIRECTION
I/(O) Note1
PD0
I/O
nINDEX
I
PD1
I/O
nTRK0
I
PD2
I/O
nWP
I
PD3
I/O
nRDATA
I
PD4
I/O
nDSKCHG
I
PD5
I/O
-
-
PD6
I/O
(nMTR0)
PD7
I/O
-
-
nACK
I
nDS1
O
BUSY
I
nMTR1
O
I/(O) Note1
PE
I
nWDATA
O
SLCT
I
nWGATE
O
nALF
I/O
DRVDEN0
O
nERROR
I
nHDSEL
O
nINIT
I/O
nDIR
O
nSLCTIN
I/O
nSTEP
O
Note 1: These pins are outputs in mode PPFD2, inputs in mode PPFD1.
Refer to Force Write Protect in the Floppy Disk Controller section for information on the Floppy disk
Controller Force Write Protect function.
POWER MANAGEMENT
Auto Power Management is enabled by CR23-B0.
When set, this bit allows FDC to enter powerdown
when all of the following conditions have been met:
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.
1.
The motor enable pins of register 3F2H are
inactive (zero).
2.
The part must be idle; MSR=80H and INT = 0
(INT may be high even if MSR = 80H due to
polling interrupts).
3.
The head unload timer must have expired.
FDC Power Management
Direct power management is controlled by CR22.
Refer to CR22 for more information.
110
4.
The Auto powerdown timer (10msec) must
have timed out.
Register Behavior
TABLE 48 illustrates the AT and PS/2 (including
Model 30) configuration registers available and the
type of access permitted. In order to maintain
software transparency, access to all the registers
must be maintained. As TABLE 48 shows, two
sets of registers are distinguished based on
whether their access results in the part remaining
in powerdown state or exiting it.
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.
Disabling the auto powerdown mode cancels the
timer and holds the FDC block out of auto
powerdown.
DSR From Powerdown
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.
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.
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.
Pin Behavior
This chip is specifically designed for systems in
which power conservation is a primary concern.
This makes the behavior of the pins during
powerdown very important.
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:
1.
Enabling any one of the motor enable bits in
the DOR register (reading the DOR does not
awaken the part).
2.
A read from the MSR register.
3.
A read or write to the Data register.
The pins 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.
System Interface Pins
TABLE 49 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 chip when they have
indeterminate input values.
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.
112
TABLE 48 - 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 49 - STATE OF SYSTEM PINS IN AUTO POWERDOWN
SYSTEM PINS
STATE IN AUTO POWERDOWN
INPUT PINS
nIOR
Unchanged
nIOW
Unchanged
SA[0:9]
Unchanged
SD[0:7]
Unchanged
RESET_DRV
Unchanged
DACKx
Unchanged
TC
Unchanged
OUTPUT PINS
IRQx
Unchanged (low)
SD[0:7]
Unchanged
DRQx
Unchanged (low)
113
FDD Interface Pins
Pins used for local logic control or part
programming are unaffected. TABLE 50 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 50 - STATE OF FLOPPY DISK DRIVE INTERFACE PINS IN POWERDOWN
FDD PINS
STATE IN AUTO POWERDOWN
INPUT PINS
nRDATA
Input
nWPROT
Input
nTR0
Input
nINDEX
Input
nDSKCHG
Input
OUTPUT PINS
nMTR0
Tristated
nDS0
Tristated
nDIR
Active
nSTEP
Active
nWDATA
Tristated
nWGATE
Tristated
nHDSEL
Active
DRVDEN[0:1]
Active
115
UART Power Management
1.
ECP is not enabled in the configuration
registers.
Direct power management is controlled by CR22.
Refer to CR22 for more information.
2
SPP, PS/2 Parallel port or EPP mode is
selected through ecr while in ECP mode.
Auto Power Management is enabled by CR23-B4
and B5. When set, these bits allow the following
auto power management operations:
1.
The transmitter enters auto powerdown when
the transmit buffer and shift register are
empty.
2.
The receiver enters powerdown when the
following conditions are all met:
A.
B.
Note:
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.
VBAT Support
This chip requires a (TBD) MicroAmp battery
supply (VBAT) to provide battery backed up
registers. These registers retain the contents of
the general purpose registers and wake-up event
registers. The RTC and CMOS registers are
also battery backed up. Note: The configuration
of the Consumer IR wake-up functionality is not
battery backed-up.
Receive FIFO is empty
The receiver is waiting for a start bit.
While in powerdown the Ring Indicator
interrupt is still valid and transitions when
the RI input changes.
Exit Auto Powerdown
VTR Support
The transmitter exits powerdown on a write to the
XMIT buffer. The receiver exits auto powerdown
when RXDx changes state.
The FDC37B78x requires a 25 mA trickle supply
(VTR) to provide sleep current for the
programmable wake-up events in the Soft Power
Management logic, SCI, PME and SMI interfaces
when VCC is removed. If the FDC37B78x is not
intended to provide wake-up capabilities on
standby current, VTR can be connected to VCC.
VTR powers the Consumer IR receiver, IR
interface, the CIR run-time registers, the PME
configuration registers, and the PME interface.
The VTR pin generates a VTR Power-on-Reset
signal to initialize certain components.
All
wakeup event registers and related logic are
battery backed-up to retain the configuration of
the wakeup events upon a power loss (i.e., VCC =
0 V and VTR = 0 V). These registers are reset on
a VBAT POR.
Parallel Port
Direct power management is controlled by CR22.
Refer to CR22 for more information.
Auto Power Management is enabled by CR23-B3.
When set, this bit allows the ECP or EPP logical
parallel port blocks to be placed into powerdown
when not being used.
The EPP logic is in powerdown under any of the
following conditions:
1.
EPP is not enabled in the configuration
registers.
2.
EPP is not selected through ecr while in ECP
mode.
The ECP logic is in powerdown under any of the
following conditions:
115
Internal PWRGOOD
Note: If VTR is to be used for programmable
wake-up events when VCC is removed, VTR must
be at its full minimum potential at least 10 μs
before Vcc begins a power-on cycle. When VTR
and Vcc are fully powered, the potential difference
between the two supplies must not exceed
500mV.
An internal PWRGOOD logical control is included
to minimize the effects of pin-state uncertainty in
the host interface as Vcc cycles on and off.
When the internal PWRGOOD signal is “1”
(active), Vcc is > 4V, and the FDC37B78x host
interface is active.
When the internal
PWRGOOD signal is “0” (inactive), Vcc is ≤ 4V,
and the FDC37B78x host interface is inactive;
that is, ISA bus reads and writes will not be
decoded.
CIRCC PLL Power Control
The FDC37B78x uses the 32.768 kHz RTC clock
and a clock multiplier (PLL) to drive the CIrCC
Wakeup function when Vcc has been removed.
The CIR PLL Power bit, located in the
Sleep/Wake Configuration Register, is used to
enable (power-up) the 32.768 kHz clock PLL.
When the CIR PLL Power bit is set to “1”
(active), the 32.768 kHz clock PLL is running and
can replace the 14.318 MHz clock source for the
CIR Wake Event, depending upon the state of
the internal PWRGOOD signal (TABLE 51).
When the CIR PLL Power bit is reset to “0”
(inactive/default), the 32.768 kHz clock PLL is
unpowered.
The FDC37B78x device pins nPME, KCLK,
MCLK, IRRX, nRI1, nRI2, RXD1, RXD2, nRING,
Button_In and GP53 are part of the PME
interface and remain active when the internal
PWRGOOD signal has gone inactive, provided
VTR is powered. In addition, the nPowerOn and
CLK32OUT pins remain active when the internal
PWRGOOD is inactive and VTR is powered.
When the internal PWRGOOD is inactive, and
VTR is powered, the GPIOs (excluding GP53)
become tri-state (input) and are able to generate
wake-up events. The internal PWRGOOD signal
is also used to determine the clock source for the
CIrCC CIR and to disable the IR Half Duplex
Timeout.
PLL CONTROL
BIT (CR24.1)
1
0
0
0
0
TABLE 51 - FDC37B78x PLL CONTROLS AND SELECTS
CIR PLL
INTERNAL
POWER BIT
PWRGOOD
DESCRIPTION
X
X
All PLLs Powered Down
0
0
0
1
32KHz PLL Unpowered, Not Selected,
14MHz PLL Powered, Selected.
1
0
32KHz PLL Powered, Selected,
14MHz PLL Unpowered, Not Selected.
1
1
32KHz PLL Powered, Not Selected, 14MHz PLL
Powered, Selected.
32.768 kHz Standby Clock Output
The FDC37B78x provides a 32.768 kHz trickle clock output pin. This output is active as long as VTR is
present.
SERIAL INTERRUPTS
The FDC37B78x will support the serial interrupt to transmit interrupt information to the host system. The
serial interrupt scheme adheres to the Serial IRQ Specification for PCI Systems, Version 6.0.
116
Timing Diagrams For IRQSER Cycle
PCICLK = 33Mhz_IN pin
IRQSER = SIRQ pin
A) Start Frame timing with source sampled a low pulse on IRQ1
START FRAME
SL
or
H
H
R
IRQ0 FRAME IRQ1 FRAME IRQ2 FRAME
T
S
R
T
S
R
T
S
R
PCICLK
START1
IRQSER
Drive Source
IRQ1
None
Host Controller
H=Host Control
SL=Slave Control
S=Sample
R=Recovery
T=Turn-around
1) Start Frame pulse can be 4-8 clocks wide.
118
IRQ1
None
T
B) Stop Frame Timing with Host using 17 IRQSER sampling period
IRQ14
FRAME
S R T
IRQ15
FRAME
S R T
IOCHCK#
FRAME
S R T
STOP FRAME
I
2
H
R
NEXT CYCLE
T
PCICLK
STOP1
IRQSER
Driver
None
IRQ15
None
Host Controller
H=Host Control
R=Recovery
I= Idle.
1)
2)
3)
START3
T=Turn-around
S=Sample
Stop pulse is 2 clocks wide for Quiet mode, 3 clocks wide for Continuous mode.
There may be none, one or more Idle states during the Stop Frame.
The next IRQSER cycle’s Start Frame pulse may or may not start immediately
after the turn-around clock of the Stop Frame.
Any IRQSER Device (i.e., The FDC37B78x)
which detects any transition on an IRQ/Data line
for which it is responsible must initiate a Start
Frame in order to update the Host Controller
unless the IRQSER is already in an IRQSER
Cycle and the IRQ/Data transition can be
delivered in that IRQSER Cycle.
IRQSER Cycle Control
There are two modes of operation for the
IRQSER Start Frame.
1) Quiet (Active) Mode: Any device may initiate
a Start Frame by driving the IRQSER low for one
clock, while the IRQSER is Idle. After driving low
for one clock the IRQSER must immediately be
tri-stated without at any time driving high. A Start
Frame may not be initiated while the IRQSER is
Active. The IRQSER is Idle between Stop and
Start Frames. The IRQSER is Active between
Start and Stop Frames. This mode of operation
allows the IRQSER to be Idle when there are no
IRQ/Data transitions which should be most of the
time.
2) Continuous (Idle) Mode: Only the Host
controller can initiate a Start Frame to update
IRQ/Data line information. All other IRQSER
agents become passive and may not initiate a
Start Frame. IRQSER will be driven low for four
to eight clocks by Host Controller. This mode
has two functions. It can be used to stop or idle
the IRQSER or the Host Controller can operate
IRQSER in a continuous mode by initiating a
Start Frame at the end of every Stop Frame.
Once a Start Frame has been initiated the Host
Controller will take over driving the IRQSER low
in the next clock and will continue driving the
IRQSER low for a programmable period of three
to seven clocks. This makes a total low pulse
width of four to eight clocks. Finally, the Host
Controller will drive the IRQSER back high for
one clock, then tri-state.
An IRQSER mode transition can only occur
during the Stop Frame. Upon reset, IRQSER
bus is defaulted to Continuous mode,
therefore only the Host controller can initiate
the first Start Frame.
Slaves must
continuously sample the Stop Frames pulse
width to determine the next IRQSER Cycle’s
mode.
119
During the Turn-around Phase the FDC37B78x
must tri-state the SERIRQ. The FDC37B78x will
drive the IRQSER line low at the appropriate
sample point if its associated IRQ/Data line is
low, regardless of which device initiated the Start
Frame.
IRQSER Data Frame
Once a Start Frame has been initiated, the
FDC37B78x will watch for the rising edge of the
Start Pulse and start counting IRQ/Data Frames
from there. Each IRQ/Data Frame is three
clocks: Sample phase, Recovery phase, and
Turn-around phase. During the Sample phase
the FDC37B78x must drive the IRQSER (SIRQ
pin) low, if and only if, its last detected IRQ/Data
value was low. If its detected IRQ/Data value is
high, IRQSER must be left tri-stated. During the
Recovery phase the FDC37B78x must drive the
SERIRQ high, if and only if, it had driven the
IRQSER low during the previous Sample Phase.
The Sample Phase for each IRQ/Data follows the
low to high transition of the Start Frame pulse by
a number of clocks equal to the IRQ/Data Frame
times three, minus one. (e.g. The IRQ5 Sample
clock is the sixth IRQ/Data Frame, (6 x 3) - 1 =
17th clock after the rising edge of the Start
Pulse).
119
IRQSER PERIOD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
IRQSER Sampling Periods
SIGNAL SAMPLED
Not Used
IRQ1
nSMI/IRQ2
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
IRQ8
IRQ9
IRQ10
IRQ11
IRQ12
IRQ13
IRQ14
IRQ15
Note:
# OF CLOCKS PAST START
2
5
8
11
14
17
20
23
26
29
32
35
38
41
44
47
It is the responsibility of the software to ensure that two IRQ’s are not set to the same IRQ
number.
IRQSER Period 14 is used to transfer IRQ13.
Logical devices 0 (FDC), 3 (Par Port), 4 (Ser Port
The SIRQ data frame will now support IRQ2 from
1), 5 (Ser Port 2), 6 (RTC), and 7 (KBD) shall
a logical device, previously IRQSER Period 3
have IRQ13 as a choice for their primary
was reserved for use by the System
interrupt.
Management Interrupt (nSMI).
When using
Period 3 for IRQ2 the user should mask off the
SMI via the SMI Enable Register. Likewise,
Note: When Serial IRQs are used, the RTC
when using Period 3 for nSMI the user should
IRQ, nSCI and nSMI may be output on one of
not configure any logical devices as using IRQ2.
their respective pin options. See the IRQ
MUX Configuration Register.
120
followed. This could cause a system fault. The
host interrupt controller is responsible for
ensuring that these latency issues are mitigated.
The recommended solution is to delay EOIs and
ISR Reads to the interrupt controller by the same
amount as the IRQSER Cycle latency in order to
ensure that these events do not occur out of
order.
Stop Cycle Control
Once all IRQ/Data Frames have completed the
Host Controller will terminate IRQSER activity by
initiating a Stop Frame. Only the Host Controller
can initiate the Stop Frame. A Stop Frame is
indicated when the IRQSER is low for two or
three clocks. If the Stop Frame’s low time is two
clocks then the next IRQSER Cycle’s sampled
mode is the Quiet mode; and any IRQSER
device may initiate a Start Frame in the second
clock or more after the rising edge of the Stop
Frame’s pulse. If the Stop Frame’s low time is
three clocks then the next IRQSER Cycle’s
sampled mode is the Continuos mode; and only
the Host Controller may initiate a Start Frame in
the second clock or more after the rising edge of
the Stop Frame’s pulse.
AC/DC Specification Issue
All IRQSER agents must drive / sample IRQSER
synchronously related to the rising edge of PCI
bus clock. IRQSER (SIRQ) pin uses the
electrical specification of PCI bus. Electrical
parameters will follow PCI spec. section 4,
sustained tri-state.
Reset and Initialization
Latency
The IRQSER bus uses RESET_DRV as its reset
signal. The IRQSER pin is tri-stated by all agents
while RESET_DRV is active. With reset,
IRQSER Slaves are put into the (continuous)
IDLE mode. The Host Controller is responsible
for starting the initial IRQSER Cycle to collect
system’s IRQ/Data default values. The system
then follows with the Continuous/Quiet mode
protocol (Stop Frame pulse width) for
subsequent IRQSER Cycles. It is Host
Controller’s responsibility to provide the default
values to 8259’s and other system logic before
the first IRQSER Cycle is performed.
For
IRQSER system suspend, insertion, or removal
application, the Host controller should be
programmed into Continuous (IDLE) mode first.
This is to guarantee IRQSER bus is in IDLE state
before the system configuration changes.
Latency for IRQ/Data updates over the IRQSER
bus in bridge-less systems with the minimum
IRQ/Data Frames of seventeen, will range up to
96 clocks (3.84μS with a 25MHz PCI Bus or
2.88uS with a 33MHz PCI Bus). If one or more
PCI to PCI Bridge is added to a system, the
latency for IRQ/Data updates from the secondary
or tertiary buses will be a few clocks longer for
synchronous buses, and approximately double
for asynchronous buses.
EOI/ISR Read Latency
Any serialized IRQ scheme has a potential
implementation issue related to IRQ latency. IRQ
latency could cause an EOI or ISR Read to
precede an IRQ transition that it should have
BIOS BUFFER
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 nROMOE. The enable
input, nROMCS, can be used to disable the
transfer and isolate the buses.
The chip contains one 245 type buffer that can be
used for a BIOS Buffer. If the BIOS buffer is not
used, then nROMCS must be tied high or pulled
up to Vcc with a resistor so as not to interfere with
the boot ROM.
This function allows data
nROMCS
L
L
H
nROMOE
L
H
X
DESCRIPTION
RD[0:7] data to SD[0:7] bus
SD[0:7] data to RD[0:7]
Isolation
121
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.
RD Bus Functionality
The following cases described below illustrate the
use of the RD Bus.
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.
Case 3: nROMCS as GPIO function. (nROMCS
internally tied to VDD.) The RD bus
floats - cannot use as a bus. Any pin can be
programmed as an alternate function.
Case 4: nROMCS and nROMOE as GPIO
function. Same as Case 3.
Case 2: nROMOE as GPIO 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
Case 5: Parallel IRQ enabled; RD Bus pins,
nROMOE, nROMCS are used as IRQ pins.
107
GENERAL PURPOSE I/O
and an 8-bit configuration control register. The
data register for each GPIO port is represented as
a bit in one of three 8-bit GPIO DATA Registers,
GP1, GP5, and GP6. All of the GPIO registers are
located in Logical Device Block No. 8 in the
FDC37B78x device configuration space. The
GPIO DATA Registers are also optionally
available at different addresses when the
FDC37B78x is in the Run state. The GPIO ports
with their alternate functions and configuration
state register addresses are listed in. Note: three
bits 5-7 of GP5 are not implemented.
The FDC37B78x provides a set of flexible
Input/Output control functions to the system
designer through the 21 dedicated independently
programmable General Purpose I/O pins (GPIO).
The GPIO pins can perform simple I/O or can be
individually configured to provide predefined
alternate functions.
VBAT Power-On-Reset
configures all GPIO pins as non-inverting inputs.
Description
Each GPIO port requires a 1-bit data register
TABLE 52 - GENERAL PURPOSE I/O PORT ASSIGNMENTS
PIN NO.
QFP
77
78
79
80
81
82
4
6
39
2
91
92
83
84
85
86
87
88
89
90
DEFAULT
FUNCTION
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
PCI_CLK
5
DRVDEN1
2
nROMCS
2
nROMOE
2,3
RD0
2,3
RD1
2,3
RD2
2,3
RD3
2,3
RD4
2,3
RD5
2,3
RD6
2,3
RD7
ALT.
FUNC. 1
nSMI
nRING
WDT
LED
IRRX2
IRTX2
nMTR1
nDS1
IRQ14
GPIO
IRQ11
IRQ12
IRQ1
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
IRQ8
IRQ10
ALT.
FUNC. 2
1
EETI
P17
GPIO
IRQ8
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
GPIO
ALT.
FUNC. 3
1
EETI
nSMI
1
EETI
1
EETI
nSMI
LED
nRING
WDT
P17
-
DATA
REGISTER
4
(HEX)
GP1
(CRF6)
GP5
(CRF9)
GP6
(CRFA)
DATA
REGISTER
BIT NO.
0
1
2
3
4
5
6
7
0
2
3
4
0
1
2
3
4
5
6
7
CONFIG.
4
REGISTER
(HEX)
CRE0
CRE1
CRE2
CRE3
CRE4
CRE5
CRE6
CRE7
CRC8
CRCA
CRCB
CRCC
CRD0
CRD1
CRD2
CRD3
CRD4
CRD5
CRD6
CRD7
Note 1. Refer to the section on Either Edge Triggered Interrupt Inputs.
Note 2. At power-up, RD0-7, nROMCS and nROMOE function as the XD Bus. To use RD0-7 for
alternate functions, nROMCS must stay high until those pins are finished being programmed.
Note 3. These pins cannot be programmed as open drain pins in their original function.
Note 4. The GPIO Data and Configuration Registers are located in Logical Device 8.
Note 5: This pin defaults to its GPIO function. See Configuration Registers.
when the chip is in the run state if CR03 Bit[7] = 1.
RUN STATE GPIO DATA REGISTER ACCESS
The host uses an Index and Data port to access
these registers. The Index and Data port powerThe GPIO data registers as well as the Watchdog
on default addresses are 0xEA and 0xEB
Timer Control, and the Soft Power Enable and
respectively. In the configuration state the Index
Status registers can be accessed by the host
123
and Data port addresses are used to access the
GPIO data, Soft Power Status and Enable, and
the Watchdog Timer Control registers.
port address may be re-programmed to 0xE0,
0xE2, 0xE4 or 0xEA; the Data port address is
automatically set to the Index port address + 1.
Upon exiting the configuration state the new Index
For example, to access the GP1 data register
when in the run state, the host should perform an
I/O Write of 0x01 to the Index port address (0xEX)
to select GP1 and then read or write the Data port
(at Index+1) to access the GP1 register.
Generally, to access any GPIO data register GPx
the host should perform an I/O Write of 0x0X to
the Index port address and then access GPX
through the Data port. The Soft Power and
Watchdog Timer Control registers are accessed
similarly.
PORT
NAME
Index
Data
TABLE 53 - INDEX AND DATA PORTS
PORT
ADDRESS
RUN STATE ACCESS
0xE0, E2, E4, EA
0x01-0x0F
Index address + 1
Access to GP1, Watchdog Timer Control,
GP5, GP6, and the Soft Power Status and
Enable registers (see TABLE 54).
TABLE 54 - RUN STATE ACCESSABLE CONFIGURATION REGISTERS
RUN STATE REGISTER
1
ADDRESS (INDEX)
REGISTER (CONFIGURATION STATE ADDRESSING )
0x01
GP1 (L8 - CRF6)
0x03
Note 1:
Watchdog Timer Control (L8 - CRF4)
0x05
GP5 (L8 - CRF9)
0x06
GP6 (L8 - CRFA)
0x08
Soft Power Enable Register 1 (L8-CRB0)
0x09
Soft Power Enable Register 2 (L8-CRB1)
0x0A
Soft Power Status Register 1 (L8-CRB2)
0x0B
Soft Power Status Register 2 (L8-CRB3)
These registers can also be accessed through the configuration registers L8 - CRxx, as shown,
when the FDC37B78x is in the configuration state.
125
GPIO CONFIGURATION
The state of the GPIO polarity bit[1], except for the
EETI function.
Each GPIO port has an 8-bit configuration register
that controls the behavior of the pin. The GPIO
configuration registers are only accessible when
the FDC37B78x is in the Configuration state; more
information can be found in the Configuration
section of this specification.
The interrupt channel for the group Interrupts is
selected by the GP_INT[2:1] configuration
registers defined in the FDC37B78x Configuration
Register Section. The group interrupts are the
"ORed" function of the group interrupt enabled
GPIO ports and will represent a standard ISA
interrupt (edge high). GPIO Group 1 and 2
Interrupts can generate SMI events, wake-up
events through the Soft Power Management logic,
and SCI/PME events. See the ACPI, PME and
SMI section for details. When the group interrupt is
enabled on a GPIO input port, the interrupt
circuitry contains a selectable digital debounce
filter so that switches or push-buttons may be
directly connected to the chip. The debounce
filters reject signals with pulse widths ≤1ms and
are enabled per interrupt group in the GP_INT[2:1]
configuration registers.
Each GPIO port may be configured as either an
input or an output. If the pin is configured as an
output, it can be programmed as open-drain or
push-pull. Inputs and outputs can be configured
as non-inverting or inverting and can be
programmed to generate an interrupt. GPIO ports
can also be configured as a pre-defined alternate
function.
Bit[0] of each GPIO Configuration
Register determines the port direction, bit[1]
determines the signal polarity, bits[4:3] select the
port function, bit[5] enables the interrupt, and bit[7]
determines the output driver type select. The
GPIO configuration register Output Type select
bit[7] applies to GPIO functions, the Watchdog
Timer WDT, the LED and the nSMI Alternate
functions. The basic GPIO configuration options
are summarized in TABLE 55. For Alternate
functions, the pin direction is set and controlled
internally, regardless of the state of the GPIO
Direction bit[0]. Also, selected Alternate INPUT
functions cannot be inverted, regardless of
The state of unconnected GPIO alternate input
functions is inactive. For example, if bits[4:3] in
LD8 -CRCB are not “00”, i.e. nROMCS is not the
selected function for GP53, internally the state of
nROMCS is inactive, “1”.
126
TABLE 55 - GPIO CONFIGURATION SUMMARY
GROUP
INT.
SELECTED
DIRECTION
POLARITY
ENABLE
FUNCTION
BIT
BIT
BIT
DESCRIPTION
B0
B1
B5
GPIO
0
0
0
Pin is a non-inverted output with
the Interrupt disabled.
0
0
1
Pin is a non-inverted output with
the Interrupt enabled.
0
1
0
Pin is an inverted output with the
Interrupt disabled.
0
1
1
Pin is a inverted output with the
Interrupt enabled.
1
0
0
Pin is a non-inverted input with the
Interrupt disabled.
1
0
1
Pin is a non-inverted input with the
Interrupt enabled.
1
1
0
Pin is an inverted input with the
Interrupt disabled.
1
1
1
Pin is a inverted input with the
Interrupt enabled.
ALT.
X1
0
0
Non-inverted alternate function
with Interrupt disabled.
0
1
Non-inverted alternate function
with Interrupt enabled.
12
0
Alternate OUTPUT functions are
inverted, Alternate INPUT
functions are non-inverted;
Interrupts are disabled.
1
Alternate OUTPUT functions are
inverted, Alternate INPUT
functions are non-inverted;
Interrupts are enabled.
Note 1. For alternate function selects, the pin direction is set and controlled internally; i.e., regardless of
the state of the GPIO configuration register Direction bit.
Note 2. For alternate function selects, INPUT functions cannot be inverted, regardless of the state of the
GPIO polarity bit, except for the EETI function.
126
GPIO OPERATION
The operation of the GPIO ports is illustrated in FIGURE 3. Note: FIGURE 3 is for illustration purposes
only and is not intended to suggest specific implementation details.
SD-bit
GPIO
Configuration
Register bit-1
GPIO
Configuration
(Polarity)
(Input/Output)
Register bit-0
D-TYPE
D
Q
GPx_nIOW
0
Transparent
Q
1
1
D
0
GPx_nIOR
GPIO
Data Register
Bit-n
GPIO
Configuration
Register bit-2 or 5
(GROUP INT. ENABLE)
GP Group Interrupts (1 or 2)
FIGURE 3 - GPIO FUNCTION ILLUSTRATION
127
GPIO
PIN
When a GPIO port is programmed as an output,
the logic value or the inverted logic value that has
been written into the GPIO data register is output
to the GPIO pin. Reading from a GPIO port that is
programmed as an output returns the last value
written to the data register.
When a GPIO port is programmed as an input,
reading it through the GPIO data register latches
either the inverted or non-inverted logic value
present at the GPIO pin. Writing to a GPIO port
that is programmed as an input has no effect.
TABLE 56 - GPIO READ/WRITE BEHAVIOR
HOST OPERATION
GPIO INPUT PORT
GPIO OUTPUT PORT
READ
LATCHED VALUE OF GPIO PIN LAST WRITE TO GPIO DATA
REGISTER
WRITE
NO EFFECT
BIT PLACED IN GPIO DATA
REGISTER
128
8042 KEYBOARD CONTROLLER DESCRIPTION
concentrates on the 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.
A Universal Keyboard Controller designed for
intelligent keyboard management in desktop
computer applications is implemented.
The
Universal Keyboard Controller uses an 8042
microcontroller CPU core.
This section
8042A
LS05
P27
P10
P26
TST0
P23
TST1
KDAT
P22
P11
MDAT
KCLK
MCLK
Keyboard and Mouse Interface
KIRQ is the Keyboard IRQ
MIRQ is the Mouse IRQ
Port 21 is used to create a GATEA20 signal from
the FDC37B78x.
130
and the Status register, Input Data register, and
Output Data register. TABLE 57 shows how the
interface decodes the control signals. In addition
to the above signals, the host interface includes
keyboard and mouse IRQs.
KEYBOARD ISA INTERFACE
The FDC37B78x ISA interface is functionally
compatible with the 8042-style host interface. It
consists of the D0-7 data bus; the nIOR, nIOW
TABLE 57 - ISA I/O ADDRESS MAP
nIOW
nIOR
BLOCK
FUNCTION (NOTE 1)
0
1
KDATA
Keyboard Data Write (C/D=0)
1
0
KDATA
Keyboard Data Read
0x64
0
1
KDCTL
Keyboard Command Write (C/D=1)
1
0
KDCTL
Keyboard Status Read
Note 1:These registers consist of three separate 8 bit registers. Status, Data/Command Write and Data
Read.
ISA ADDRESS
0x60
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.
CPU-to-Host Communication
The FDC37B78x 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 58.
8042 INSTRUCTION
OUT DBB
Table 58 - Host Interface Flags
FLAG
Set OBF, and, if enabled, the KIRQ output signal goes high
130
PS/2 mouse products that employ the same type
of interface. To facilitate system expansion, the
FDC37B78x provides four signal pins that may be
used to implement this interface directly for an
external keyboard and mouse.
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.
The FDC37B78x has four high-drive, open-drain
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.
KIRQ
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 FDC37B78x CPU has written to
the output data register via "OUT DBB,A". If P24
is set to a zero, 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.)
KEYBOARD POWER MANAGEMENT
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.
If "EN FLAGS” has not been executed: KIRQ can
be controlled by writing to P24. Writing a zero to
P24 forces KIRQ low; a high forces KIRQ high.
Soft Power Down Mode
MIRQ
If "EN FLAGS" has been executed and P25 is set
to a one:; IBF is inverted and gated onto MIRQ.
The MIRQ signal can be connected to system
interrupt to signify that the FDC37B78x CPU has
read the DBB register.
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 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.
If "EN FLAGS” has not been executed, MIRQ is
controlled by P25, Writing a zero to P25 forces
MIRQ low, a high forces MIRQ high. (MIRQ is
normally selected as IRQ12 for mouse support).
Gate A20
A general purpose P21 is used as a software
controlled Gate A20 or user defined output.
Hard Power Down Mode
EXTERNAL
INTERFACE
KEYBOARD
AND
MOUSE
Hard Power Down Mode is entered by executing a
STOP instruction. Disabling the oscillator driver
cell stops the oscillator. 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
Industry-standard PC-AT-compatible keyboards
employ a two-wire, bidirectional TTL interface for
data transmission. Several sources also supply
131
(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 stabilize. Program execution will
resume as above.
Host I/F Data Register
The Input Data and Output Data registers 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.
INTERRUPTS
The FDC37B78x provides the two 8042 interrupts,
the IBF and the Timer/Counter Overflow.
MEMORY CONFIGURATIONS
Host I/F Status Register
The FDC37B78x provides 2K of on-chip ROM and
256 bytes of on-chip RAM.
The Status register is 8 bits wide. TABLE 59
shows the contents of the Status register.
Register Definitions
D7
UD
D6
UD
D5
UD
TABLE 59 - STATUS REGISTER
D4
D3
D2
UD
C/D
UD
132
D1
IBF
D0
OBF
OBF(Output Buffer Full) - This flag is set to
whenever the FDC37B78x 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
FDC37B78x CPU.
EXTERNAL CLOCK SIGNAL
UDWritable by FDC37B78x CPU. These bits are
user-definable.
The FDC37B78x Keyboard Controller 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 (Vcc POR) and externally
generated reset signals. In powerdown mode, the
external clock signal 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
FDC37B78x CPU's nIBF (MIRQ) interrupt if
enabled. When the FDC37B78x 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.
DEFAULT RESET CONDITIONS
The FDC37B78x has one source of reset: an
external reset via the RESET_DRV pin. Refer to
TABLE 60 for the effect of each type of reset on
the internal registers.
TABLE 60 - RESETS
DESCRIPTION
HARDWARE RESET (RESET)
KCLK
Input
KDAT
Input
MCLK
Input
MDAT
Input
Host I/F Data Reg
N/A
Host I/F Status Reg
00H
N/A: Not Applicable
133
PORT 92 FAST GATEA20 AND KEYBOARD
RESET
GATEA20 AND KEYBOARD RESET
The FDC37B78x provides two options for
GateA20 and Keyboard Reset: 8042 Software
Generated GateA20 and KRESET 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.
This register is used to support the alternate
reset (nALT_RST) and alternate A20 (ALT_A20)
functions.
Name
Location
Default Value
Attribute
Size
Bit
7:6
5
4
3
2
1
0
Port 92
92h
24h
Read/Write
8 bits
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 active (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.
134
nGATEA20
8042
P21
0
0
1
1
ALT_A20
0
1
0
1
System
nA20M
0
1
1
1
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).
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.
If Port 92 is enabled, i.e., bit 2 of KRST_GA20 is
set to 1, then a pulse is generated by writing a 1
to bit 0 of the Port 92 Register and this pulse is
AND’ed with the pulse generated from the 8042.
This pulse is output on pin KRESET and its
polarity is controlled by the GPI/O polarity
configuration.
135
14us
~
~
6us
8042
P20
KRST
KBDRST
KRST_GA20
Bit 2
P92
nALT_RST
Bit 0
Pulse
Gen
14us
~
~
Note: When Port 92 is disabled,
writes are ignored and reads
return undefined values.
6us
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.
8042 P17 Functions
8042 function P17 is implemented as in a true
8042 part. Reference the 8042 spec 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.
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., P17 and nSMI can be externally tied together.
In 8042 mode, the pins cannot be programmed as
input nor inverted through the GP configuration
registers.
136
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
Gate A20 Turn-On Sequence Timing
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.
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
112
register, Input Data register, and Output Data
register. Table 61 shows how the interface
decodes the control signals. In addition to the
above signals, the host interface includes
keyboard and mouse IRQs.
RTC INTERFACE
The ISA interface is functionally compatible with
the 8042-style host interface. It consists of the D07 data bus, the nIOR, nIOW and the Status
Table 61 - ISA I/O Address Map
Addresses 0x60, 0x64, 0x70 and 0x71 are qualified by AEN
ISA ADDRESS*
BLOCK
FUNCTION
0x70 (R/W)
RTC
Address Register
0x71 (R/W)
RTC
Data Register
Base*
RTC Bank 1 Address Register
Base* + 1
RTC Bank 1 Data Register
*Bank 0 is at 70h. Bank 1 is relocatable via the RTC Mode Register and the Secondary Base Address for
RTC Bank 1 (CR62 and CR63). See Configuration section.
RTC Address Register
OSCILLATOR
Writing to this register sets the CMOS address
that will be read or written.
Crystal Oscillator input. A 32.768 kHz crystal
connected externally on the XTAL1 and XTAL2
pins generates the 32.768 kHz RTC input clock.
Maximum clock frequency is 32.768 KHz.
RTC Data Register
RTC Reset
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 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:
REAL TIME CLOCK
The Real Time Clock is a complete time of day
clock with a day of month alarm, calendar (up to
the year 9999), a programmable periodic interrupt,
and a programmable square wave generator.
1)
2)
Features
3)
Counts seconds, minutes, and hours of the day.
Counts days of the week, date, month, year and
century.
Day of Month 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.
Port Definition and Description
4)
5)
6)
7)
8)
9)
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
accessible.
Alarm Interrupt Flag (AF) is cleared to 0.
nIRQ pin is in high impedance state.
When RESET_DRV is active and the battery
voltage is below 1-volt nominal, the following
occurs:
138
1.
2.
Registers 00-0D are initialized to 00h.
Access to all registers from the host are
blocked.
The RTC Interrupt is brought out by programming
the RTC Primary Interrupt Select 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.
RTC Interrupt
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.
ADDRESS
0
1
2
3
4
5
6
7
8
9
A
B
C
D
0E-7Ch
7Dh
7Eh
7Fh
Internal Registers
Table 62 shows the address map for bank 0 of the
RTC; time, calendar, alarm, control, status bytes
and 114 bytes of "CMOS" registers.
Table 62 - Real Time Clock Address Map, Bank 0
REGISTER TYPE
REGISTER FUNCTION
R/W
Register 0: Seconds
R/W
Register 1: Seconds Alarm
R/W
Register 2: Minutes
R/W
Register 3: Minutes Alarm
R/W
Register 4: Hours
R/W
Register 5: Hours Alarm
R/W
Register 6: Day of Week
R/W
Register 7: Date of Month
R/W
Register 8: Month
R/W
Register 9: Year
R/W
Register A:
R/W
Register B: (Bit 0 is Read Only)
R
Register C:
R/W
Register D:VRT and Day of Month Alarm
R/W
Register E-7C: General Purpose
R/W
Register 7D: Century Byte
R/W
Register 7E: Control Register 1
R/W
Register 7F:General Purpose
All 14 bytes are directly writable and readable by the host with the following exceptions:
a.
b.
c.
Register C is read only
Bit 7 of Register A and Bit 7 of Register D are read only
Bit 0 of Register B is read only
139
All 128 bytes are directly writeable and readable
by the host.
Table 63 shows Bank 1, the second bank of
CMOS registers which contains an additional 128
bytes of general purpose CMOS registers.
ADDRESS
0-7F
Table 63 - Real Time Clock Address Map, Bank 1
REGISTER TYPE
REGISTER FUNCTION
R/W
Register 0-7F: General Purpose
Note: CMOS Bank 1 is relocatable via the RTC Mode Register and the Secondary Base Address (CR62
and CR63). See Configuration Section.
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 65. The update logic contains circuitry for
automatic end-of-month recognition as well as
automatic leap year compensation.
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 time, calendar, century and alarm bytes can be
in binary or BCD as shown in Table 64.
An alarm can be generated for day of month, day,
hour, minute, or seconds. The alarm may be used
in two ways. First, when the program inserts an
alarm time in the appropriate date, 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 and date alarm location. Similarly, an alarm
is generated every minute with "don't care" codes
in the hours, date and minutes alarm bytes. The
"don't care" codes in all three alarm bytes create
an
interrupt
every
second.
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.
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 hour
format is selected, the high order bit of the hours
byte represents PM when it is a "1".
Once per second, the time, calendar and alarm
bytes, as well as the century byte switched to the
140
ADD
0h
1h
2h
3h
4h
5h
6h
7h
8h
9h
Dh
7Dh
7Eh
Table 64 - Time, Calendar and Alarm Bytes
REGISTER FUNCTION
BCD RANGE
Register 0: Seconds
00-59
Register 1: Seconds Alarm
00-59
Register 2: Minutes
00-59
Register 3: Minutes Alarm
00-59
Register 4: Hours
01-12 am
(12 hour mode)
81-92 pm
(24 hour mode)
00-23
Register 5: Hours Alarm
01-12 am
(12 hour mode)
81-92 pm
(24 hour mode)
00-23
Register 6: Day of Week
01-07
Register 7: Day of Month
01-31
Register 8: Month
01-12
Register 9: Year
00-99
Date of Month Alarm
1-31
Century Byte
00-99
Control Register 1
BINARY RANGE
00-3B
00-3B
00-3B
00-3B
01-0C
81-8C
00-17
01-0C
81-8C
00-17
01-07
01-1F
01-0C
00-63
01-1F
00-63
Wake-up Alarm Function
Update Cycle
The Alarm can 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. The Alarm wake-up function is enabled
via the Alarm Enable bit, AIE. The Alarm
Remember Enable bit, AL_REM_EN, in the RTC
Control Register 1, is used to power-up the
system upon return of power if the Alarm time
has passed during loss of power. These bits
function as follows:
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 primary function of the update cycle is to
increment the seconds’ byte, check for overflow,
and increment the minute’s 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.
If VTR is present: AIE controls whether or not
the alarm is enabled as a wake-up function. If
AIE is set and VTR=5V, the nPowerOn pin will
go active (low) when the date/time is equal to the
alarm date/time and the power supply will turn on
the machine.
The length of an update cycle is shown in Table
65. 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 μs later. Therefore, if a low is read on the UIP
bit, the user has at least 244 μs before
time/calendar data will be changed.
If VTR is not present: AL_REM_EN controls
whether or not the alarm will power-up the
system upon the return of VTR, regardless of the
value of AIE. If AL_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 power-up.
141
Table 65 - Update Cycle Time
INPUT CLOCK
FREQUENCY
32.768 kHz
32.768 kHz
UIP BIT
1
0
UPDATE CYCLE TIME
1948 μs
-
MINIMUM TIME
UPDATE CYCLE
244 μs
when Bank 0 is enabled, even during the update
cycle. Note Register D, Bits[6:0] are not accessible
during an update cycle.
CONTROL AND STATUS REGISTERS, BANK 0
Bank 0 of the RTC has five registers that are
accessible to the processor program at all times
REGISTER A (AH)
MSB
b7
UIP
b6
DV2
b5
DV1
b4
DV0
b3
RS3
b2
RS2
b1
RS1
LSB
b0
RS0
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.
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 244 μs. 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 66.
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 67 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 66 shows the allowable combinations. The
divider selection bits are also used to reset the
111
Table 66 - Divider Selection Bits
REGISTER A BITS
DV2
DV1
DV0
MODE
Reset Divider
0
0
0
Reset Divider
1
0
0
Normal Operate
0
1
0
Test
1
1
0
Test
X
0
1
Reset Divider
X
1
1
OSCILLATOR
FREQUENCY
32.768 KHz
32.768 KHz
32.768 KHz
32.768 KHz
32.768 KHz
RATE SELECT
RS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
RS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
REGISTER B (BH)
MSB
b7
b6
SET
PIE
RS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Table 67 - Periodic Interrupt Rates
32.768 KHz TIME BASE
PERIOD RATE OF
FREQUENCY OF
RS0
INTERRUPT
INTERRUPT
0
0.0
1
3.90625 ms
256 Hz
0
7.8125 ms
128 Hz
1
8.192 KHz
122.070 μs
0
4.096 KHz
244.141 μs
1
2.048 KHz
488.281 μs
0
1.024 KHz
976.562 μs
1
1.953125 ms
512 Hz
0
3.90625 ms
256 Hz
1
7.8125 ms
128 Hz
0
15.625 ms
64 Hz
1
31.25 ms
32 Hz
0
62.5 ms
16 Hz
1
125 ms
8 Hz
0
250 ms
4 Hz
1
500 ms
2 Hz
b5
AIE
b4
UIE
b3
RES
b2
DM2
b1
24/12
LSB
b0
DSE
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.
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
SET
143
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.
RES
Reserved - read as “0”.
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.
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
"0". The AIE bit is not affected by any internal
functions.
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.
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.
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.
REGISTER C (CH) - READ ONLY REGISTER
MSB
b7
IRQF
b6
PF
b5
AF
b4
UF
b3
0
b2
0
b1
0
LSB
b0
0
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.
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
AF
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.
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.
PF
The periodic interrupt flag is a read-only bit which
is set to a "1" when a particular edge is detected
145
UF
b3-0
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.
The unused bits of Register C are read as zeros
and cannot be written.
REGISTER D (DH) - BITS[7,6] ARE READ-ONLY, BITS[5:0] ARE READ/WRITE
MSB
b7
VRT
b6
0
b5
b4
b3
b2
Date Alarm
b1
LSB
b0
VRT
b5:b0
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 a
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.
Date Alarm; These bits store the date of month
alarm value. If set to 000000b, then a don’t care
state is assumed. The host must configure the
date alarm for these bits to do anything, yet they
can be written at any time. If the date alarm is
not enabled, these bits will return zeros. These
bits are not affected by RESET_DRV.
Note: Bits[6:0] are not accessible during an update
cycle.
b6
REGISTER 7E (7Eh) CONTROL REGISTER 1
Read as zero and cannot be written.
Default is 0; cleared upon Vbat POR. This
register is battery backed-up.
D7
XTAL_
CAP
D6
0
D5
0
D4
0
D3
0
145
D2
VTR_POR
_EN
D1
VTR_POR
_OFF
D0
AL_REM_
EN
The RTC includes three separate fully- automatic
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.
BIT 0 - AL_REM_EN
One of the two control bits for the alarm 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
wake-up function, AlE.
If AL_REM_EN is set and VTR=0 at the date/time
that the alarm is set for, the nPowerOn pin will go
active (low) and the machine will power-up as
soon as VTR comes back.
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.
Bit 1 – VTR_POR_OFF
If VTR_POR_OFF is set, the nPowerOn pin will go
inactive (float) and the main power (Vcc) will
remain off when the VTR POR occurs. The
software must not set VTR_POR_OFF and
VTR_POR_EN at the same time.
BIT 2 - VTR_POR_EN
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.
The
software
must
not
set
VTR_POR_OFF and VTR_POR_EN at the same
time.
Bits 3:6 - Reserved
Read as zero, ignore writes
Bit 7 - XTAL_CAP
This bit is used to specify the 32Khz XTAL load
capacitance (12pF vs. 6pF):
0=12pF, 1=6pF.
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.
Registers 0Eh-7Ch, 7Fh in Bank 0 and 00h-7Fh
in Bank 1: General Purpose
Registers 0Eh-7Ch, 7Fh in Bank 0 and 00h-7Fh in
Bank 1 are general purpose CMOS registers.
These registers can be used by the host and are
fully available during the time update cycle. The
contents of these registers are preserved by the
battery power.
Frequency Divider
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
Interrupts
146
66 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.
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 67 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.
147
SOFT POWER MANAGEMENT
section. The chip can also be programmed to
always stay off when the AC power returns. (See
VTR_POR_OFF in the RTC section.)
This chip 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. 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).
Configuration registers L8-CR_B0 and L8CR_B1 select the wakes-up events (SPx). The
Configuration registers L8-CR_B2 and L8CR_B3 indict the wake-up event status. The
possible wake-events are:
The implementation of Soft Power Management is
illustrated in Figure 11. A high to low 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. This is
accomplised by an alarm event that has already
passed (if the alarm 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
•
•
•
•
•
•
•
•
•
•
148
UART1 and UART 2 Ring Indicator Pin
Keyboard and Mouse clock Pin
Group Interrupt 1, Group Interrupt 2
IRRX2 input pin
RTC Alarm
UART 1 and UART 2 Receive Data Pin
nRING pin
Consumer IR (CIR)
Power Button input pin
VTR_POR
FIGURE 3 - SOFT POWER MANAGEMENT FUNCTIONAL DIAGRAM
nBINT
Button
OFF_EN
OFF_DLY
Delay2
nSPOFF1
Logic
nSPOFF
L
VTR_POR_EN
VTR POR
AL_REM_EN
Button Input
SP1
Logic
Alarm
ED; PG
Delay1
OFF_DLY
VTR
ED; L
Flip
Flop 1
D
EN1
nSPOFF1
Q
CLR
VTR_POR_OFF
VTR POR
VBAT POR
SPx
ED; L
ENx
nSPOFF1
Soft Power
Off nSPOFF1
nPowerOn
Open Collector
Type Output
Logic
VTR POR With
Vbat<1.2V
PWRBTNOR_EN
Override
PWRBTNOR_STS
Timer
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, a Vbat POR, a VTR POR with Vbat<1.2V, or Power Button Override Event causes
nPowerOn to float.
ED;PG = Edge Detect, Pulse Generator
ED;L = Edge Detect and Latch
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 AL_REM_EN Bit description in the
RTC Control Register section for more information.
Note 4: A battery backed-up enable bit in the alarm control register can be set to force Flip Flop 1 to
come up ‘off’ after a VTR POR, see VTR_POR_OFF.
149
2. 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. All soft power
management configuration registers are battery
backed up and are reset on Vbat POR.
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.
Soft Power Enable Registers
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 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.
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
bits and enable bits associated with this feature
in the PM1_BLK registers.
See the ACPI
section.
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.
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 to turn off the system. The
override status bit alerts the system upon powerup that an override event was used to power
down the system, and will be used to properly
power-up the system.
Soft Power Status Registers
Soft Power Status Register 1
(Configuration Register B2, Logical Device 8)
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.
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
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
150
timer output will pulse the clear on the Flip Flop
1.
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
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 4 - BLANKING PERIOD
151
ACPI/PME/SMI FEATURES
Power Button With Override
ACPI Features
The power button has a status and and enable
bit in the PM1_BLK of registers to provide an SCI
upon the button press. The power button can
also turn the system on and off through the soft
power management logic. The power button
also has an override event as required by the
ACPI specification.
See The Soft Power
Management Section. This override event is
described as follows: If the user presses the
power button for more than 4 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.
The FDC37B78x supports ACPI as described in
this section. These features comply with the
ACPI Specification, Revision 1.0.
Legacy/ACPI Select Capability
This capability consists of an SMI/SCI switch
which is required in a system that 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, which
consists of run-time registers. Included in the
PM1_BLK is an enable bit, SCI_EN, to allow the
SCI interrupt to be generated upon an enabled
SCI event. This SCI interrupt can be switched
out to the nPME/SCI pin or routed to one of the
parallel interrupts, IRQ11, or any Serial IRQ
frame. Note that the Serial IRQ is not available
under VTR power. The polarity and output type
(open collector or push-pull) of the SCI is
selected through the IRQ MUX Register.
RTC Alarm
The ACPI specification requires that the RTC
alarm generate a hardware wake-up event from
the sleeping state. The RTC alarm event can be
enabled as both a PME and an SCI event
through bits in the PM1_BLK of registers. In
addition, the can also turn the system on due to
the RTC alarm through the soft power
management logic.
There is a bit in the PME Enable Register and
the PME Status Register 1 to enable the RTC
alarm event as a nPME event 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_PME_STS bit will be set.
If the
RTC_PME_EN bit is set, an RTC PME power
management event will be generated.
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. 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). 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.
For SCI, the RTC_STS and RTC_EN bits are in
the PM1_STS and PM1_EN registers.
152
either by main power (Vcc) or standby power
(Vtr), depending on the system sleep state. In
both cases, the part can provide wakeup
capability through the soft power management
logic and generate a nPME or nSCI. In an ACPI
system, the devices are powered on and off
through control methods.
General Purpose ACPI Events
The General Purpose ACPI events are enabled
through the SCI_EN1 bit in the GPE_EN register.
This bit, if set, allows any of the enabled PME
events to generate an SCI. In addition, if the
DEVINT_EN bit in the PME_EN 1 Register is set,
and if the EN_SMI_PME bit in the SMI_EN 2
register is set, then any of the SMI Events can
also generate an SCI. See the SCI/PME and
SMI/PME logic diagrams below.
Wake Events
Wake events are events that turn power on
(activate nPowerOn output) if enabled. These
events can also be enabled as SMI, SCI and
nPME events as shown in the following table. In
addition, these wake events set the WAK_STS
bit if enabled (see ACPI PM1_STS2 Register
description).
Device Sleep States
Each device in the FDC37B78x supports two
device sleep states, D0 (on) and D3 (off). The
D3 state corresponds to the PCI defined D3cold
state. With all devices off, the part is powered
INPUT TO SOFT POWER
SMI/SCI/PME
MANAGEMENT
GENERATION
KCLK
KCLK
SMI/SCI/PME
Pins
MCLK
MCLK
SMI/SCI/PME
IRRX2 (Includes CIR)
IRRX2
SMI/SCI/PME
RXD2/IRRX (Includes CIR)
RXD2/IRRX
SMI/SCI/PME
(CIR)
CIR
SMI/SCI/PME
RXD1
RXD1
SMI/SCI1/PME1
nRI1
nRI1
SMI/SCI/PME
nRI2
nRI2
SMI/SCI/PME
nRING
nRING
SMI/SCI/PME
Button
Button
SMI/SCI2/PME1
GP10-17
GPINT1
SMI/SCI1/PME
GP50-54, GP60-67
GPINT2
SMI/SCI1/PME1
RTC Alarm (includes AL_REM)
RTC Alarm + AL_REM
SCI2
Internal
VTR POR
VTR POR
SCI
Signals
Note 1: These SCI/PME events are SMI events that are enabled through DEVINT_EN
Note 2: These SCI events have Status and Enable bits in the PM1 registers
WAKE EVENTS
The following are SMI events that are not wake events:
•
Floppy Interrupt
•
•
Parallel Port Interrupt
•
•
WDT
•
•
P12
UART1 and UART2 interrupts
Mouse and keyboard interrupts
SLP_EN
Any wakeup logic that affects the configuration of the wakeup events is implemented so that the
configuration of the wakeup events is retained (in the event of total power loss) upon Vtr POR.
153
When PME_EN is inactive, the nPME signal can
not be asserted. When PME_EN is asserted, any
wake source whose individual PME Wake Enable
register bit is asserted can cause nPME to
become asserted. The PME Wake Status register
indicates which wake source has asserted the
nPME signal. The PME Status bit, PME_STS, is
asserted by active transitions of PME Wake
sources. PME_STS will become asserted
independent of the state of the global PME enable,
PME_EN.
PME SUPPORT
The FDC37B78x offers support for PCI power
management events (PMEs).
A power
management event is requested by a PCI function
via the assertion of the nPME signal. The
assertion and deassertion of nPME is
asynchronous to the PCI clock.
In the
FDC37B78x, active transitions on the ring indicator
inputs nRI1 and nRI2 or the nRING pin, valid NEC
infrared remote control frames, active keyboardclock edges, active mouse-clock edges, RTC
alarm, and GPIOs GP10-GP17 can directly assert
the nPME signal. In addition, if the DEVINT_EN bit
in the PME_EN 1 Register is set, and if the
EN_SMI_PME bit in the SMI_EN 2 register is set,
then any of the SMI Events can also generate a
nPME. See the SCI/PME and SMI/PME logic
diagrams in FIGURE 5 and FIGURE 6.
In the FDC37B78x the nPME pin is an open drain,
active low, driver. The FDC37B78x nPME pin is
fully isolated from other external devices that might
pull the PCI nPME signal low; i.e., the PCI nPME
signal is capable of being driven high externally by
another active device or pullup even when the the
FDC37B78x VDD is grounded, providing VTR
power is active. The FDC37B78x nPME driver
sinks 6mA at .55V max (see section 4.2.1.1 DC
Specifications, page 122, in the PCI Local Bus
Specification, Revision 2.1).
nPME functionality is controlled by the runtime
registers
at
<PM1_BLK>+Ch
through
<PM1_BLK>+11h.
The PME Enable bit,
PME_EN, globally controls PME Wake-up events.
(SCI). Any status bit in the ACPI specification
has the following attributes:
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 bit in the enable
register is 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).
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 are a special class
of status bits that have no respective enable bit,
ACPI/PME/SMI REGISTERS
Logical Device A in the configuration section
contains the address pointer to the ACPI power
management register block, and PM1_BLK.
These are run-time registers; Included in the
PM1_BLK is an enable bit to allow the SCI group
interrupt to be routed to any serial interrupt or the
IRQ11 pin, or onto the nPME/SCI pin. Note: See
IRQ mux control register for SCI/PME/SMI
selection function and pin configuration bits.
Register 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
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
154
these are called out specifically, and the
respective enable bit in the enable register is
marked as reserved for these special cases.
of the registers contained in these blocks. All of
these registers are powered by VTR and battery
backed-up and are reset on Vbat POR.
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.
Wakeup Event Configuration is Retained by
Battery Power
To preserve the configuration of the wakeup
functions that were programmed prior to the loss
of Vtr upon its return, the soft power
management registers, PME, SCI, SMI registers
and GPIO registers are all powered by the
battery. These registers are reset to their default
values only on Vbat POR. These registers are
described in the sections below.
TABLE 68 and TABLE 69 list the PM1/GPE and
PME/SMI/MSC register blocks and the locations
156
Register Block
The registers in this block are powered by VTR and battery backed up.
TABLE 68 - PM1/GPE 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
GPE_STS 1
8
<PM1_BLK>+8h
GPE_EN 1
8
<PM1_BLK>+9h
Reserved
8
<PM1_BLK>+Ah
Reserved
8
<PM1_BLK>+Bh
TABLE 69 - PME/SMI/MSC REGISTER BLOCK
Register
Size
Address
PME_STS 1
8
< PM1_BLK>+Ch
PME_STS 2
8
< PM1_BLK>+Dh
PME_EN 1
8
< PM1_BLK>+Eh
PME_EN 2
8
< PM1_BLK>+Fh
PME_STS
8
< PM1_BLK>+10h
PME_EN
8
< PM1_BLK>+11h
SMI_STS 1
8
< PM1_BLK>+12h
SMI_STS 2
8
< PM1_BLK>+13h
SMI_EN 1
8
< PM1_BLK>+14h
SMI_EN 2
8
< PM1_BLK>+15h
MSC_STS
8
< PM1_BLK>+16h
Reserved
8
< PM1_BLK>+17h
TABLE 70 shows the block size and range of base addresses for each block.
TABLE 70 - REGISTER BLOCK ATTRIBUTES
Block Name
Block Size
Base Address Range
PM1_BLK
24-bytes
0-FFF
156
ACPI REGISTERS
In the FDC37B78x, the PME wakeup events can be enabled as SCI events through the SCI_STS1 and
SCI_EN1 bits in the GPE status and enable registers. See PME Interface and SMI/PME/SCI logic
sections.
Power Management 1 Status Register 1 (PM1_STS 1)
Register Location: <PM1_BLK> System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
NAME
DESCRIPTION
0-7
Reserved
Reserved. These bits always return a value of zero.
Note 0: All bits described as "reserved" in writeable registers must be written with the value 0 when the
register is written.
Note 1: This bit is set by hardware and can only be cleared by software writing a one to this bit position
and by Vbat POR. Writing a 0 has no effect.
Power Management 1 Status Register 2 (PM1_STS 2)
Register Location: <PM1_BLK>+1h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
0
BIT
NAME
PWRBTN_STS
1
2
Reserved
RTC_STS
3
PWRBTNOR_STS
DESCRIPTION
This bit is set when the Button_In signal is asserted. In the system
working state, while PWRBTN_EN and PWRBTN_STS are both set
an SCI interrupt event is raised. In the sleeping or soft off state, a
wake-up event is generated (regardless of the setting of
PWRBTN_EN) (Note 2). This bit is only set by hardware and is reset
by software writing a one to this bit position, and by Vbat 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).
Reserved.
This bit is set when the RTC generates an alarm. Additionally if the
RTC_EN bit is set then the setting of the RTC_STS bit will generate
an SCI. When the AL_REM_EN bit is set in the RTC control register
1, then the RTC_STS bit is set due to an RTC alarm event occurring
when Vtr is not present. This will indicate to the OS the cause of the
wakeup event (nPowerOn pin asserted when Vtr returns) caused by
the “alarm remember” logic in the Soft Power Management block.
(Note 1)
This bit is set when the power switch over-ride function is set: If
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.
157
BIT
NAME
DESCRIPTION
(Note 1)
4-6
Reserved
Reserved. These bits always return a value of zero.
7
WAK_STS
This bit is set when the system is in the sleeping state and an
enabled wakeup event occurs. This bit is set on the high-to-low
transition of nPowerOn, if the WAK_CTRL bit in the sleep / wake
configuration register (0xF0 in Logical Device A) is cleared. If the
WAK_CTRL bit is set, then any enabled wakeup event will also set
the WAK_STS bit in addition to the high-to-low transition of
nPowerOn. It is cleared by writing a 1 to its bit location when
nPowerOn is active (low). Upon setting this bit, the system will
transition to the working state. (Note 1)
Note 1: This bit is set by hardware and can only be cleared by software writing a one to this bit position
and by Vbat POR. Writing a 0 has no effect.
Note 2: In the present implementation of Button_In, pressing the button will always wake the machine
(i.e., activate nPowerOn).
Power Management 1 Enable Register 1 (PM1_EN 1)
Register Location: <PM1_BLK>+2 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
0-7
NAME
Reserved
DESCRIPTION
Reserved. These bits always return a value of zero.
Power Management 1 Enable Register 2 (PM1_EN 2)
Register Location: <PM1_BLK>+3 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
NAME
PWRBTN_EN
DESCRIPTION
This bit is used to enable the assertion of the Button_In to generate an
SCI event. The PWRBTN_STS bit is set anytime 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.
1
Reserved
Reserved.
2
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 anytime the RTC generates an alarm.
3-7
Reserved
Reserved. These bits always return a value of zero.
Power Management 1 Control Register 1 (PM1_CNTRL 1)
Register Location: <PM1_BLK>+4 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
0
NAME
SCI_EN
0
DESCRIPTION
When this bit is set, then the SCI enabled power management events will
158
BIT
NAME
1-7
Reserved
DESCRIPTION
generate an SCI interrupt. When this bit is reset power management events
will not generate an SCI interrupt.
Reserved. These bits always return a value of zero.
Power Management 1 Control Register 2 (PM1_CNTRL 2)
Register Location: <PM1_BLK>+5 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
0
1
NAME
Reserved
PWRBTNOR_EN
2-4
SLP_TYPx
5
SLP_EN
6-7
Reserved
DESCRIPTION
Reserved. This field always returns zero.
This bit controls the power button over-ride function. When set, then
anytime the Button_In signal is asserted for more than four seconds the
system will transition to the off state. When a power button over-ride
event occurs, the logic should clear the PWRBTN_STS bit, and set the
PWRBTNOR_STS bit.
This 3-bit field defines the type of hardware sleep state the system
enters when the SLP_EN bit is set to one. When this field is 000 the
FDC37B78x will transition the machine to the off state when the
SLP_EN bit is set to one. That is, with this field set to 000, nPowerOn
will go inactive (float) after a 1-2 RTC clock delay when SLP_EN is set.
This delay is a minimum of one 32kHz clock and a maximum of two
32kHz clocks (31.25μsec-62.5μsec). When this field is any other value,
there is no effect.
This is a write-only bit and reads to it always return a zero. Writing ‘1’ to
this bit causes the system to sequence into the sleeping state
associated with the SLP_TYPx fields after a 1-2 RTC clock delay, if the
SLP_CTRL bit in the sleep / wake configuration register (0xF0 in
Logical Device A) is cleared. If the SLP_CTRL bit is set, do not
sequence into the sleeping state associated with the SLP_TYPx field,
but generate an SMI. Note: the SLP_EN_SMI bit in the SMI Status
Register 2 is always set upon writing ‘1’ to the SLP_EN bit. Writing ‘0’
to this bit has no effect.
Reserved. This field always returns zero.
159
General Purpose Event Status Register 1 (GPE_STS1)
Register Location: <PM1_BLK>+8 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
0
NAME
SCI_STS1
DESCRIPTION
This bit is set when the device power management events (PME events) occur.
When enabled, the setting of this bit will generate an SCI Interrupt (Note 1).
Writing a “1” to this bit will clear it if there are no pending PME events. See
Figure 5.
1-7
Reserved
Reserved. These bits always return a value of zero.
Note 1: This bit is set by hardware and can only be cleared by software writing a one to this bit position
and by Vbat POR. Writing a 0 has no effect.
General Purpose Event Enable Register 1 (GPE_EN1)
Register Location: <PM1_BLK>+9 System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
BIT
0
NAME
SCI_EN1
1-7
Reserved
DESCRIPTION
When this bit is set, then the enabled device power management events (PME
events) will generate an SCI interrupt. When this bit is reset, device power
management events will not generate an SCI interrupt.
Reserved. These bits always return a value of zero.
Note 0: all bits described as "reserved" in writeable registers must be written with the value 0 when the
register is written.
PME Registers
The power management event function has a PME_Status bit and a PME_En bit. These bits are
defined in the PCI Bus Power Management Interface Specification, Revision 1.0, Draft, Copyright ©
1997, PCI Special Interest Group, Mar. 18, 1997.
The default states for the PME_Status and PME_En bits are controlled by Vbat Power-On-Reset.
PME Status Register (PME_STS)
Register Location: <PM1_BLK>+10h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
D7
•
D6
D5
D4
D3
RESERVED
D2
D1
D0
PME_Status
DEFAULT
0x00
The PME_Status bit is set when the FDC37B78x would normally assert the PCI nPME signal,
independent of the state of the PME_En bit. Only active transitions on the PME Wake sources can
set the PME_Status bit.
160
•
•
•
The PME_Status bit is read/write-clear. Writing a “1” to the PME_Status bit will clear it (if there are
no pending PME events) and cause the FDC37C78X to stop asserting the nPME, if enabled. See
Figure 5.
Writing a “0” has no effect on the PME_Status bit.
The PME_Status bit is reset to “0” during VBAT Power-On-Reset.
PME Enable Register (PME_EN)
Register Location: <PM1_BLK>+11h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
D7
•
•
•
D6
D5
D4
D3
RESERVED
D2
D1
D0
PME_En
DEFAULT
0x00
Setting the PME_En bit to “1” enables the FDC37B78x to assert the nPME signal.
When the PME_En bit is reset to “0”, nPME signal assertion is disabled.
The PME_En bit is reset to “0” during VBAT Power-On-Reset.
PME Status Register 1 (PME_STS 1)
Register Location: <PM1_BLK>+Ch System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
D7
DEVINT
_STS
D6
RTC_PME
_STS
D5
nRING
D4
MOUSE
D3
KBD
D2
RI1
D1
RI2
D0
CIR
DEFAULT
0x00
PME Status Register 2 (PME_STS2)
Register Location: <PM1_BLK>+Dh System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
•
•
D7
D6
D5
D4
D3
D2
D1
D0
GP17
GP16
GP15
GP14
GP13
GP12
GP11
GP10
DEFAUL
T
0x00
The PME Status registers indicate the state of the individual FDC37B78x PME wake sources,
independent of the state of the individual source enables or the PME_En bit.
If the wake source has asserted a wake event, the associated PME Status bit will be “1”. The wake
source bits in the PME Status registers are read/write-clear: an active (“1”) PME Status bit can only
be cleared by writing a “1” to the bit. Writing a “0” to bits in the PME Wake Status register has no
effect.
PME Enable Register 1 (PME_EN1)
Register Location: <PM1_BLK>+Eh System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
161
Size: 8-bits
D7
DEVINT_
EN
D6
RTC_PME
_EN
D5
nRING
D4
MOUSE
D3
KBD
D2
RI1
D1
RI2
D0
CIR
DEFAULT
0x00
PME Enable Register 2 (PME_EN2)
Register Location: <PM1_BLK>+Fh System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
D7
GP17
•
•
•
D6
GP16
D5
GP15
D4
GP14
D3
GP13
D2
GP12
D1
GP11
D0
GP10
DEFAULT
0x00
The PME Enable registers enable the individual FDC37B78x wake sources onto the nPME bus.
When the PME Enable register bit for a wake source is active (“1”), if the source asserts a wake
event and the PME_En bit is “1”, the source will assert the PCI nPME signal.
When the PME Enable register bit for a wake source is inactive (“0”), the PME Status register will
indicate the state of the wake source but will not assert the PCI nPME signal.
SMI Registers
The FDC37B78x implements a group nSMI output pin. The nSMI group interrupt output consists of the
enabled interrupts from each of the functional blocks in the chip plus other SMI events. 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 or Serial IRQ Frame (IRQ2) via bit[7] in the SMI Enable
Register 2. These SMI events can also be enabled as nPME/SCI events by setting the EN_SMI_PME
bit, bit[6] of SMI Enable Register 2.
This register is also used to enable the group nSMI output onto the nSMI Serial/Parallel IRQ pin and the
routing of 8042 P12 internally to nSMI.
The IRQ mux Register Bit 7 is used to select the SMI on the SMI pin or the Serial IRQ frame.
162
SMI Status Register 1 (SMI_STS1)
Register Location: <PM1_BLK>+12h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write
Size: 8-bits
NAME
SMI Status Register 1
DESCRIPTION
This register is used to read the status of the SMI inputs.
Default = 0x00
on Vbat POR
The following bits must be cleared at their source.
Bit[0] Reserved
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)
SMI Status Register 2 (SMI_STS2)
Register Location: <PM1_BLK>+13h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write
Size: 8-bits
NAME
SMI Status Register
2
Default = 0x00
on Vbat POR
DESCRIPTION
This register is used to read the status of the SMI inputs.
Bit[0] MINT: Mouse Interrupt. Cleared at source.
Bit[1] KINT: Keyboard Interrupt. Cleared at source.
Bit[2] IRINT: This bit is set by a transition on the IR pin (RXD2 or IRRX2 as
selected by Bit 6 of Configuration Register 0xF1 in Logical Device 5, i.e.,
after the MUX). Cleared by a read of this register.
Bit[3] BINT: Cleared by a read of this register.
Bit[4] P12: 8042 P1.2. Cleared at source
Bits[5:6] Reserved
Bit[7] SLP_EN_SMI. The SLP_EN SMI status bit. Cleared by a read of this
register. (See Sleep Enable Config Reg.)
0=no SMI due to setting SLP_EN bit
1=SMI generated due to setting SLP_EN bit.
163
SMI Enable Register 1 (SMI_EN1)
Register Location: < PM1_BLK >+14h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write
Size: 8-bits
NAME
SMI Enable Register
1
Default = 0x00
on Vbat POR
DESCRIPTION
This register is used to enable the different interrupt sources onto the group
nSMI output.
1=Enable
0=Disable
Bit[0] EN_RING
Note: the PME status bit for RING is used as the SMI status bit for RING
(see PME Status Register).
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
164
SMI Enable Register 2 (SMI_EN2)
Register Location: < PM1_BLK >+15h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write
Size: 8-bits
NAME
SMI Enable
Register 2
Default = 0x00
on Vbat POR
DESCRIPTION
This register is used to enable the different interrupt sources onto the group
nSMI output, and the group nSMI output onto the nSMI GPI/O pin.
Unless otherwise noted,
1=Enable
0=Disable
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_CIR
Note: the PME status bit for CIR is used as the SMI status bit for CIR (see
PME Status Register).
Bit[6] EN_SMI_PME: Enable the group nSMI output into the PME interface
logic.
0= Group SMI output does not go to PME interface logic
1= Enable group SMI output to PME interface logic
Bit[7] EN_SMI: Enable the group nSMI output onto the nSMI pin or Serial
IRQ frame (IRQ2).
0=SMI pin floats
1=Enable group nSMI output onto nSMI pin or serial IRQ frame
Note: the selection of either the nSMI pin or serial IRQ frame is done via bit
7 of the IRQ Mux Control Register (0xC0 in Logical Device 8).
165
function is selected for the GPIO pin, then the
bits that control input/output, polarity and open
collector/push-pull have no effect on the function
of the pin. However, the polarity bit does affect
the value of the GP bit (i.e., register GP1, bit 2
for GP12).
EITHER EDGE TRIGGERED INTERRUPTS
Four GPIO pins are implemented that allow an
interrupt to be generated on both a high-to-low
and a low-to-high edge transition, instead of one
or the other as selected by the polarity bit.
An interrupt occurs if the status bit is set and the
interrupt is enabled. The status bits indicate
which of the EETI interrupts transitioned. These
status bits are located in the MSC_STS register.
The status is valid whether or not the interrupt is
enabled and whether or not the EETI function is
selected for the pin.
The either edge triggered interrupts function as
follows: Selecting the Either Edge Triggered
Interrupt (EETI) function for these GPIO pins is
applicable when the combined interrupt is
enabled for the GPIO pin (GPINT1 for GP10GP17, and GPINT2 for GP50-GP54 and GP60GP67). Otherwise, selection of the EETI function
will produce no function for the pin. If the EETI
Miscellaneous Status Register
The MSC_STS register is implemented as follows to hold the status bits of these four GPIOs.
Miscellaneous Status Register (PM1_STS)
Register Location: <PM1_BLK>+16h System I/O Space
Default Value: 00h on Vbat POR
Attribute: Read/Write (Note 0)
Size: 8-bits
0
BIT
NAME
EETI1_STS
1
EETI2_STS
2
EETI3_STS
3
EETI4_STS
4
VTRPOR_STS
5-7
Reserved
DEFINITION
Either Edge Triggered Interrupt Input 1 Status. This bit is set when
an edge occurs on the GP11 pin. This bit is cleared by writing a 1 to
this bit position (writing a 0 has no effect).
Either Edge Triggered Interrupt Input 2 Status. This bit is set when
an edge occurs on the GP12 pin. This bit is cleared by writing a 1 to
this bit position (writing a 0 has no effect).
Either Edge Triggered Interrupt Input 3 Status. This bit is set when
an edge occurs on the GP53 pin. This bit is cleared by writing a 1 to
this bit position (writing a 0 has no effect).
Either Edge Triggered Interrupt Input 4 Status. This bit is set when
an edge occurs on the GP54 pin. This bit is cleared by writing a 1 to
this bit position (writing a 0 has no effect).
This bit is set upon VTR POR. This bit is cleared by writing a 1 to
this bit position (writing a 0 has no effect). Additionally, when the
system turns on (nPowerOn active low) due to a VTR POR, then an
SCI is generated.
Reserved. This bit always returns zero.
SMI/PME/SCI Logic
The logic for the SMI, PME and SCI signals is shown in the figures that follow.
166
FIGURE 5 - PME/SCI LOGIC
PME_EN
Registers
PME_STS
Registers
PME_EN1 Register
PME_STS1 Register
CIR
EN_CIR
RI2
EN_RI2
RI1
EN_RI1
nPME
MUX
00
pin
01
10
Bit[6]
Bits[6:5]
of IRQ
Mux Control
Register
KBD
EN_KBD
nPME
nSCI
IRQ9
MOUSE
EN_MOUSE
RING
EN_RING
RTC
EN_RTC
PME_STS
DEV_INT
EN_DEVINT
Bit[5]
PME_EN2 Register
From
SMI/PME
Device
Interrupt
Block
PME_STS2 Register
GP10
EN_GP10
PME_EN
EN_GP11
nSCI
EN_GP12
GPE_STS
Register
on IRQx
pin
EN_GP13
EN_GP14
GPE_EN
Register SCI_STS1
GPE_STS.0
nSCI
EN_GP16
GP12
GP13
GP14
GP15
GP16
GP17
EN_GP17
SCI_EN1
GPE_EN.0
on Serial
IRQx
EN_GP15
GP11
SCI_EN
PM1_BLK
PWRBTN_STS
Bit[2] of IRQ Mux
Control Register
PWRBTN_EN
RTC_STS
RTC_EN
nPowerOn
Key to Symbols
WAK_STS
Enable bit
Sticky Status bit: Cleared by software
writing a ‘1’ to its bit location
WAK_CTRL
167
FIGURE 6 - SMI/PME LOGIC
SMI_EN
Registers
SMI_EN1 Register
to nPME
Interface
SYSTEM
ELEMENTS EN_SMI_PME
Logic
Bit 6 of
SMI_EN2 Register
Primary Configuration Address Decoder
After a hard reset (RESET_DRV pin asserted) or
Vcc Power On Reset the FDC37B78x 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 FDC37B78x into
Configuration Mode.
The BIOS uses these
PORT NAME
SMI_STS1 Register
EN_RING
PINT
EN_GPINT1
WDT
EVENT
RING Bit, PME_STS1 Register
nRING
configuration
ports to
initialize thePINT
logical devices
EN_PINT
U2INT
U2INT
EN_U2INT
U1INT
at POST. The INDEX and DATAU1INT
ports are only
EN_U1INT
FINT
FINT Configuration
valid EN_FINT
when the FDC37B78x
is in
GPINT2
GPINT2
Mode.EN_GPINT2
GPINT1
GPINT1
CONFIGURATION
The Configuration of the FDC37B78x is very
flexible and is based on the configuration
architecture implemented inGroup
typical Plug-and-Play
SMI
components.
The FDC37B78x is designed for
nSMI
out to pin applications in which the resources
motherboard
EN_SMI
Serial
requiredorIRQ2
by their components
Bit 7 are known. With its
of SMI_EN2
flexible resource allocation
architecture, the
Register
FDC37B78x allows the BIOS to assign resources
at POST.
DEV_INT
SMI_STS
Registers
WDT
EN_WDT
The SYSOPT pin is latched on the falling edge of
SMI_STS2 Register
SMI_EN2 Register
the RESET_DRV orMINT
on Vcc Power
On Reset to
MINT
EN_MINT
KINT
determine
the configuration
register's
base
KINT
EN_KINT
IRINT
IRINT to select the
address.
The SYSOPT
pin
is
used
EN_IRINT
BINT
BINT
CONFIG
EN_BINTPORT's I/O
P12 address at power-up. Once
P12
EN_P12
CIR
Bit,
PME_STS1
Register
powered up the configuration portCIR base
address
EN_CIR
SLP_EN_SMI
can be changed through configuration
registers
SLP_EN
CR26 and CR27. The SYSOPT pin is a
SLP_CTRL
hardware
configuration pin which is shared
Bit 0 of the Sleep Enable
with the
nRTS1 signal
pin 115. During reset
Key toon
Symbols
Configuration
Register
0xF0 of Logical Device A.
this pin is a weak active
low
Enable
bit signal which sinks
30µA. Note: All I/O addresses
are qualified with
Interrupt Status bit: Cleared at
source
AEN.
Interrupt Status bit: Cleared by
a read of register
Sticky Status bit: Cleared by a
write of ‘1’ to this bit
The INDEX and DATA ports are effective only
when the chip is in the Configuration State.
SYSOPT= 0
(Pull-down resistor)
Refer to Note 1
SYSOPT= 1
(10K Pull-up resistor)
TYPE
CONFIG PORT (Note 2)
0x03F0
0x0370
Write
INDEX PORT (Note 2)
0x03F0
0x0370
Read/Write
DATA PORT
INDEX PORT + 1
Read/Write
Note 1:If using TTL RS232 drivers use 1K pull-down. If using CMOS RS232 drivers use 10K pull-down.
Note 2: The configuration port base address can be relocated through CR26 and CR27.
168
Entering the Configuration State
Configuration Mode
The device enters the Configuration State when
the following Config Key is successfully written to
the CONFIG PORT.
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.
Config Key = < 0x55>
When in configuration mode, all logical devices
function properly.
Entering and exiting
configuration mode has no effect on the devices.
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.
Exiting the Configuration State
The device exits the Configuration State when the
following Config Key is successfully written to the
CONFIG PORT.
Config Key = < 0xAA>
Note: if accessing the Global Configuration
Registers, step (a) is not required.
CONFIGURATION SEQUENCE
To program the configuration registers, the
following sequence must be followed:
1. Enter Configuration Mode
2. Configure the Configuration Registers
3. Exit Configuration Mode.
Exit Configuration Mode
To exit the Configuration State the system writes
0xAA to the CONFIG PORT. The chip returns to
the RUN State.
Enter Configuration Mode
Note: Only two states are defined (Run and
Configuration). In the Run State the chip will
always be ready to enter the Configuration State.
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 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).
149
Programming Example
The following is an example of a configuration program in Intel 8086 assembly language.
;----------------------------.
; ENTER CONFIGURATION MODE
|
;----------------------------'
MOV DX,3F0H
MOV AX,055H
CLI; disable interrupts
OUT DX,AL
STI; enable interrupts
;-------------------------------.
; 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
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)
171
CONFIGURATION REGISTERS
INDEX
TYPE
HARD
RESET
Vbat
SOFT
Vcc POR
Vtr POR
POR
RESET
GLOBAL CONFIGURATION REGISTERS
CONFIGURATION
REGISTER
0x02
W
0x00
0x00
0x00
-
-
Config Control
0x03
R/W
0x03
0x03
0x03
-
-
Index Address
0x07
R/W
0x00
0x00
0x00
-
0x00
Logical Device Number
0x20
R
0x44
0x44
0x44
-
0x44
Device ID - hard wired
0x21
R
0x00
0x00
0x00
-
0x00
Device Rev - hard wired
0x22
R/W
0x23
R/W
0x24
R/W
0x26
R/W
0x27
R/W
(Note 0)
0x00
0x00
(Note 0)
0x00
(Note 0)
0x00
(Note
-
0x00
0)
Power Control
0x00
0x00
-
-
Power Mgmt
0x04
0x04
0x04
-
-
OSC
Sysopt=0:
0xF0
Sysopt=1:
0x70
Sysopt=0:
0x03
Sysopt=1:
0x03
0x00
-
-
-
Configuration Port
Address Byte 0
-
-
-
Configuration Port
Address Byte 1
0x28
R/W
Sysopt=0:
0xF0
Sysopt=1:
0x70
Sysopt=0:
0x03
Sysopt=1:
0x03
0x00
-
-
0x00
0x2B
R/W
-
0x00
0x00
-
-
TEST 4
0x2C
R/W
-
0x00
0x00
-
-
TEST 5
0x2D
R/W
-
0x00
0x00
-
-
TEST 1
0x2E
R/W
-
0x00
0x00
-
-
TEST 2
0x2F
R/W
-
0x00
0x00
-
-
TEST 3
Clock Mask Register
LOGICAL DEVICE 0 CONFIGURATION REGISTERS (FDD)
0x30
R/W
0x00
0x00
0x00
-
0x00
Activate
0x60,
0x61
R/W
0x03,
0xF0
0x03,
0xF0
0x03,
0xF0
-
0x03,
0xF0
Primary Base I/O
Address
0x70
R/W
0x06
0x06
0x06
-
0x06
Primary Interrupt Select
0x74
R/W
0x02
0x02
0x02
-
0x02
DMA Channel Select
0xF0
R/W
0x0E
0x0E
0x0E
-
-
FDD Mode Register
0xF1
R/W
0x00
0x00
0x00
-
-
FDD Option Register
0xF2
R/W
0xFF
0xFF
0xFF
-
-
FDD Type Register
0xF4
R/W
0x00
0x00
0x00
-
-
FDD0
0xF5
R/W
0x00
0x00
0x00
-
-
FDD1
LOGICAL DEVICE 1 CONFIGURATION REGISTERS (Reserved)
LOGICAL DEVICE 2 CONFIGURATION REGISTERS (Reserved)
LOGICAL DEVICE 3 CONFIGURATION REGISTERS (Parallel Port)
172
HARD
RESET
0x00
Vcc POR
0x00
Vtr POR
0x00
R/W
0x00,
0x00
0x00,
0x00
0x70
R/W
0x00
0x74
R/W
0x04
0xF0
R/W
0xF1
R/W
0x30
R/W
0x00
0x00
0x00
-
0x00
Activate
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
0x00,
0x00
-
0x00,
0x00
Primary Base I/O
Address
Primary Interrupt Select
INDEX
0x30
TYPE
R/W
0x60,
0x61
Vbat
POR
-
SOFT
RESET
0x00
CONFIGURATION
REGISTER
Activate
0x00,
0x00
-
0x00,
0x00
Primary Base I/O
Address
0x00
0x00
-
0x00
Primary Interrupt Select
0x04
0x04
-
0x04
DMA Channel Select
0x3C
0x3C
0x3C
-
-
Parallel Port Mode
Register
0x00
0x00
0x00
-
-
Parallel Port Mode
Register 2
LOGICAL DEVICE 4 CONFIGURATION REGISTERS (Serial Port 1)
0x70
R/W
0x00
0x00
0x00
-
0x00
0xF0
R/W
0x00
0x00
0x00
-
-
0x30
R/W
-
-
0x00
-
-
0x60,
0x61
R/W
0x00,
0x00
0x00,
0x00
0x00,
0x00
-
0x00,
0x00
Primary Base I/O
Address
0x62,
0x63
R/W
0x00, 0x00
0x00,
0x00
0x00,
0x00
-
0x00,
0x00
CIR Base I/O Address
0x70
R/W
0x00
0x00
0x00
-
0x00
Primary Interrupt Select
Serial Port 1 Mode
Register
LOGICAL DEVICE 5 CONFIGURATION REGISTERS (Serial Port 2)
Activate
0x74
R/W
0x04
0x04
0x04
-
0x04
0xF0
R/W
0x00
0x00
0x00
-
-
Serial Port 2 Mode
Register
DMA Channel Select
0xF1
R/W
0x02
0x02
0x02
-
-
IR Options Register
0xF2
R/W
0x03
0x03
0x03
-
-
IR Half Duplex Timeout
LOGICAL DEVICE 6 CONFIGURATION REGISTERS (RTC)
0x30
R/W
0x00
0x00
0x00
-
0x00
Activate
0x62,
0x63
R/W
0x00,
0x70
0x00,
0x70
0x00,
0x70
-
0x00,
0x70
Secondary Base
Address for RTC Bank 1
0x70
R/W
0x00
0x00
0x00
-
0x00
Primary Interrupt Select
0xF0
R/W
0x00
0x00
n/a
-
n/a
Real Time Clock Mode
Register
LOGICAL DEVICE 7 CONFIGURATION REGISTERS (Keyboard)
0x30
R/W
0x00
0x00
0x00
-
0x00
Activate
0x70
R/W
0x00
0x00
0x00
-
0x00
Primary Interrupt Select
0x72
R/W
0x00
0x00
0x00
-
0x00
Second Interrupt Select
0xF0
R/W
0x00
0x00
0x00
-
-
KRESET and GateA20
Select
173
INDEX
TYPE
HARD
Vbat
SOFT
RESET
Vcc POR
Vtr POR
POR
RESET
LOGICAL DEVICE 8 CONFIGURATION REGISTERS (Aux I/O)
CONFIGURATION
REGISTER
0x30
R/W
0x00
0x00
0x00
-
0x00
0xB0
R/W
-
-
-
0x00
-
Soft Power Enable
3
Register 1
Activate
0xB1
R/W
-
-
-
0x80
-
Soft Power Enable
3
Register 2
0xB2
R/W
-
-
-
0x00
-
Soft Power Status
3
Register 1
0xB3
R/W
-
-
-
0x00
-
Soft Power Status
3
Register 2
0xB8
R/W
-
-
0x00
-
-
Delay 2 Time Set
Register
0xC0
R/W
-
-
-
0x00
-
IRQ Mux Control
0xC1
R/W
0x01
0x01
-
-
-
Force Disk Change
0xC2
R
-
-
-
-
-
Floppy Data Rate Select
Shadow
0xC3
R
-
-
-
-
-
UART1 FIFO Control
Shadow
0xC4
R
-
-
-
-
-
UART2 FIFO Control
Shadow
0xC5
R/W
0x00
0x00
-
-
-
FDC Force Write Protect
0xC6
R/W
-
-
-
0x00
-
Ring Filter Select
0xC8
R/W
-
-
-
0x01
-
GP50
3
0xCA
R/W
-
-
-
0x09
-
GP52
3
0xCB
R/W
-
-
-
0x01
-
GP53
3
0xCC
R/W
-
-
-
0x01
-
GP54
3
0xD0
R/W
-
-
-
0x01
-
GP60
3
0xD1
R/W
-
-
-
0x01
-
GP61
3
0xD2
R/W
-
-
-
0x01
-
GP62
3
0xD3
R/W
-
-
-
0x01
-
GP63
3
0xD4
R/W
-
-
-
0x01
-
GP64
3
0xD5
R/W
-
-
-
0x01
-
GP65
3
0xD6
R/W
-
-
-
0x01
-
GP66
3
0xD7
R/W
-
-
-
0x01
-
GP67
3
0xE0
R/W
-
-
-
0x01
-
GP10
3
0xE1
R/W
-
-
-
0x01
-
GP11
3
0xE2
R/W
-
-
-
0x01
-
GP12
3
0xE3
R/W
-
-
-
0x01
-
GP13
3
0xE4
R/W
-
-
-
0x01
-
GP14
3
174
3
3
INDEX
0xE5
TYPE
R/W
HARD
RESET
-
Vcc POR
-
Vtr POR
-
Vbat
POR
0x00
SOFT
RESET
-
CONFIGURATION
REGISTER
3
GP15
0xE6
R/W
-
-
-
0x01
-
GP16
3
0xE7
R/W
-
-
-
0x01
-
GP17
3
0xEF
R/W
-
-
-
0x00
-
GP_INT2
3
0xF0
R/W
-
-
-
0x00
-
GP_INT1
3
0xF1
R/W
0x00
0x00
0x00
-
-
WDT_UNITS
0xF2
R/W
0x00
0x00
0x00
-
-
WDT_VAL
0xF3
R/W
0x00
0x00
0x00
-
-
WDT_CFG
0xF4
(1)
R/W
0x00
0x00
0x00
-
-
WDT_CTRL
0xF6
R/W
-
-
-
0x00
-
GP1
3
0xF9
R/W
-
-
-
0x00
-
GP5
3
0xFA
R/W
-
-
-
0x00
-
GP6
3
LOGICAL DEVICE A CONFIGURATION REGISTERS (ACPI)
4
0x30
R/W
0x00
0x00
0x00
-
0x00
Activate
0x60,
(2)
0x61
R/W
0x00,
0x00
0x00,
0x00
0x00,
0x00
-
0x00,
0x00
Primary Base I/O
Address
PM1_BLK
0x70
R/W
-
-
-
0x00
-
Primary Interrupt Select
0xF0
R/W
-
-
-
0x00
-
Sleep/Wake
3
Configuration
3
Notes
0) CR22 Bit 5 is reset on Vtr POR only
1) This register contains some bits which are read or write only.
2) Register 60 is the high byte; 61 is the low byte. For example to set the primary base address to
1234h, write 12h into 60, and 34h into 61.
3) These configuration registers are powered by Vtr and battery backed up.
4) The Activate bit for Logical Device A does not effect the generation of an interrupt (SCI).
175
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. 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.
REGISTER
ADDRESS
TABLE 71 - CHIP LEVEL REGISTERS
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, WDT_CTRL, GP5, GP6, Soft Power
Enable and Status Register access when not in
configuration mode
= 0 Disable GP1, WDT_CTRL, GP5, GP6, Soft Power
Enable and Status Register access when not in
configuration mode (Default)
Bits [6:2]
Reserved - Writes are ignored, reads return 0.
Default = 0x00
on Vcc POR or
Reset_Drv
Index Address
Reserved - Writes are ignored, reads return 0.
Default = 0x03
on Vcc POR or
Reset_Drv
C
Bits[1:0]
Sets GP1 etc. selection register used when in Run
mode (not in Configuration Mode).
= 11 0xEA (Default)
= 10 0xE4
= 01 0xE2
= 00 0xE0
0x04 - 0x06
Logical Device #
Default = 0x00
on Vcc POR or
Reset_Drv
Card Level
Reserved
0x07 R/W
0x08 - 0x1F
Reserved - Writes are ignored, reads return 0.
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.
Reserved - Writes are ignored, reads return 0.
Chip Level, SMSC Defined
176
C
REGISTER
Device ID
ADDRESS
DESCRIPTION
STATE
0x20 R
A read only register which provides
identification. Bits[7:0] = 0x44 when read
device
C
0x21 R
A read only register which provides device revision
information. Bits[7:0] = 0x00 when read
C
0x22 R/W
Bit[0] FDC Power
Bit[1] Reserved
Bit[2] Reserved
Bit[3] Parallel Port Power
Bit[4] Serial Port 1 Power
Bit[5] Serial Port 2 Power
Bit[6] Reserved
Bit[7] Reserved
= 0 Power off or disabled
= 1 Power on or enabled
C
0x23 R/W
Bit[0] FDC
Bit[1] Reserved
Bit[2] Reserved
Bit[3] Parallel Port
Bit[4] Serial Port 1
Bit[5] Serial Port 2
Bit[6] Reserved (read as 0)
Bit[7] Reserved (read as 0)
= 0 Intelligent Pwr Mgmt off
= 1 Intelligent Pwr Mgmt on
C
0x24 R/W
Bit[0] Reserved
Bit [1] PLL Control
= 0 PLL is on (backward Compatible)
= 1 PLL is off
Bits[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.
C
Hard wired
= 0x44
Device Rev
Hard wired
= 0x00
PowerControl
Default = 0x00.
on Vcc POR or
Reset_Drv
hardware signal.
Power Mgmt
Default = 0x00.
on Vcc POR or
Reset_Drv
hardware signal
OSC
Default = 0x04,
on Vcc POR or
Reset_Drv
hardware signal.
Bit [6:4] Reserved, set to zero
Bit[7] IRQ8 Polarity
= 0 IRQ8 is active high
= 1 IRQ8 is active low
Chip Level
Vendor Defined
0x25
Reserved - Writes are ignored, reads return 0.
177
REGISTER
Configuration
Address Byte 0
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
Chip Level
Vendor Defined
ADDRESS
0x26
0x27
DESCRIPTION
STATE
Bit[7:1] Configuration Address Bits [7:1]
Bit[0] = 0
See Note 1 Below
C
Bit[7:0] Configuration Address Bits [15:8]
C
See Note 1 Below
0x28 -0x2A
Reserved - Writes are ignored, reads return 0.
TEST 4
0x2B R/W
Test Modes: Reserved for SMSC. Users should not
write to this register, may produce undesired results.
C
TEST 5
0x2C R/W
Test Modes: Reserved for SMSC. Users should not
write to this register, may produce undesired results.
C
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 or
Reset_Drv
hardware signal.
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 (Note: 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.
Note: the default configuration address is either 3F0 or 370, as specified by the SYSOPT pin.
This change affects SMSC Mode only.
178
Logical Device Configuration/Control Registers [0x30-0xFF]
Used to access the registers that are assigned to each logical unit. This chip supports eight logical units
and has eight sets of logical device registers. The eight logical devices are Floppy, Parallel Port, Serial
Port 1 and Serial Port 2, Real Time Clock, Keyboard Controller, Auxiliary I/O and ACPI. A separate set
(bank) of control and configuration register exists for each logical device and is selected with the Logical
Device # Register (0x07).
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:
Logical Device Registers
TABLE 72 - CHIP LEVEL REGISTERS
LOGICAL DEVICE
REGISTER
Activate
Note1
ADDRESS
DESCRIPTION
STATE
(0x30)
Bits[7:1] Reserved, set to zero.
Bit[0]
= 1 Activates the logical device currently selected
through the Logical Device # register.
= 0 Logical device currently selected is inactive
C
Default = 0x00
on Vcc POR or
Reset_Drv Note 2
Logical Device
Control
(0x31-0x37)
Reserved - Writes are ignored, reads return 0.
C
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]
Interrupt Select
(0x70,072)
Defaults :
0x70 = 0x00,
on Vcc POR or
Reset_Drv
Unused registers will ignore writes and return zero
when read.
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).
0x72 = 0x00,
on Vcc POR or
Reset_Drv
179
C
LOGICAL DEVICE
REGISTER
ADDRESS
DESCRIPTION
(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 zero when read. Refer to DMA
Channel Configuration.
(0x76-0xA8)
Reserved - not implemented.
These register
locations ignore writes and return zero when read.
Logical Device
(0xA9-0xDF)
Reserved - not implemented.
These register
locations ignore writes and return zero when read.
C
Logical Device
Config.
(0xE0-0xFE)
Reserved - Vendor Defined (see SMSC defined
Logical Device Configuration Registers)
C
Reserved
C
DMA Channel Select
Default = 0x04
on Vcc POR or
Reset_Drv
32-Bit Memory
Space Configuration
Reserved
0xFF
STATE
C
Note 1: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.
Note: 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.
Note 2. The activate bit for Logical Device 5 (Serial Port 2) is reset on Vtr POR only.
180
I/O Base Address Configuration Register
LOGICAL
DEVICE
NUMBER
0x00
TABLE 73 - I/O BASE ADDRESS CONFIGURATION REGISTER DESCRIPTION
BASE I/O
FIXED
RANGE
LOGICAL REGISTER
INDEX
BASE OFFSETS
(NOTE3)
DEVICE
+0 : SRA
FDC
0x60,0x61
[0x100:0x0FF8]
+1 : SRB
(Note 4)
ON 8 BYTE BOUNDARIES +2 : DOR
+3 : TSR
+4 : MSR/DSR
+5 : FIFO
+7 : DIR/CCR
0x03
Parallel
Port
0x60,0x61
[0x100:0x0FFC]
ON 4 BYTE BOUNDARIES
(EPP Not supported)
or
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
(all modes supported,
EPP is only available when
the base address is on an 8byte boundary)
0x04
Serial Port
1
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
0x05
Serial Port
2
0x60,0x61
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
181
+0 : Data|ecpAfifo
+1 : Status
+2 : Control
+3 : EPP Address
+4 : EPP Data 0
+5 : EPP Data 1
+6 : EPP Data 2
+7 : EPP Data 3
+400h : cfifo|ecpDfifo|tfifo
|cnfgA
+401h : cnfgB
+402h : ecr
+0 : RB/TB|LSB div
+1 : IER|MSB div
+2 : IIR/FCR
+3 : LCR
+4 : MSR
+5 : LSR
+6 : MSR
+7 : SCR
+0 : RB/TB|LSB div
+1 : IER|MSB div
+2 : IIR/FCR
+3 : LCR
+4 : MSR
+5 : LSR
+6 : MSR
+7 : SCR
LOGICAL
DEVICE
NUMBER
LOGICAL
DEVICE
REGISTER
INDEX
0x62,0x63
0x06
RTC
BASE I/O
RANGE
(NOTE3)
[0x100:0x0FF8]
ON 8 BYTE BOUNDARIES
n/a
Not Relocatable
Fixed Base Address: 70,71
0x62, 0x63
[0x00:0xFFE]
ON 2 BYTE BOUNDARIES
Not Relocatable
Fixed Base Address: 60,64
0x07
KYBD
n/a
0x0A
ACPI
0x60,0x61
FIXED
BASE OFFSETS
+0 : CIR Registers
+1 : CIR Registers
+2 : CIR Registers
+3 : CIR Registers
+4 : CIR Registers
+5 : CIR Registers
+6 : CIR Registers
+7 : CIR Registers
+0: Index Register
+1: Data Register
+0: Index Register
+1: Data Register
+0 : Data Register
+4 : Command/Status
Reg.
[0x00:0x0FE7]
ON 24 BYTE BOUNDARIES
Note 3:This chip uses ISA address bits [A11:A0] to decode the base address of each of its logical devices.
182
Interrupt Select Configuration Register
TABLE 74 - INTERRUPT SELECT CONFIGURATION REGISTER DESCRIPTION
NAME
REG INDEX
DEFINITION
STATE
Interrupt
Request Level
Select 0
Default = 0x00
on Vcc POR or
Reset_Drv
Note:
0x70 (R/W)
Bits[3:0] selects which interrupt level is used for
Interrupt 0.
0x00=no interrupt selected.
0x01=IRQ1
0x02=IRQ2
•
•
•
0x0E=IRQ14
0x0F=IRQ15
Note: All interrupts are edge high (except ECP/EPP)
C
It is the responsibility of the software to ensure that two IRQ’s are not set to the same IRQ
number.
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.
183
DMA Channel Select Configuration Register
TABLE 75 - DMA CHANNEL SELECT CONFIGURATION REGISTER DESCRIPTION
NAME
REG INDEX
DEFINITION
STATE
DMA Channel
Select
Default = 0x04
on Vcc POR or
Reset_Drv
0x74 (R/W)
Bits[2:0] select the DMA Channel.
0x00=DMA0
0x01=DMA1
0x02=DMA2
0x03=DMA3
0x04-0x07= No DMA active
C
Note: 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.
for the UART 2 logical device, by setting the DMA Enable bit. Refer to the IRCC specification.
Note:DMAREQ pins must tri-state if not used/selected by any Logical Device. Refer to Note A.
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).
2)
FDC: For the following cases, the IRQ and DACK used by the FDC are disabled (high impedance).
Will not respond to the DREQ.
a) Digital Output Register (Base+2) bit D3 (DMAEN) set to "0".
b) The FDC is in power down (disabled).
3)
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.
4)
Parallel Port: SPP and EPP modes: Control Port (Base+2) bit D4 (IRQE) set to "0", IRQ is disabled
(high impedance).
184
a) ECP Mode:
i) (DMA) dmaEn from ecr register. See table.
ii) IRQ - See table.
MODE
(FROM ECR REGISTER)
5)
IRQ PIN
CONTROLLED BY
PDREQ PIN
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
Real Time Clock and Keyboard Controller: Refer to the RTC and KBD section of this spec.
SMSC Defined Logical Device Configuration Registers
The SMSC Specific Logical Device Configuration Registers reset to their default values only on hard resets
generated by Vcc POR or VTR POR or VBAT POR (as shown) or the RESET_DRV signal.
185
These registers are not affected by soft resets.
TABLE 76 - FLOPPY DISK CONTROLLER, LOGICAL DEVICE 0 [LOGICAL DEVICE NUMBER = 0X00]
NAME
REG INDEX
DEFINITION
STATE
FDD Mode
Register
0xF0 R/W
Default = 0x0E
on Vcc POR or
Reset_Drv
Bit[0] Floppy Mode
= 0Normal 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.
Bits[5] Reserved, set to zero.
C
Bit [6] Output Type Control:
0= FDC outputs are OD24 open drain (default)
1= FDC outputs are O24 push-pull.
Bit [7] FDC output Control:
0= FDC outputs active (default)
1= FDC outputs tristated
Note: these bits do not affect the parallel port FDC pins.
FDD Option
Register
0xF1 R/W
Bits[1:0] Reserved, set to zero
Bits[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[5:4] Reserved, set to zero
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
0xF2 R/W
Bits[1:0]
Bits[3:2]
Bits[5:4]
type)
Bits[7:6]
type)
C
Default = 0x00
on Vcc POR or
Reset_Drv
FDD Type
Register
Default = 0xFF
on Vcc POR or
Reset_Drv
Floppy Drive A Type
Floppy Drive B Type
Reserved (could be used to store Floppy Drive C
Reserved (could be used to store Floppy Drive D
Note: The FDC37B78x supports two floppy drives
0xF3 R
Reserved, Read as 0 (read only)
186
C
NAME
FDD0
REG INDEX
STATE
0xF4 R/W
Bits[1:0] Drive Type Select: DT1, DT0
Bits[2] Read as 0 (read only)
Bits[4:3] Data Rate Table Select: DRT1, DRT0
Bits[5] Read as 0 (read only)
Bits[6] Precompensation Disable PTS
=0 Use Precompensation
=1 No Precompensation
Bits[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
187
Parallel Port, Logical Device 3
TABLE 77 - PARALLEL PORT, LOGICAL DEVICE 3 [LOGICAL DEVICE NUMBER = 0X03]
NAME
REG INDEX
DEFINITION
STATE
PP Mode
Register
0xF0 R/W
Default =
0x3C
on Vcc POR
or
Reset_Drv
Bits[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.
PP Mode
Register 2
Default =
0x00
on Vcc POR
or
Reset_Drv
0xF1 R/W
Bits[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
Bits[7:2] Reserved. Set to zero.
188
C
Serial Port 1, Logical Device 4
TABLE 78 - SERIAL PORT 1, LOGICAL DEVICE 4 [LOGICAL DEVICE NUMBER = 0X04]
NAME
REG INDEX
DEFINITION
STATE
Serial Port 1
Mode Register
Default = 0x00
on Vcc POR or
Reset_Drv
0xF0 R/W
Bit[0] MIDI Mode
= 0 MIDI support disabled (default)
= 1 MIDI support enabled
C
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 1 below.
Note 1: To properly share and 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.
Note: If both UARTs are configured to use different IRQ pins and the share IRQ bit is set, then both of
the UART IRQ pins will assert when either UART generates an interrupt.
189
TABLE 79 - UART INTERRUPT OPERATION
UART2
IRQ PINS
UART2
UART2
Share
UART1
UART2
IRQ
OUT2 bit
IRQ State
Pin State
Pin State
Bit
This part of the table is based on the assumption that both UARTS have selected different IRQ
pins
0
Z
0
Z
0
Z
Z
1
asserted
0
Z
0
1
Z
1
de-asserted
0
Z
0
0
Z
0
Z
1
asserted
0
Z
1
0
Z
1
de-asserted
0
Z
0
1
asserted
1
asserted
0
1
1
1
asserted
1
de-asserted
0
1
0
1
de-asserted
1
asserted
0
0
1
1
de-asserted
1
de-asserted
0
0
0
0
Z
0
Z
1
Z
Z
1
asserted
0
Z
1
1
1
1
de-asserted
0
Z
1
0
0
0
Z
1
asserted
1
1
1
0
Z
1
de-asserted
1
0
0
1
asserted
1
asserted
1
1
1
1
asserted
1
de-asserted
1
1
1
1
de-asserted
1
asserted
1
1
1
1
de-asserted
1
de-asserted
1
0
0
It is the responsibility of the software to ensure that two IRQ’s are not set to the same IRQ
number. However, if they are set to the same number then no damage to the chip will result.
UART1
UART1
UART1
OUT2 bit
IRQ State
190
Serial Port 2, Logical Device 5
TABLE 80 - SERIAL PORT 2, LOGICAL DEVICE 5 [LOGICAL DEVICE NUMBER = 0X05]
NAME
REG INDEX
DEFINITION
STATE
Serial Port 2
Mode Register
0xF0 R/W
Bit[0] MIDI Mode
= 0MIDI support disabled (default)
= 1MIDI support enabled
Bit[1] High Speed
= 0High Speed disabled(default)
= 1High Speed enabled
Bit[7:2] Reserved, set to zero
C
0xF1 R/W
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
Bits[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 TXD2 and RXD2 (Default)
= 1Use alternate IRRX2 (pin 81) and IRTX2 (pin 82)
Bit[7] Reserved, write 0
C
Default = 0x00
on Vcc POR or
Reset_Drv
IR Option Register
Default = 0x02
on Vcc POR or
Reset_Drv
IR Half Duplex
Timeout
Default = 0x03
on Vcc POR or
Reset_Drv
(EN 1)
0xF2
Bits [7:0]
These bits set the half duplex time-out for the IR port.
This value is 0 to 10msec in 100usec increments.
0= blank during transmit/receive
1= blank during transmit/receive + 100usec
...
191
RTC, Logical Device 6
TABLE 81 - RTC, LOGICAL DEVICE 6 [LOGICAL DEVICE NUMBER = 0X06]
NAME
REG INDEX
DEFINITION
STATE
RTC Mode Register
Default = 0x00
on Vcc POR or
Reset_Drv
0xF0 R/W
Bit[0] = 1 : Lock CMOS RAM 00-1Fh in Bank 1
Bit[1] = 1 : Lock CMOS RAM 20-3Fh in Bank 1
Bit[2] = 1 : Lock CMOS RAM 40-5Fh in Bank 1
Bit[3] = 1 : Lock CMOS RAM 60-7Fh in Bank 1
C
Bits[5:4] RTC Bank Selection
=00 Bank 1 at Secondary Base Address, Bank 0 Off
(Default)
=01 Bank 0 at 70h and Bank 1 at Secondary Base
Address (Note 1)
=10 No Bank Selected
=11 Bank 0 at 70h, Bank 1 Off
Bit[7:6] Reserved
Note: Once set, bits[3:0] can not be cleared by a
write; bits[3:0] are cleared only on Vcc Power On
Reset or upon a Hard Reset.
Note 1: The secondary base address must be set to a value other than 70h prior to selecting this option.
192
KYBD, Logical Device 7
TABLE 82 - KYBD, LOGICAL DEVICE 7 [LOGICAL DEVICE NUMBER = 0X07]
NAME
REG INDEX
DEFINITION
STATE
KRST_GA20
0xF0
KRESET and GateA20 Select
R/W
Bit[7] Polarity Select for P12
= 0 P12 active low (default)
= 1 P12 active high
Bits[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
193
Auxiliary I/O, Logical Device 8
TABLE 83 - AUXILLIARY I/O, LOGICAL DEVICE 8 [LOGICAL DEVICE NUMBER = 0X08]
NAME
REG INDEX
DEFINITION
STATE
C
0xB0 R/W
The following bits are the enables for the wake-up
Soft Power Enable
function of the nPowerOn bit. When enabled,
Register 1
these bits allow their corresponding function to turn
on power to the system.
Default = 0x00
on Vbat 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
C
0xB1 R/W
The following bits are the enables for the wake-up
Soft Power Enable
function of the nPowerOn bit. When enabled,
Register 2
these bits allow their corresponding function to turn
on power to the system.
Default = 0x80
on Vbat POR
1 = ENABLED
0 = DISABLED
Bit[0] SP_RXD1: UART 1 Receive Data Pin
Bit[1] SP_RXD2: UART 2 Receive Data Pin
Bit[2] Reserved
Bit[3] RING Enable bit “RING_EN”
0=Disable.
1=Enable ring indicator on nRING pin as wakeup
function to activate nPowerOn.
Bit[4] Reserved
Bit[5] CIR Enable bit “CIR_EN”
0=Disable.
1=Enable CIR wakeup event to activate nPowerOn
Bit[6] Reserved
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.
194
NAME
Soft Power Status
Register 1
Default = 0x00
on Vbat POR
REG INDEX
0xB2 R/W
DEFINITION
The following bits are the status for the wake-up
function of the nPowerOn bit. These indicate which
of the enabled wakeup functions caused the power
up.
1 = Occured
0 = Did not occur since last cleared
The following signals are latched to detect and hold
the soft power event (Type 1) (Note 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) (Note 1)
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
195
STATE
C
NAME
Soft Power Status
Register 2
Default = 0x00
on Vbat POR
REG INDEX
0xB3 R/W
DEFINITION
The following bits are the status for the wake-up
function of the nPowerOn bit. These indicate
which of the enabled wakeup functions caused the
power up.
1 = Occured
0 = Did not occur since last cleared
The following signals are latched to detect and hold
the soft power event (Type 1) (Note 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[3] RING Status bit “RING_STS”; Latched, cleared
on read.
0= nRING input did not occur.
1= Ring indicator input occurred on the nRING pin
and, if enabled, caused the wakeup (activated
nPowerOn)
Bit[4] Reserved
Bit[5] CIR Status bit “CIR_STS”; latched, cleared
on read.
0= CIR wakeup event did not occur.
1= CIR wakeup event occurred and, if enabled,
caused the wakeup (activated nPowerOn).
The following signal is latched to detect and hold the
soft power event (Type 3) (Note 1) 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
Bits[7:6] Reserved
196
STATE
C
NAME
Delay 2 Time Set
Register
Default = 0x00
on VTR POR
REG INDEX
0xB8 R/W
DEFINITION
This register is used to set Delay 2 (for Soft Power
Management) to a value from 500 msec to 32 sec.
The default value is 500msec. Engineering Note:
this delay is started if OFF_EN is enabled and
OFF_DLY was set and a Button Input comes in.
Bits[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
Bits[7:6] Reserved
197
STATE
C
NAME
IRQ Mux Control
Register
Default = 0x00
on Vbat POR
REG INDEX
DEFINITION
0XC0 R/W
This register is used to configure the IRQs, including PME,
SCI and SMI.
Bit[0] Serial/Parallel IRQs
0=Serial IRQs are used
1=Parallel IRQS are used
Note 1: This bit does not control the RTC IRQ, SCI or SMI
interrupts. See bits 1,2,7 of this register.
Note 2: If set, the BIOS buffer is disabled. Also, the
SER_IRQ and PCI_CLK pins are disabled, and these pins
function as IRQ15 and IRQ14, respectively.
Note 3: Select IRQ9 below. Select RTC IRQ and SCI
below. Select nSMI through the SMI register.
Bit[1] RTC IRQ Select.
0=RTC IRQ on serial IRQ frame
1=RTC IRQ on IRQx pin
Bit[2] SCI Select
0=SCI is on serial IRQ frame
1=SCI is on IRQx pin
Note: Serial IRQs are not available under VTR power.
Bit[3] SCI Polarity Select (EN1)
0=SCI active low
1=SCI active high
Bit[4] SCI Buffer Type (EN1)
0=Push-pull
1=Open drain
Bit[6:5] SCI/PME/IRQ9 Pin select
00=Pin 21 is used for nPME signal.
01=Pin 21 is used for SCI.
10=Pin 21 is used for IRQ9.
11=Reserved
Engineering Note: If bit 5 is set, this overrides the setting
of the IRQ for SCI in Config Register 0x70 of Logical
Device A. See the logic in the SCI section.
Enginreering Note: This bit selects the buffer type of the
pin as follows: if nPME is selected, it is active low OD; if
SCI is selected, the buffer type and polarity are selected
through bits 3 and 4 of this register; if IRQ9 is selected, it
is an active high push-pull output.
Bit[7] SMI Select
0=SMI is on serial IRQ frame (IRQ2)
1=SMI is on nSMI pin
Engineering Note: the polarity and buffer type of the SMI
pin is selected through the GPIO registers (default is active
low open drain).
198
STATE
NAME
Forced Disk Change
REG INDEX
0xC1 R/W
Default = 0x03
on VTR POR
DEFINITION
Force Change 1 and Force Change 0 can be
written to 1 are not clearable by software.
Force Change 1 is cleared on (nSTEP AND nDS1)
Force Change 0 is cleared on (nSTEP AND nDS0).
DSK CHG (Floppy DIR Register, Bit 7) = (nDS0
AND Force Change 0) OR (nDS1 AND Force
Change 1) OR nDSKCHG.
Setting either of the Force Disk Change bits active
(1) forces the FDD nDSKCHG input active when
the appropriate drive has been selected.
Floppy Data Rate
Select Shadow
0xC2 R
UART1 FIFO
Control Shadow
0xC3 R
UART2 FIFO
Control Shadow
0xC4 R
Bit[0] Force Change for FDC0
0=Inactive
1=Active
Bit[1] Force Change for FDC1
0=Inactive
1=Active
Bit[2:7] Reserved, Reads 0
Floppy Data Rate Select Shadow Register
Bit[7] Soft Reset
Bit[6] Power Down
Bit[5] Reserved
Bit[4] PRECOMP 2
Bit[3] PRECOMP 1
Bit[2] PRECOMP 0
Bit[1] Data Rate Select 1
Bit[0] Data Rate Select 0
UART1 FIFO Control Shadow Register
Bit[7] RCVR Trigger MSB
Bit[6] RCVR Trigger LSB
Bit[5] Reserved
Bit[4] Reserved
Bit[3] DMA Mode Select
Bit[2] XMIT FIFO Reset
Bit[1] RCVR FIFO Reset
Bit[0] FIFO Enable
UART2 FIFO Control Shadow Register
Bit[7] RCVR Trigger MSB
Bit[6] RCVR Trigger LSB
Bit[5] Reserved
Bit[4] Reserved
Bit[3] DMA Mode Select
Bit[2] XMIT FIFO Reset
Bit[1] RCVR FIFO Reset
Bit[0] FIFO Enable
199
STATE
NAME
Forced Write Protect
REG INDEX
0xC5 R/W
Default = 0x00
on VTR POR
Ring Filter Select
Register
Default = 0x00 on
Vbat POR
Note 3
0xC6 R/W
DEFINITION
Force Write Protect function forces the FDD
nWRTPRT input active if the FORCE WRTPRT bit is
active. The Force Write Protect function applies to
the nWRTPRT pin in the FDD Interface as well as
the nWRTPRT pin in the Parallel Port FDC.
Bit[0] Force Write Protect bit FDD0
0 = Inactive (Default)
1 = Active “forces the FDD nWRTPRT input active
when the drive has been selected” Note 2
Bit[1:7] Reserved, reads 0.
This register is used to select the operation of the
ring indicator on the nRI1, nRI2 and nRING pins.
Bit[0]: 1=Enable detection of pulse train of
frequency 15Hz or higher for 200msec and
generate an active low pulse for its duration to use
as the ring indicator function on nRING pin. The
leading high-to-low edge is the trigger for the ring
indication.
0=Ring indicate function is high-to-low transition on
the nRING pin.
Bit[1]: 1=Enable detection of pulse train of
frequency 15Hz or higher and generate an active
low pulse for its duration to use for 200msec as the
ring indicator function on nRI1 pin. The leading
high-to-low edge is the trigger for the ring
indication.
0=Ring indicate function is high-to-low transition on
the nRI1 pin.
Bit[2]: 1=Enable detection of pulse train of
frequency 15Hz or higher and generate an active
low pulse for its duration to use for 200msec as the
ring indicator function on nRI2 pin. The leading
high-to-low edge is the trigger for the ring
indication.
0=Ring indicate function is high-to-low transition on
the nRI2 pin.
Bits[7:3] Reserved
STATE
C
Note 1: There are three types of events Type 1, Type 2 and Type 3.
Type 1: This is an event that comes from a pin or internal signal to the chip. This needs to be edge
detected and latched until cleared by a read of the register. The output of the latch is used to turn
on the power supply through the “or” logic.
Type 2:This is an event that comes from a pin or internal signal to the chip. This does not need to
be edge detected and latched. Cleared at the source.
Type 3: This is an event that comes from a pin or internal signal to the chip. This needs to be edge
detected and latched until cleared by a read of the register. The output of the latch is not used to
turn on the power supply through the “or” logic.
200
Note 2: nWRTPRT (to the FDC Core) = (nDS0 AND FORCE WRTPRT 0) OR nWRTPRT (from the FDD
Interface). The Force Write Protect 0 bit also applies to the Parallel Port FDC. This bit applies to both
drives.
Note 3: The ring wakeup filter will produce an active low pulse for the period of time that nRING, nRI1
and/or nRI2, nRI1 and/or nRI2 is toggling.
201
TABLE 84 - AUXILLIARY I/O, LOGICAL DEVICE 8 [LOGICAL DEVICE NUMBER = 0X08]
NAME
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 nSMI
=0 GPI/O
Bits[6:4] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
C
GP11
Default = 0x01
on Vbat POR
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[4:3] Function Select
=00 GPI/O
=01 nRING
=10 Either Edge Triggered Interrupt 1
=11 Reserved
Bits[6:5] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull Bit
C
GP12
0xE2
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[4:3] Function Select
=00 GPI/O
=01 WDT
=10 P17
=11 Either Edge Triggered Interupt 2
Bits[6:5] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull Bit
C
0xE3
General Purpose I/0 bit 1.3
Bit[0] In/Out : =1 Input, =0 Output
C
GP10
Default = 0x01
on Vbat POR
Default = 0x01
on Vbat POR
GP13
202
NAME
Default = 0x01
on Vbat POR
GP14
REG INDEX
DEFINITION
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 LED
=0 GPI/O
Bits[6:4] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull Bit
STATE
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 IRRX2
=0 GPI/O
Bits[6:4] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull Bit
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 IRTX2
=0 GPI/O
Bits[6:4] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
C
0xE6
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 nMTR1
=0 GPI/O
Bits[6:4] Reserved
C
Default = 0x01
on Vbat POR
GP15
Default = 0x00
on Vbat POR
GP16
Default = 0x01
on Vbat POR
203
NAME
REG INDEX
DEFINITION
STATE
Bit[7] Output Type Select
1=Open Drain
0=Push Pull Bit
GP17
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] Group Interrupt Enable
=1 Enable Combined IRQ 1
=0 Disable Combined IRQ 1
Bit[3] Function Select
=1 nDS1
=0 GPI/O
Bits[6:4] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
0xC8
General Purpose I/0 bit 5.0
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 PCI Clock
=01 IRQ14
=10 GPI/O
=11 Reserved
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 5.2
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 DRVDEN1
=01 GPIO
=10 IRQ8
=11 nSMI
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
Default = 0x01
on Vbat POR
GP50
Default = 0x01
on Vbat POR
GP52
Default =0x09
on Vbat POR
0xCA
204
C
NAME
GP53
REG INDEX
0xCB
Default =0x01
on Vbat POR
GP54
0xCC
Default = 0x01
on Vbat POR
GP60
Default = 0x01
on Vbat POR
0xD0
DEFINITION
0=Push Pull
General Purpose I/0 bit 5.3
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 nROMCS
=01 IRQ11
=10 GPI/O
=11 Either Edge Triggered Interrupt 3
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 5.4
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 nROMOE
=01 IRQ12
=10 GPI/O
=11 Either Edge Triggered Interrupt 4
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.0
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD0
=01 IRQ1
=10 GPI/O
=11 nSMI
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
205
STATE
NAME
GP61
REG INDEX
0xD1
Default = 0x01
on Vbat POR
GP62
0xD2
Default = 0x01
on Vbat POR
GP63
Default = 0x01
on Vbat POR
0xD3
DEFINITION
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.1
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD1
=01 IRQ3
=10 GPI/O
=11 LED
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.2
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD2
=01 IRQ4
=10 GPI/O
=11 nRING
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.3
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD3
=01 IRQ5
=10 GPI/O
=11 WDT
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
206
STATE
NAME
GP64
REG INDEX
0xD4
Default = 0x01
on Vbat POR
GP65
0xD5
Default = 0x01
on Vbat POR
GP66
Default = 0x01
on Vbat POR
0xD6
DEFINITION
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.4
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD4
=01 IRQ6
=10 GPI/O
=11 P17
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.5
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD5
=01 IRQ7
=10 GPI/O
=11 Reserved
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.6
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD6
=01 IRQ8
=10 GPI/O
=11 Reserved
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
207
STATE
NAME
GP67
REG INDEX
0xD7
Default = 0x01
on Vbat POR
GP_INT2
0xEF
Default = 0x00
on Vbat POR
GP_INT1
STATE
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/0 bit 6.7
Bit[0] In/Out : =1 Input, =0 Output
Bit[1] Polarity : =1 Invert, =0 No Invert
Bit[2] Reserved
Bit[4:3] Function Select
=00 RD7
=01 IRQ10
=10 GPI/O
=11 Reserved
Bit[5] Group Interrupt Enable
=1 Enable Combined IRQ 2
=0 Disable Combined IRQ 2
Bit[6] Reserved
Bit[7] Output Type Select
1=Open Drain
0=Push Pull
General Purpose I/O Combined Interrupt 2
Bits[2:0] Reserved, = 000
Bit[3] GP IRQ Filter Select
0 = Debounce Filter Bypassed
1 = Debounce Filter Enabled
Bits[7:4] Combined IRQ mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
0xF0
General Purpose I/O Combined Interrupt 1
Bits[2:0] Reserved, = 000
Bit[3] GP IRQ Filter Select
0 = Debounce Filter Bypassed
1 = Debounce Filter Enabled
Bits[7:4] Combined IRQ mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
C
0xF1
Watch Dog Timer Units
Bits[6:0] Reserved, = 00000
Bit[7] WDT Time-out Value Units Select
C
Default = 0x00
on Vbat POR
WDT_UNITS
DEFINITION
208
NAME
REG INDEX
WDT_VAL
0xF2
Watch-dog Timer Time-out Value
Binary coded, units = minutes(default) or seconds,
selectable via Bit[7] of Reg 0xF1, LD 8.
0x00 Time out disabled
0x01 Time-out = 1 minute/second
.........
0xFF Time-out = 255 minutes/seconds
C
0xF3
Watch-dog timer Configuration
Bit[0] Joy-stick Enable
=1WDT is reset upon an I/O read or write of the
Game Port
=0WDT is not affected by I/O reads or writes to the
Game Port.
Bit[1] Keyboard Enable
=1WDT is reset upon a Keyboard interrupt.
=0WDT is not affected by Keyboard interrupts.
Bit[2] Mouse Enable
=1WDT is reset upon a Mouse interrupt
=0WDT is not affected by Mouse interrupts.
Bit[3] PWRLED Time-out enable
=1Enables the Power LED to toggle at a 1Hz rate with
50 percent duty cycle while the Watch-dog Status bit
is set.
=0Disables the Power LED toggle during Watch-dog
timeout status.
Bits[7:4] WDT Interrupt Mapping
1111 = IRQ15
.........
0011 = IRQ3
0010 = Invalid
0001 = IRQ1
0000 = Disable
C
0xF4
Watch-dog timer Control
Bit[0] Watch-dog Status Bit, R/W
=1WD timeout occured
=0WD timer counting
Bit[1] Power LED Toggle Enable, R/W
=1Toggle Power LED at 1Hz rate with 50 percent duty
cycle. (1/2 sec. on, 1/2 sec. off)
=0Disable Power LED Toggle
Bit[2] Force Timeout, W
=1Forces WD timeout event; this bit is self-clearing
Bit[3] P20 Force Timeout Enable, R/W
C
Default = 0x00
on Vcc POR or
Reset_Drv
WDT_CTRL
Default = 0x00
Cleared by VTR
POR
STATE
Note: if the logical device's activate bit is not set then
bits 0 and 1 have no effect.
Default = 0x00
on Vcc POR or
Reset_Drv
WDT_CFG
DEFINITION
= 0 Minutes (default)
= 1 Seconds
Default = 0x00
on Vcc POR or
Reset_Drv
209
NAME
GP1
REG INDEX
DEFINITION
= 1Allows 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.
= 0P20 activity does not generate the WD timeout
event.
Note: The P20 signal will remain high for a minimum
of 1us and can remain high indefinitely. Therefore,
when P20 forced timeouts are enabled, a self-clearing
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 down. 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.
0xF6
This register is used to read the value of the GPIO
pins.
Bit[0]: GP10
Bit[1]: GP11
Bit[2]: GP12
Bit[3]: GP13
Bit[4]: GP14
Bit[5]: GP15
Bit[6]: GP16
Bit[7]: GP17
This register is used to read the value of the GPIO
pins.
Bit[0]: GP50
Bit[1]: Reserved
Bit[2]: GP52
Default = 0x00
on Vbat POR
GP5
Default = 0x00
on Vbat POR
0xF9
210
STATE
NAME
REG INDEX
DEFINITION
STATE
Bit[3]: GP53
Bit[4]: GP54
Bit[7:5]: Reserved
0xFA
This register is used to read the value of the GPIO
GP6
pins.
Bit[0]: GP60
Default = 0x00
Bit[1]: GP61
on Vbat POR
Bit[2]: GP62
Bit[3]: GP63
Bit[4]: GP64
Bit[5]: GP65
Bit[6]: GP66
Bit[7]: GP67
Note:Registers GP1, WDT_CTRL, GP5-6, Soft Power Enable and Status Registers are also available at
index 01-0F when not in configuration mode.
Note: GP10-17 can be enabled onto GPINT1; GP50-54 and GP60-67 can be enabled onto GPINT2.
211
ACPI, Logical Device A
TABLE 85 - ACPI, LOGICAL DEVICE A [LOGICAL DEVICE NUMBER = 0X0A]
NAME
REG INDEX
DEFINITION
STATE
Sleep/Wake
Configuration
Default = 0x00
on Vbat POR
0xF0
This register is used to configure the functionality of
the SLP_EN bit and its associated logic, and the
WAK_STS bit bit and its associated logic. It also
contains the CIR PLL Power bit.
Bit[0] SLP_CTRL. SLP_EN Bit Function.
0=Default. Writing ‘1’ to the SLP_EN bit causes the
system to sequence into the sleeping state associated
with the SLP_TYPx fields.
1=Writing ‘1’ to the SLP_EN bit does not cause the
system to sequence into the sleeping state associated
with the SLP_TYPx fields; instead an SMI is
generated.
Note: the SLP_EN_SMI bit in the SMI Status Register
2 is set whenever ‘1’ is written to the SLP_EN bit; it is
enabled to generate an SMI through bit[0] of this
register.
Bit[1] WAK_CTRL. WAK_STS Bit Function
0=Default. The WAK_STS bit is set on the high-to-low
transition of nPowerOn.
1=The WAK_STS bit is set upon any enabled wakeup
event and the high-to-low transition of nPowerOn.
Bits[2:6] Reserved
Bit[7]: CIR PLL Power.
0=Default. The 32KHz clock PLL is unpowered
1=The 32KHz clock PLL is running and can replace
the 14.318MHz clock source for the CIR wakeup
event.
212
C
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
0.8
V
COMMENTS
I Type Input Buffer
Low Input Level
VILI
High Input Level
VIHI
TTL Levels
V
2.0
IS Type Input Buffer
Low Input Level
VILIS
High Input Level
VIHIS
Schmitt Trigger Hysteresis
VHYS
0.8
2.2
V
Schmitt Trigger
V
Schmitt Trigger
mV
250
ICLK Input Buffer
V
Low Input Level
VILCK
High Input Level
VIHCK
2.2
Low Input Leakage
IIL
-10
+10
μA
VIN = 0
High Input Leakage
IIH
-10
+10
μA
VIN = VCC
0.4
V
Input Leakage
(All I and IS buffers)
218
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
COMMENTS
0.4
V
IOL = 4 mA
V
IOH = -2 mA
+10
μA
VIN = 0 to VCC
(Note 1)
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 = -4 mA
+10
μA
VIN = 0 to VCC
(Note 1)
0.4
V
IOL = 12 mA
V
IOH = -6 mA
+10
μA
VIN = 0 to VCC
(Note 1)
0.4
V
IOL = 12 mA
V
IOH = -6 mA
+10
μA
VIN = 0 to VCC
(Note 1)
0.4
V
IOL = 12 mA
+10
μA
VIN = 0 to VCC
(Note 1)
IO4 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
O4 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
O8 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
IO12 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
O12 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
OD12 Type Buffer
Low Output Level
VOL
Output Leakage
IOL
-10
219
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
COMMENTS
0.4
V
IOL = 14 mA
V
IOH = -14 mA
+10
μA
VIN = 0 to VCC
(Note 1)
VCC=0V; VCC=VTR =0V
VIN = 6V Max
IOP14 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
Backdrive Protected
IIL
± 10
μA
Low Output Level
VOL
0.4
V
IOL = 14 mA
Output Leakage
IOL
+10
μA
VIN = 0 to VCC
(Note 1)
0.4
V
IOL = 14 mA
V
IOH = -14 mA
+10
μA
VIN = 0 to VCC
VCC=0V; VCC=VTR =0V
VIN = 6V Max
OD14 Type Buffer
-10
OP14 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
Backdrive Protected
IIL
± 10
μA
Low Output Level
VOL
0.4
V
IOL = 16 mA
Output Leakage
IOL
μA
VIN = 0 to VCC
V
IOL = 24 mA
V
IOH = -12 mA
μA
VIN = 0 to VCC (Note
1)
IOD16 Type Buffer
-10
O24 Type Buffer
0.4
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
220
+10
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
COMMENTS
0.4
V
IOL = 24 mA
V
IOH = -12 mA
+10
μA
VIN = 0 to VCC
(Note 1)
IO24 Type Buffer
Low Output Level
VOL
High Output Level
VOH
2.4
Output Leakage
IOL
-10
OD24 Type Buffer
Low Output Level
VOL
0.4
V
IOL = 24 mA
Output Leakage
IOL
+10
μA
ChiProtect
(SLCT, PE, BUSY, nACK,
nERROR, GP10-GP17, GP50GP54, GP60-GP67,)
IIL
± 10
μA
VIN = 0 to VCC
(Note 1)
VCC=0V; VCC=VTR
=0V
VIN = 6V Max
Backdrive
(nSTROBE, nAUTOFD, nINIT,
nSLCTIN, PD0-PD7, GP10GP17, GP50-GP54, GP60GP67, nSMI, IRQ8)
IIL
± 10
μA
VCC=0V; VCC=VTR
=0V
VIN = 6V Max
VCC Suppy Current Active
ICCI
4.5
90
mA
All outputs open.
Trickle Supply Voltage
VTR
VCC
min
VCC
max
V
VCC must not be
greater than .5V
above VTR
VTR Supply Current Active3
IVRI
25
mA
All outputs driven
4.0
V
5
μA
100
nA
70
-.5V
3
Battery Supply Voltage
VBAT
2.4
3.0
3
VBAT Supply Current
Standby
VCC=VTR=VSS =0V
VCC=5V, VBAT=3V
Input Leakage
Note 1: Output leakage is are measured with the current pins in high impedance.
Note 2: Output leakage is measured with the low driving output off, either for a high level output or a high
impedance state.
Note 3: Please contact SMSC for the latest values.
221
CAPACITANCE TA = 25°C; fc = 1MHz; 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
222
TEST CONDITION
All pins except pin
under test tied to AC
ground
AC TIMING DIAGRAMS
CAPACITIVE LOADING
For the Timing Diagrams shown, the following capacitive loads are used.
TABLE 86 - CAPACITIVE LOADING
CAPACITANCE
TOTAL (pF)
120
120
60
60
240
240
240
240
240
240
240
240
100
100
100
100
100
100
240
240
240
240
240
240
240
240
240
NAME
SD[0:7]
IOCHRDY
IRQ[1,3-12,14,15]
DRQ[1:3]
nWGATE
nWDATA
nHDSEL
nDIR
nSTEP
nDS[1:0]
nMTR[1:0]
DRVDEN[1:0]
TXD1
nRTS1
nDTR1
TXD2
nRTS2
nDTR2
PD[0:7]
nSLCTIN
nINIT
nALF
nSTB
KDAT
KCLK
MDAT
MCLK
223
IOW Timing Port 92
t3
SAx
t4
SD<7:0>
nIOW
t1
t2
t5
FIGURE 7 - IOW TIMING FOR PORT 92
TABLE 87 - IOW TIMING FOR PORT 92
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
224
0
ns
100
ns
POWER-UP TIMING
t1
t2
Vcc
t3
A ll H o s t
Accesses
FIGURE 8 - POWER-UP TIMING
TABLE 88 - 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
225
500
μs
Button Timing
B u tto n _ In
tF
tR
FIGURE 9 - BUTTON INPUT TIMING
TABLE 89 - 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 r io d
t3
V cc
FIGURE 10 - BUTTON OVERRIDE TIMING
TABLE 90 - 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
226
MIN
4
TYP
ROM INTERFACE
nR O M C S
nRO M O E
t2
t7 N o te 2
t1
t3
t2
t8
t3
R D [x]
t4
N o te 1
t5
t6
S D [x]
FIGURE 11 - ROM INTERFACE TIMING
Note 1: RD[x] driven by FDC37B78x, SD[x] driven by system
Note 2: RD[x] driven by ROM, SD[x] driven by FDC37B78x
TABLE 91 - ROM INTERFACE TIMING
NAME
DESCRIPTION
MAX
UNITS
t1
SD[x] Valid to RD[x] Valid
MIN
TYP
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.
227
ISA WRITE
t10
AEN
t3
SA[x],
t2
t1
t4
t6
nIOW
t5
SD[x]
DATA
t7
FINTR
t8
PINTR
t9
IBF
FIGURE 13 - ISA WRITE TIMING
TABLE 92 - ISA WRITE TIMING
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 1)
55
ns
t8
nIOW deasserted to PINTER deasserted (Note 2)
260
ns
t9
IBF (internal signal) asserted from nIOW deasserted
40
ns
t10
nIOW deasserted to AEN invalid
ns
0
25
10
Note 1: FINTR refers to the IRQ used by the floppy disk
Note 2: PINTR refers to the IRQ used by the parallel port
228
ns
ns
ns
ISA READ
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 14 - ISA READ TIMING
See timing parameters on next page.
229
TABLE 93 - ISA READ TIMING
NAME
DESCRIPTION
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
nIOR asserted to SA[x], nCS invalid
10
t4
nIOR asserted to Data Valid
t5
Data Hold/float from nIOR deasserted
10
t6
nIOR deasserted
25
ns
t8
nIOR asserted 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 3,5)
80
ns
t12
nIOR deasserted to AUXOBF1 deasserted (Notes 4,5)
80
ns
t13
nIOW deasserted to AEN invalid
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
10
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.
230
ns
50
ns
25
ns
ns
8042 CPU
t2
PCOBF
t1
AUXOBF1
nWRT
t3
IBF
nRD
FIGURE 15 - INTERNAL 8042 CPU TIMING
TABLE 94 - INTERNAL 8042 CPU TIMING
NAME
MAX
UNITS
t1
nWRT deasserted to AUXOBF1 asserted (Notes 1,2)
DESCRIPTION
MIN
40
ns
t2
nWRT deasserted to PCOBF asserted (Notes 1,3)
40
ns
t3
nRD deasserted 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.
231
TYP
CLOCK TIMING
t2
t2
CLOCKI
FIGURE 16 - INPUT CLOCK TIMING
TABLE 95 - INPUT CLOCK TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
Clock Cycle Time for 14.318MHZ
70
ns
t2
Clock High Time/Low Time for 14.318MHz
35
ns
t1
Clock Cycle Time for 32KHZ
31.25
μs
t2
Clock High Time/Low Time for 32KHz
16.53
μs
Clock Rise Time/Fall Time (not shown)
5
ns
FIGURE 17 - RESET TIMING
t4
RESET_DRV
TABLE 96 - 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.
232
Single Transfer DMA
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 18 - SINGLE TRANSFER DMA TIMING
See timing parameters on next page.
233
TABLE 97 - SINGLE TRANSFER DMA TIMING
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
100
ns
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
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
234
ns
ns
Burst Transfer DMA Timing
t15
AEN
t16
t3
t2
FDRQ,
PDRQ
t1
t4
nDACK
t12
t14
t11
t6
nIOR
or
nIOW
t8
t5
t10
t9
t7
DATA
(DO-D7)
DATA VALID
DATA VALID
t13
TC
FIGURE 19 - BURST TRANSFER DMA TIMING
See timing parameters on next page.
235
TABLE 98 - BURST TRANSFER DMA TIMING
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
100
ns
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
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
236
ns
ns
DISK DRIVE TIMING
t3
nDIR
t4
t1
t2
nSTEP
t5
nDS0-3
t6
nINDEX
t7
nRDATA
t8
nWDATA
nIOW
t9
t9
nDS0-1,
MTR0-1
FIGURE 20 - DISK DRIVE TIMING (AT MODE ONLY)
TABLE 99 - 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 kb/s MCLK = 8 MHz)
WCLK = 2 x Data Rate (at 500 kb/s WCLK = 1 MHz)
237
SERIAL PORT
nIOW
t1
nRTSx,
nDTRx
t5
IRQx
nCTSx,
nDSRx,
nDCDx
t6
t2
t4
IRQx
nIOW
t3
IRQx
nIOR
nRIx
FIGURE 21 - SERIAL PORT TIMING
TABLE 100 - SERIAL PORT TIMING
NAME
MAX
UNITS
t1
nRTSx, nDTRx Delay from nIOW
DESCRIPTION
MIN
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
238
TYP
Parallel Port
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 22 - PARALLEL PORT TIMING
TABLE 101 - PARALLEL PORT TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
PD0-7, nINIT, nSTROBE, nAUTOFD Delay from nIOW
100
ns
t2
PINTR Delay from nACK, nFAULT
60
ns
t3
PINTR Active Low in ECP and EPP Modes
300
ns
t4
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.
239
200
EPP 1.9 Data or Address Write Cycle
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
PDIR
t21
FIGURE 23 - EPP 1.9 DATA OR ADDRESS WRITE CYCLE
See timing parameters on next page.
240
TABLE 102 - EPP 1.9 DATA OR ADDRESS WRITE CYCLE TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
nIOW Asserted to PDATA Valid
0
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
ns
12
s
t9
nIOW Deasserted to DATA Invalid
0
t10
nIOW Asserted to IOCHRDY Asserted
0
24
ns
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
s
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
185
ns
Note 1: nWAIT must be filtered to compensate for ringing on the parallel bus cable. WAIT is considered
to have settled after it does not transition for a minimum of 50 nsec.
241
EPP 1.9 Data or Address Read Cycle
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
t6
nWAIT
FIGURE 24 - EPP 1.9 DATA OR ADDRESS READ CYCLE
See timing parameters on next page
242
NAME
TABLE 103 - EPP 1.9 DATA OR ADDRESS READ CYCLE TIMING
DESCRIPTION
MIN
TYP
MAX
0
UNITS
t1
PDATA Hi-Z to Command Asserted
30
ns
t2
nIOR Asserted to PDATA Hi-Z
t3
nWAIT Deasserted to Command Deasserted
(Note 1)
0
50
ns
60
180
ns
t4
Command Deasserted to PDATA Hi-Z
0
ns
t5
Command Asserted to PDATA Valid
0
ns
t6
PDATA Hi-Z to nWAIT Deasserted
0
s
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
ns
24
ns
160
ns
40
ns
ns
t11
IOCHRDY Deasserted to nIOR Deasserted
0
t12
nIOR Deasserted to SDATA Hi-Z (Hold Time)
0
ns
t13
PDATA Valid to SDATA Valid
0
75
ns
t14
nWAIT Asserted to Command Asserted
0
195
ns
t15
Time Out
10
12
s
t16
nWAIT Deasserted to PDATA Driven (Note 1)
60
190
ns
t17
nWAIT Deasserted to nWRITE Modified (Notes 1,2)
60
190
ns
85
t18
SDATA Valid to IOCHRDY Deasserted (Note 3)
0
t19
Ax Valid to nIOR Asserted
40
t20
nIOR Deasserted to Ax Invalid
10
10
ns
t21
nWAIT Asserted to nWRITE Deasserted
0
185
ns
185
ns
180
ns
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
ns
ns
ns
ns
t26
PDIR Set to Command
0
20
ns
t27
nWAIT Deasserted to PDIR Low (Note 1)
60
180
ns
t28
Note 1
Note 2
Note 3
nWRITE Deasserted to Command
1
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.
243
ns
EPP 1.7 Data Or Address Write Cycle
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 25 - EPP 1.7 DATA OR ADDRESS WRITE CYCLE
See timing parameters on next page.
244
NAME
TABLE 104 - EPP 1.7 DATA OR ADDRESS WRITE CYCLE TIMING
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
t4
nIOW Deasserted to Command Deasserted (Note 2)
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
35
ns
50
ns
ns
12
s
24
ns
40
ns
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
ns
t18
nIOW Deasserted to Ax Invalid
10
s
t19
nIOW Deasserted to nIOW or nIOR Asserted
100
t20
nWAIT Asserted to IOCHRDY Deasserted
t21
Command Deasserted to nWAIT Deasserted
Note 1
Note 2
ns
ns
45
0
ns
ns
nWRITE is controlled by clearing the PDIR bit to "0" in the control register before performing an
EPP Write.
The number is only valid if nWAIT is active when IOW goes active.
245
EPP 1.7 Data or Address Read Cycle
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 26 - EPP 1.7 DATA OR ADDRESS READ CYCLE
See timing parameters on next page.
246
TABLE 105 - EPP 1.7 DAT OR ADDRESS READ CYCLE TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
50
ns
40
ns
t2
nIOR Deasserted to Command Deasserted
t3
nWAIT Asserted to IOCHRDY Deasserted
t4
Command Deasserted to PDATA Hi-Z
0
ns
t5
Command Asserted to PDATA Valid
0
ns
t8
nIOR Asserted to IOCHRDY Asserted
0
24
ns
50
ns
t10
nWAIT Deasserted to IOCHRDY Deasserted
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
s
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
55
ns
WRITE is controlled by setting the PDIR bit to "1" in the control register before performing an EPP
Read.
247
ECP PARALLEL PORT TIMING
The timing is designed to provide 3 cable
round-trip times for data setup if Data is driven
simultaneously with HostClk (nStrobe).
Parallel Port FIFO (Mode 101)
The standard parallel port is run at or near the
peak 500KBytes/sec 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 28.
Reverse-Idle Phase
The peripheral has no data to send and keeps
PeriphClk high. The host is idle and keeps
HostAck low.
ECP Parallel Port Timing
Reverse Data Transfer Phase
The timing is designed to allow operation at
approximately 2.0 Mbytes/sec over a 15ft cable. If
a shorter cable is used then the bandwidth will
increase.
The interface transfers data and commands from
the peripheral to the host using an interlocked
HostAck and PeriphClk.
The Reverse Data
Transfer Phase may be entered from the ReverseIdle 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 29.
Forward-Idle
When the host has no data to send it keeps
HostClk (nStrobe) high and the peripheral will
leave PeriphClk (Busy) low.
Forward Data Transfer Phase
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.
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
open-collector), the drivers are dynamically
changed from open-collector to totem-pole. The
timing for the dynamic driver change is specified in
the 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.
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. 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 28.
249
t6
t3
PDATA
t1
nSTROBE
t2
t5
t4
BUSY
FIGURE 27 - PARALLEL PORT FIFO TIMING
TABLE 106 - 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
ns
t4
nSTROBE Active to BUSY Active
t5
BUSY Inactive to nSTROBE Active
680
ns
t6
BUSY Inactive to PDATA Invalid (Note 1)
80
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.
251
t3
nAUTOFD
t4
PDATA<7:0>
t2
t1
t7
t8
nSTROBE
BUSY
t6
t5
t6
FIGURE 28 - ECP PARALLEL PORT FORWARD TIMING
TABLE 107 - ECP PARALLEL PORT FORWARD TIMING
NAME
DESCRIPTION
MIN
MAX
UNITS
60
ns
t1
nAUTOFD Valid to nSTROBE Asserted
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
t5
nSTROBE Deasserted to Busy Asserted
0
ns
t6
nSTROBE Deasserted to Busy Deasserted
0
ns
t7
BUSY Deasserted to nSTROBE Asserted (Notes 1,2)
80
200
ns
t8
BUSY Asserted to nSTROBE Deasserted (Note 2)
80
180
ns
Note 1
Note 2
0
TYP
ns
Maximum value only applies if there is data in the FIFO waiting to be written out.
BUSY is not considered asserted or deasserted until it is stable for a minimum of 75 to 130 ns.
252
t2
PDATA<7:0>
t1
t5
t6
nACK
t4
t3
t4
nAUTOFD
FIGURE 29 - ECP PARALLEL PORT REVERSE TIMING
TABLE 108 - ECP PARALLEL PORT REVERSE TIMING
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
PDATA Valid to nACK Asserted
0
ns
t2
nAUTOFD Deasserted to PDATA Changed
0
ns
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
Note 1
Note 2
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.
nACK is not considered asserted or deasserted until it is stable for a minimum of 75 to 130 ns.
253
Serial Port Infrared Timing
IRDA SIR RECEIVE
DATA
0
1
0
1
0
0
1
1
0
1
1
t2
t1
t2
t1
IRRX
n IRRX
Parameter
t1
t1
t1
t1
t1
t1
t1
t2
t2
t2
t2
t2
t2
t2
Pulse Width at
Pulse Width at
Pulse Width at
Pulse Width at
Pulse Width at
Pulse Width at
Pulse Width at
Bit Time at
Bit Time at
Bit Time at
Bit Time at
Bit Time at
Bit Time at
Bit Time at
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
1. Receive Pulse Detection Criteria: A received pulse is considered
received pulse is a minimum of 1 41µs
2. IRRX: L5, CRF1 Bit 0
nIRRX: L5, CRF1 Bit 0 = 0
FIGURE 30 - IRDA SIR RECEIVE TIMING
254
IRDA SIR TRANSMIT
DAT A
0
1
0
t2
t1
t2
t1
1
0
0
1
1
1
0
IRT X
n IRT X
Parameter
t1
t1
t1
t1
t1
t1
t1
t2
t2
t2
t2
t2
t2
t2
Pulse Width at 115kbaud
Pulse Widt h at 57. 6kbaud
Pulse Widt h at 38. 4kbaud
Pulse Widt h at 19. 2kbaud
Pulse Widt h at 9. 6kbaud
Pulse Widt h at 4. 8kbaud
Pulse Widt h at 2. 4kbaud
Bit T ime at 115kbaud
Bit Time at 57.6kbaud
Bit Time at 38.4kbaud
Bit Time at 19.2kbaud
Bit Tim e at 9.6kbaud
Bit Tim e at 4.8kbaud
Bit Tim e at 2.4kbaud
mi n
typ
max
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
u nits
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
Notes:
1. IrDA @ 115k i s HPSIR com pati ble. IrDA @ 2400 wi ll al low compatibilit y with HP95LX
and 48SX.
2. IRT X: L5, CRF 1 Bit 1 = 1 (default)
nI RT X: L5, CRF1 Bit 1 = 0
FIGURE 31 - IRDA SIR TRANSMIT TIMING
255
1
ASK IR Receive
DAT A
0
1
t1
0
1
0
0
1
1
0
t2
IRRX
n IRRX
t3
t4
t5
t6
M IRRX
nM IRRX
Pa ramet er
min
typ
max
units
t1
M odu lated Out put Bit T ime
t2
Off Bit Time
t3
M odu lated Outp ut " On"
0.8
1
1.2
µs
t4
M odu lated Out put " Off"
0.8
1
1.2
µs
t5
M odu lated Outp ut " On"
0.8
1
1.2
µs
t6
M odu lated Out put " Off"
0.8
1
1.2
µs
µs
µs
Note s:
1 . IRRX: L 5, CRF 1 Bit 0 = 1
n IRRX: L5 , CRF 1 Bit 0 = 0 (de fault)
M IRRX, nMI RRX are the mod ulate d ou tpu ts
FIGURE 32 - AMPLITUDE SHIFT KEYED IR RECEIVE TIMING
256
1
1
ASK IR Transmit
DATA
0
1
t1
0
1
0
0
1
1
0
1
t2
IRTX
n IRTX
t3
t4
t5
t6
MIRTX
nMIRTX
Parameter
min
typ
max
units
t1
Modulated Output Bit Time
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
µs
Notes:
1. IRTX: L5, CRF1 Bit 1 = 1 (default)
nIRTX: L5, CRF1 Bit 1 = 0
MIRTX, nMIRTX are the modulated outputs
FIGURE 33 - ASK IR TRANSMIT TIMING
257
1
D
3
D1
102
65
103
3
DETAIL "A"
64
R1
R2
0
L
4
L1
E
E1
e
5
D1/4
W
2
E1/4
39
128
38
1
A
A2
H
0
0.10
1
SEE DETAIL "A"
A1
-C-
MIN
A
A1
A2
D
D1
E
E1
H
0.05
2.55
23.65
19.9
17.65
13.9
NOM
23.9
20
17.9
14
MAX
3.4
0.5
3.05
24.15
20.1
18.15
14.1
L
L1
e
0
W
R1
R2
MIN
0.65
NOM
0.8
1.95
MAX
0.95
0.5BSC
0
0.1
0.13
0.13
7
0.3
0.3
Notes:
1) Coplanarity is 0.08 mm or 3.2 mils maximum.
2) Tolerance on the position of the leads is 0.080 mm maximum.
3) Package body dimensions D1 and E1 do not include the mold protrusion. Maximum
mold protrusion is 0.25 mm.
4) Dimensions for foot length L measured at the gauge plane 0.25 mm above the seating plane.
5) Details of pin 1 identifier are optional but must be located within the zone indicated.
6) Controlling dimension: millimeter
FIGURE 34 - 128 PIN QFP PACKAGE OUTLINE
257
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