NSC PC87200VUL160A

PC87200 PCI to ISA Bridge
1.0 General Description
2.2 PCI-to-ISA Bridge
– PCI 2.1 compliant 33 MHz bus
– Supports PCI initiator-to-ISA and ISA master-to-PCI
cycle translations
– Subtractive agent for unclaimed transactions (see the
PROHIBIT signal description for exceptions)
– Parallel to Serial IRQ conversion including
IRQ3,4,5,6,7,9,10,11,12,14,15
– Supports 4 ISA slots directly without buffering
– Programmable ISA clock (8.33 to 11 MHz)
– Slow slew rate on edges
The PC87200 Enhanced Integrated PCI-to-ISA bridge
works with an LPC chipset to provide ISA slot support. It is
a complement to the National Semiconductor PC8736x
Super I/O family.
2.0 Features
2.1 General
– Functionally compatible with Intel 82380AB
– 5.0 V tolerant PCI and ISA interfaces
– Slave mode serialized IRQ support for both quiet and
continuous modes
– PC/PCI DMA support
– 32-bit address decode for the 1MB BIOS ROM
– Supports ISA bus mastering
– 160-pin PQFP package
2.3 "PROHIBIT" functional support
– Disables PCI bus subtractive decoding when PROHIBIT is asserted
Block Diagram
PCI Bus
Serialized IRQ
Interface
PCI to X-Bus / X-Bus to PCI Bridge
PC87200 Support
PCI Configuration
Registers
Decoding logic
X-Bus Arbiter
PROHIBIT
BPD#
X-Bus
PCPCIREQ#
Serial IRQ Slave
mode interface logic
ISA bus Target
Interface
ISA bus Master
Interface
PC/PCI DMA
Interface
PCPCIGNT#
ISA Bus
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
www.national.com
PC87200 PCI to ISA Bridge
August 1999
Table of Contents
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.2
PCI-to-ISA Bridge . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.3
"PROHIBIT" functional support . . . . . . . . . . . . . . . 1
Device Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1
PCI Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2
ISA Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.3
Serialized IRQ support . . . . . . . . . . . . . . . . . . . . . . 3
3.4
PROHIBIT signal support . . . . . . . . . . . . . . . . . . . 5
3.5
PC/PCI DMA Interface Support . . . . . . . . . . . . . . . 5
Device Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1
Signal Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.2
Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.3
Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . 9
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1
Register Summary . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2
Chipset Register Space . . . . . . . . . . . . . . . . . . . . 17
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . 22
8.1
Electrical Specifications . . . . . . . . . . . . . . . . . . . . 22
8.2
PC87200Test Modes . . . . . . . . . . . . . . . . . . . . . . 22
8.3
Electrical Connections . . . . . . . . . . . . . . . . . . . . . 29
8.4
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . 29
8.5
Recommended Operating Conditions . . . . . . . . . 29
8.6
DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . 30
8.7
AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . 31
Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2
www.national.com
3.0 Device Overview
The PC87200 can be described as providing the functional ter devices, and a PC/PCI DMA master for DMA transfer
cycles. The PC87200 supports positive decode for the
blocks shown in Figure 1.
BIOS ROM in the special test mode and implements sub— PCI bus master/slave interface
tractive decode for unclaimed PCI accesses when the
— ISA bus master/slave interface
PROHIBIT signal is low. The PC87200 also generates
address and data parity and performs parity checking.
— Serial IRQ slave mode interface
— PROHIBIT signal support
Configuration registers are accessed through the PCI interface using the PCI Bus Type 1 configuration mechanism as
— PC/PCI DMA interface
described in the PCI 2.1 Specification.
3.1 PCI Bus Interface
The PC87200 provides a PCI bus interface that is both a
slave for PCI cycles initiated by the CPU or other PCI masPCI Bus
Serialized IRQ
Interface
PCI to X-Bus / X-Bus to PCI Bridge
PC87200 Support
PCI Configuration
Registers
Decoding logic
X-Bus Arbiter
PROHIBIT
BPD#
X-Bus
PCPCIREQ#
Serial IRQ Slave
mode interface logic
ISA bus Master
Interface
ISA bus Target
Interface
PC/PCI DMA
Interface
PCPCIGNT#
ISA Bus
Internal Block Diagram
3.2 ISA Bus Interface
ized IRQ defined in the Serialized IRQ on the “PCI way” Version 6.0 specification. Programming of the serial interThe PC87200 provides an ISA bus interface for subtracrupt controller when the controller is currently running can
tive-decoded memory and I/O cycles on PCI. The
produce unexpected results.
PC87200 is the default subtractive decoding agent and will
forward all unclaimed memory and I/O cycles to the ISA
interface; however, the PC87200 may be configured to
ignore either I/O, memory or all unclaimed cycles (subtractive decode disabled) by asserting the PROHIBIT signal.
ISA master cycles will only be passed to the PCI bus if they
access memory. I/O accesses are left to complete on the
ISA bus.
ISA master cycles that access memory on ISA bus are not
supported by the PC87200.
3.3 Serialized IRQ support
The PC87200’s Serial Interrupt interface uses a serial
interrupt bus to transmit ISA Bus legacy interrupt requests.
The bus is a one pin bus (SERIRQ) and uses the PCI clock
as its timing reference. The serial interrupt bus is a multidrop bus that is shared by all PCI devices that have legacy
interrupts. The serial interrupt logic conforms to the serial-
3
www.national.com
3.0 Device Overview (Continued)
Timing of the serialized IRQ is illustrated as follows.
START CYCLE
IRQ0
START
R
T
S
R
IRQ1
T
S
R
PCI CLK
START
SERIRQ
Driving
Source
Master
Slave (Q)
Master (C)
NONE
NONE
IRQ1 Source
R = Recovery; T= Turn-around; S = Sample
Start Cycle Timing
S
R
STOP CYCLE
IOCHK#
IRQ15
T
S
R
T
STOP(NOTE 1)
R
T
PCI CLK
SERIRQ
Driving
Source
START
IRQ15 Source
NONE
NONE
Master
NONE
R = Recovery; T= Turn-around; S = Sample
NOTE 1: The Stop pulse is 2 clocks wide for Quiet mode, 3 clocks wide for Continuous mode
Stop Cycle Timing
IRQ Sample Period is three clocks long, with the first clock
being the Sampled phase, the second clock being the
Recovery phase, and the third clock being the Turn-around
phase. During the Sample phase the Serial Interrupt
device drives SERIRQ low if its associated IRQ signal/data
is presently low. If its IRQ signal/data is high the Serial
Interrupt device must TRI-STATE SERIRQ. During the
Recovery phase, the Serial Interrupt device that drove
SERIRQ low (if any Serial Interface device does) is
required to drive back high. During the Turn-around phase
all Serial Interface devices will TRI-STATE SERIRQ. All
Serial Interface devices will drive SERIRQ low at the
appropriate sample point regardless of which device initiated the sample activity, if its associated IRQ signal/data is
low.
3.3.1 Serial Interrupts (Slave Mode)
There are two types of Serial Interrupt transfer modes; the
following describes the operation of the PC87200’s Serial
Interrupt Interface as a Slave:
1. Quiet Mode: Any Serial Interrupt device may initiate a
Start Cycle, while the Serial Interrupt interface is Idle, by
driving SERIRQ low for one PCI clock period. After driving low for one clock the device should immediately TRISTATE® SERIRQ, without ever driving this signal high.
A Start Cycle may not be initiated in the middle of an active Serial Interrupt transfer. Between Stop and Start Cycles the SERIRQ signal will be pulled high and the Serial
Interrupt interface will be Idle.
When the PC87200 Serial Interrupt interface must initiate a Start Cycle in order to transfer any pending interrupt request to the Master. The only exception to this
requirement is when a Serial Interrupt transfer sequence
is already in progress and the PC87200 can transfer the
request during this present Serial Interrupt transfer sequence, then the Serial Interrupt device is not required to
generate another Start Cycle.
2. Continuous Mode: The PC87200 tracks both the Start
and Stop Frames and is responsible for inserting its interrupt requests on the appropriate IRQ frames.
Slave
The PC87200 will support the interrupt request frames
listed in the following table.
The Generation clock for each IRQ follows the low to high
edge of the Start Pulse by the number of PCI Clocks listed
in Table 1.
Note: : The number of clocks equals:
(3 x (IRQ number + 1)) - 1
3.3.3 Stop Cycle Control
The PC87200 will monitor SERIRQ for a Stop Cycle, so
that it may initiate a Start Cycle for a pending transition in
Once a Start Cycle has been initiated all Serial Interrupt any of its IRQs (Quiet Mode). For Continuous Mode, the
devices watch for the rising edge of the Start Pulse and PC87200 will not initiate any Start Cycle, but will track the
start counting IRQ Sample periods from that point. Each Start and Stop Cycles and insert its IRQs appropriately.
3.3.2 IRQ Sampling Periods
4
www.national.com
3.0 Device Overview (Continued)
3.4 PROHIBIT signal support
Table 1. SERIRQ Slave Generation Periods
The chipset will use this signal to claim the BIOS first and
then deassert the "PROHIBIT" signal to configure the PCI
to ISA bridge to continue the boot sequence.
SERIRQ
Period
Signal Generated
# of clocks past
Start
1
Reserved.
2
2
Reserved.
5
3
Reserved.
8
4
IRQ3
11
5
IRQ4
14
PROHIBIT will be a don’t care in this test mode at boot up
for the ROM BIOS range, but should function normally after
booting
6
IRQ5
17
3.5 PC/PCI DMA Interface Support
7
IRQ6
20
8
IRQ7
23
9
Reserved.
26
10
IRQ9
29
11
IRQ10
32
The PC87200 operates as a PC/PCI DMA Secondary Arbitration Bridge. The PC87200 can pass all seven legacy ISA
bus DMA channel requests to the PC/PCI DMA Primary
Bus Arbiter using the channel passing protocol defined in
the Moble PC/PCI DMA Arbitration and Protocol Specification (Revision 2.2). Figure 1 shows the topology of the
PC87200 PC/PCI DMA requests and grants:
12
IRQ11
35
13
IRQ12
38
14
Reserved.
41
15
IRQ14
44
16
IRQ15
47
17
IOCHK#
50
21:18
Reserved.
62,59,56, 53
Special test mode support is provided by means of the
BPD# pin. When this test mode is active, the PC87200 will
enable positive memory decode during boot up to enable
the host to look for boot ROM on ISA card.
The PC87200 converts the seven legacy ISA bus DMA
requests (DREQ0, 1, 2, 3, 5, 6 and 7) into a serial PC/PCI
DMA compliant REQ# sequence and converts the corresponding PC/PCI DMA GNT# sequence into the appropriate DMA acknowledge (DACK0-3, 5-7#). This PC/PCI DMA
expansion Channel Passing Protocol is illustrated
Figure 2.
PC/PCI DMA
Primary Bus
Arbiter
PCI Bus
PCPCIGNT#
PCPCIREQ#
PC87200
DACK7#
DREQ7
DACK6#
DREQ6
DACK5#
DREQ5
DACK3#
DREQ3
DACK2#
DREQ2
DACK1#
DREQ1
DACK0#
DREQ0
PC/PCI DMA Interface Support
ISA Bus
Figure 1. PC87200 PC/PCI DMA Topology
PCICLK
PCPCIREQ#
start
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
start
PCPCIGNT#
bit 0
bit 1
bit 2
Figure 2. Channel Passing Protocol
5
www.national.com
3.0 Device Overview (Continued)
3.5.4 Clock Generation
When a legacy ISA bus DMA request is asserted, the
PC87200 will transmit that request to the PC/PCI Primary
Bus Arbiter by encoding it and driving it out the PC87200’s
PCPCIREQ# according to the above; first PCPCIREQ# will
be driven low for one PCICLK period to indicate that the
serial encoded request transfer is starting. Then the
PC87200 will drive each of the next eight bits with the value
of its corresponding DREQ. (NOTE: Channel 4 will always
be driven low.) At the end of the request sequence, the
PC87200 will continue to drive its PCPCIREQ# signal
active, indicating that the request is still being maintained.
The PC87200 generates the ISA clock using PCI clock signal (typically 33 MHz).
A PCICLK divisor (3,4) is programmable through PCI configuration register to generate the ISA clock signal. This
provides support for the generation of ISACLK frequencies
8.33 MHz and 11 MHz off of a 33MHz PCICLK.
Figure 3. shows a block diagram for clock generation within
the PC87200.
In response to the request sequence, the PC/PCI Primary
Bus Arbiter will respond with a PC/PCI DMA encoded grant
transfer when it is granting the PCI bus for a PC/PCI DMA
transfer cycle. The PC/PCI encoded grant transfer will
begin when the PC/PCI Primary Bus Arbiter drives
PCPCIGNT# low for one PCICLK period to indicate the
start of the grant sequence; then the next three
PCPCIGNT# signal PCICLK periods will then contain the
encoded grant value, indicating which legacy ISA DMA
channel is being granted the PC Bus.
bit 2
bit 1
bit 0
0
0
0
DMA Channel 0 (DACK0#)
0
0
1
DMA Channel 0 (DACK1#)
0
1
0
DMA Channel 0 (DACK2#)
0
1
1
DMA Channel 0 (DACK3#)
1
0
0
RESERVED
1
0
1
DMA Channel 0 (DACK5#)
1
1
0
DMA Channel 0 (DACK6#)
1
1
1
DMA Channel 0 (DACK7#)
PC87200
PCICLK
Channel Granted
N
SYSCLK
Figure 3. PC87200 Clock Generation
After receiving a valid grant from the PC/PCI DMA Arbiter,
the PC87200 will recognize the following I/O accesses as
DMA I/O Reads(Writes) from (to) the granted legacy ISA
DMA channel.
DMA Cycle
Type
DMA
TC (A2) PCI Cycle Type
I/O Address
Normal
0000_0000h
0
I/O Read/Write
Normal TC
0000_0004h
1
I/O Read/Write
Verify
0000_00C0h
0
I/O Read
Verify TC
0000_00C4h
1
I/O Read.
PCI bus address bit 2 (A2) indicates if the cycle is to be a
Terminal Count cycle or not.
For Normal DMA Cycles, PCI bus I/O Reads and Writes
will be translated to legacy ISA DMA Reads and Writes
respectively. For Verify DMA Cycles, only PCI bus I/O
Reads will be translated to legacy ISA DMA Verify cycles.
6
www.national.com
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
Vdd
Vss
SA18
SA19
IRQ9
DACK2#
DREQ2
SYSCLK
SD7
SD6
SD5
SD4
IOCHK#
REFRESH#
SD3
SD2
SD1
SD0
Vdd
Vss
IOCHRDY
SMEMR#
AEN
SMEMW#
IOR#
IOW#
BALE
MEMCS16#
IOCS16#
SA20
SA21
SA22
SA23
IRQ10
IRQ11
IRQ12
IRQ15
IRQ14
Vdd
Vss
DACK0#
DREQ0
MEMR#
MEMW#
DACK5#
DREQ5
SD8
SD9
SD10
SD11
DACK6#
DREQ6
SD12
SD13
SD14
SD15
DACK7#
DREQ7
Vdd
Vss
MASTER#
SBHE#
TC
BPD#
AD31
AD30
AD29
AD28
AD27
AD26
Vdd
Vss
AD25
AD24
C/BE3#
IDSEL
AD23
AD22
Vdd
Vss
160
159
158
157
156
155
154
153
152
151
150
149
148
147
146
145
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
SA17
SA16
SA15
SA14
SA13
SA12
SA11
SA10
SA9
Vss
Vdd
SA8
SA7
SA6
SA5
SA4
SA3
SA2
SA1
SA0
Vss
Vdd
PROHIBIT
DREQ1
DACK1#
RSTDRV
DREQ3
DACK3#
IRQ7
IRQ6
IRQ5
IRQ4
IRQ3
SERIRQ
PCPCIGNT#
PCPCIREQ#
PCIRST#
PCICLK
Vss
Vdd
4.0 Device Pinout
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
7
AD0
AD1
AD2
AD3
AD4
AD5
Vss
Vdd
AD6
AD7
C/BE0#
AD8
AD9
AD10
Vss
Vdd
AD11
AD12
AD13
AD14
AD15
C/BE1#
Vss
Vdd
PAR
SERR#
STOP#
DEVSEL#
TRDY#
IRDY#
Vss
Vdd
FRAME#
C/BE2#
AD16
AD17
AD18
AD19
AD20
AD21
www.national.com
5.0 Pin Descriptions
5.1 Signal Definitions
This section defines the signals and describes the external interface of the PC87200. The following diagram shows the
pins organized by their functional groupings. Internal test and electrical pins are not shown.
Serialized
SERIRQ
PCICLK
SYSCLK
IRQ Interface
AD[31:0]
C/BE[3:0]#
IDSEL
Clocks
PCIRST#
PC87200
RSTDRV
Reset
Enhanced Integrated PCI-to-ISA
Bridge
PCI Bus
SA[23:0]
SD[15:0]
IOCHK#
SBHE#
BALE
IOCHRDY
REFRESH#
IOCS16#
IOR#
IOW#
MEMCS16#
MEMR#
MEMW#
AEN
IRQ[15:14], [12:9], [7:3]
MASTER#
FRAME#
IRDY#
TRDY#
STOP#
DEVSEL#
PAR
SERR#
PCPCIREQ#
PCPCIGNT#
ISA Bus
DREQ[7:5], [3:0]
DACK#[7:5], [3:0]
TC
SMEMW#
SMEMR#
PROHIBIT
BPD#
PC87200 Signal Groups
8
www.national.com
5.0 Pin Descriptions (Continued)
5.2 Pin Assignments
The tables in this section use several common abbreviations. Table 2. lists the mnemonics and their meanings.
In the next section, description of each signal within its associated functional group is provided.
Table 2. Pin Type Definitions
Mnemonic
Definition
I
Standard input pin.
I/O
Bidirectional pin.
O
Totem-pole output.
OD
Open-drain output structure that allows multiple devices to share the pin in a wired-OR configuration.
PU
Pull-up resistor.
PD
Pull-down resistor.
smt
Schmitt Trigger.
s/t/s
Sustained TRI-STATE, an active-low TRI-STATE signal owned and driven by one and only one agent at a
time. The agent that drives an s/t/s pin low must drive it high for at least one clock before letting it float. A
new agent cannot start driving an s/t/s signal any sooner than one clock after the previous owner lets it float.
A pull-up resistor is required to sustain the inactive state until another agent drives it and must be provided
by the central resource.
t/s
TRI-STATE signal.
VDD (PWR) Power pin.
VSS (GND) Ground pin.
#
The "#" symbol at the end of a signal name indicates that the active, or asserted state occurs when the signal
is at a low voltage level. When "#" is not present after the signal name, the signal is asserted when at a high
voltage level.
5.3 Signal Descriptions
5.3.1 Reset Signals
Signal Name
Pin
No.
Type
PCIRST#
124
I
RSTDRV
135
O
Description
PCI Reset
PCIRST# is the reset signal for the PCI bus.
Reset Drive
This signal is asserted to reset devices that reside on the ISA bus. It will be driven
by the inverse of the PCIRST# input signal.
5.3.2 Clock Interface Signals
Signal Name
PCICLK
Pin No.
Type
123
I
Description
PCI Clock
This clock runs at the PCI clock frequency and is used to drive most of the
PC87200 circuitry.
SYSCLK
8
O
ISA Bus Clock
ISACLK is derived from PCICLK and is typically programmed for 8.33MHz.
F0 Index 50h[2:0] is used to program the ISA clock divisor. These bits determine
the divisor of the PCI clock used to generate the ISA bus clock. If F0 Index
50h[2:0] is set to:
010 = Divide by three (sysclk=11MHz)
011 = Divide by four (sysclk = 8.33MHz)
All other values are invalid and can produce unexpected results.
9
www.national.com
5.0 Pin Descriptions (Continued)
5.3.3 PCI Interface Signals
Signal Name
AD[31:0]
C/BE[3:0]#
Pin No.
Type
65,66,
67,68,
69,70,
73,74,
77,78,
81,82,
83,84,
85,86,
100,101,
102,103,
104,107,
108,109,
111,112,
115,116,
117,118,
119,120
I/O
t/s
75,87,
99,110
I/O
t/s
Description
PCI Address/Data
AD[31:0] is a physical address during the first clock of a PCI transaction; it is the
data during subsequent clocks.
When the PC87200 is a PCI master, AD[31:0] are outputs during the address
and write data phases, and are inputs during the read data phase of a transaction.
When the PC87200 is a PCI slave, AD[31:0] are inputs during the address and
write data phases, and are outputs during the read data phase of a transaction.
PCI Bus Command and Byte Enables
During the address phase of a PCI transaction, C/BE[3:0]# defines the bus command. During the data phase of a transaction, C/BE[3:0]# are the data byte enables.
C/BE[3:0]# are outputs when the PC87200 is a PCI master and are inputs when
it is a PCI slave.
IDSEL
76
I
Initialization Device Select
It is used as a chip select during configuration read and write transactions.
FRAME#
88
I/O
t/s
PCI Cycle Frame
FRAME# is asserted to indicate the start and duration of a transaction. It is deasserted on the final data phase.
FRAME# is an input when the PC87200 is a PCI slave.
IRDY#
91
I/O
t/s
PCI Initiator Ready
IRDY# is driven by the master to indicate valid data on a write transaction, or that
it is ready to receive data on a read transaction.
When the PC87200 is a PCI slave, IRDY# is an input that can delay the beginning of a write transaction or the completion of a read transaction.
Wait cycles are inserted until both IRDY# and TRDY# are asserted together.
TRDY#
92
I/O
t/s
PCI Target Ready
TRDY# is asserted by a PCI slave to indicate it is ready to complete the current
data transfer.
TRDY# is an input that indicates a PCI slave has driven valid data on a read or
a PCI slave is ready to accept data from the PC87200 on a write.
TRDY# is an output that indicates the PC87200 has placed valid data on
AD[31:0] during a read or is ready to accept the data from a PCI master on a
write.
Wait cycles are inserted until both IRDY# and TRDY# are asserted together.
STOP#
94
I/O
t/s
PCI Stop
As an input, STOP# indicates that a PCI slave wants to terminate the current
transfer. The transfer will be aborted, retried, or disconnected.
As an output, STOP# is asserted with TRDY# to indicate a target disconnect, or
without TRDY# to indicate a target retry.
10
www.national.com
5.0 Pin Descriptions (Continued)
Signal Name
DEVSEL#
Pin No.
Type
93
I/O
t/s
Description
PCI Device Select
DEVSEL# is asserted by a PCI slave, to indicate to a PCI master and subtractive
decoder that it is the target of the current transaction.
As an input, DEVSEL# indicates a PCI slave has responded to the current address.
As an output, DEVSEL# is asserted one cycle after the assertion of FRAME#
and remains asserted to the end of a transaction as the result of a positive decode. DEVSEL# is asserted four cycles after the assertion of FRAME# if the
PC87200 is selected as the result of a subtractive decode. The subtractive decode sample point can be configured in F0 Index 41h[2:1]. These cycles are
passed to the ISA bus.
PAR
96
I/O
t/s
PCI Parity
PAR is the parity signal driven to maintain even parity across AD[31:0] and
C/BE[3:0]#.
The PC87200 drives PAR one clock after the address phase and one clock after
each completed data phase of write transactions as a PCI master. It also drives
PAR one clock after each completed data phase of read transactions as a PCI
slave.
SERR#
95
O
OD
PCI System Error
SERR# is pulsed by a PCI device to indicate an address parity error.
11
www.national.com
5.0 Pin Descriptions (Continued)
5.3.4 ISA Bus Interface Signals
Signal Name
MASTER#
Pin No.
Type
61
I
Description
ISA Master Mode: Master
The MASTER# input asserted indicates an ISA bus master is driving the ISA bus
and that it may access any device on the system board.
SA[23:0]
SD[15:0]
SMEMW#
33,32,
31,30,
4,3,160,
159,158,
157,156,
155,154,
153,152,
149,148,
147,146,
145,144,
143,142,
141
I/O
56,55,
54,53,
50,49,
48,47,
9,10,
11,12,
15,16,
17,18
I/O
24
O
System Address Bus
This bus carries the addresses for all ISA cycles.
System Data Bus
This bus carries the data for all ISA cycles.
System Memory Write
SMEMW# is output on this pin. SMEMW# is asserted for any memory write accesses below 1MB. It enables 8-bit memory slaves to decode the memory address on SA[19:0].
SMEMR#
22
O
System Memory Read
SMEMR# is output on this pin. SMEMR# is asserted for memory read accesses
below 1MB. It enables 8-bit memory slaves to decode the memory address on
SA[19:0].
SBHE#
62
I/O
System Bus High Enable
The PC87200 or ISA master asserts SBHE# to indicate that SD[15:8] will be
used to transfer a byte at an odd address.
SBHE# is an output during non-ISA master DMA operations. It is driven as the
inversion of AD0 during 8-bit DMA cycles. It is forced low for all 16-bit DMA cycles.
SBHE# is an input during ISA master operations.
BALE
27
I/O
Buffered Address Latch Enable/Special Test mode
BALE indicates when SA[23:0] and SBHE# are valid and may be latched. This
pin will be used as strap for special test mode with the PROHIBIT signal by
checking its input level during reset.
IOCHRDY
21
I/O
OD
I/O Channel Ready
IOCHRDY deasserted indicates that an ISA slave requires additional wait states.
When the PC87200 is an ISA slave, IOCHRDY is an output indicating additional
wait states are required.
REFRESH#
14
I/O
Refresh Cycle indicator
OD
The PC87200 supports the standard ISA refresh function. When the ISA bus is
not in use by the ISA bus controller, the DMA controller, or an ISA bus master,
the refresh control logic will generate an ISA refresh cycle. The 87200 also supports refresh requests initiated by ISA masters.
12
www.national.com
5.0 Pin Descriptions (Continued)
Signal Name
IOCS16#
Pin No.
Type
29
I
Description
I/O Chip Select 16
IOCS16# is asserted by 16-bit ISA I/O devices based on an asynchronous decode of SA[15:0] to indicate that SD[15:0] may be used to transfer data (8-bit ISA
I/O devices use SD[7:0]).
IOR#
25
I/O
I/O Read
IOR# is asserted to request an ISA I/O slave to drive data onto the data bus.
IOW#
26
I/O
I/O Write
MEMCS16#
28
I/O
OD
Memory Chip Select 16
I/O
Memory Read
IOW# is asserted to request an ISA I/O slave to accept data from the data bus.
MEMR#
43
MEMCS# is asserted by 16-bit ISA memory devices based on an asynchronous
decode of SA[23:17] to indicate that SD[15:0] may be used to transfer data (8bit ISA memory devices use SD[7:0]).
MEMR# is asserted for all memory read accesses (including those above 1MB).
It enables 16-bit memory slaves to decode the memory address on SA[23:0].
MEMW#
44
I/O
Memory Write
MEMW# is asserted for all memory write accesses (including those above 1MB).
It enables 16-bit memory slaves to decode the memory address on SA[23:0].
AEN
23
O
Address Enable
AEN asserted indicates to ISA memory devices that a valid address for a DMA
transfer is present on SA[23:0], and for I/O devices to ignore this address and
any data on the ISA bus.
IRQ[15:14], [12:9],
[7:3]
37,38,
36,35,
34,5,
132,131,
130,129,
128
I
DREQ[7:5],
DREQ[3:0]
58 52,
46,134,
7,137,42
I
DACK[7:5]#,
DACK[3:0]#
57,51,
45,133,
6,136,41
O
TC
63
O
IOCHK#
13
I
ISA Bus Interrupt Request
IRQ inputs are interrupts that indicate ISA devices or other devices requesting a
CPU interrupt service.
DMA Request - Channels [7:5], [3:0]
DREQ inputs are asserted by ISA DMA devices to request a DMA transfer. The
request must remain asserted until the corresponding DACK# is asserted.
DMA Acknowledge- Channels [7:5], [3:0]
DACK# outputs are asserted to indicate when a DREQ is granted and the start
of a DMA cycle.
Terminal Count
TC signals the final data transfer of a DMA transfer.
I/O channel check
Asserted by an ISA device indicating an error condition.
5.3.5 Miscellaneous Signals (Continued)
Signal Name
SERIRQ
PROHIBIT
Pin No.
Type
127
I/O
Serial IRQ
s/t/s
This is a one pin bus that conveys interrupt source information to the chipset.
138
I
Description
PROHIBIT
An active high signal from the chipset indicating that the PC87200 should not act
as the subtractive decode agent on the PCI bus.
BPD#
64
I
BIOS Positive Decode (active low)
When this pin is asserted low after BALE is detected high after reset, the PROHIBIT signal will be a don’t care. The BIOS memory range will be positively decoded and claimed as such. All other cycles are still subtractively decoded.
13
www.national.com
5.0 Pin Descriptions (Continued)
5.3.6 PC/PCI signals
PCPCIREQ#
125
O
PC/PCI Bus Request
The PC87200 asserts PCPCIREQ# using the PC/PCI DMA request protocol in
response to a DMA request or ISA master request to gain ownership of the PCI
bus. The PCPCIREQ# and PCPCIGNT# signals are used to arbitrate for the PCI
bus.
PCPCIGNT#
126
I
PC/PCI Bus Grant
PCPCIGNT# is asserted using the PC/PCI DMA grant protocol by an arbiter that
indicates to the PC87200 that access to the PCI bus has been granted.
5.3.7 Power, Ground, and Reserved Terminals
Pin No.
Type
VDD
Signal Name
1,19,39,
59,71,
79,89,
97,105,
113,121,
139,150
PWR
3.3V (nominal) Power Connection
Description
VSS
2,20,40,
60,72,
80,90,
98,106,
114,122,
140,151
GND
Ground Connection
14
www.national.com
6.0 Configuration
a. Connect the NOGO signal of the south bridge to Prohibit cards with option ROM (e.g.,VGA cards, SCSI cards) to
pin of PC87200, SERIRQ to SERIRQ, REQ[A] to work properly.
PCPCIREQ#, GNT[A] to PCPCIGNT# (other PC/PCI REQ,
GNT pair may also be used). If BPD# is not being used, it
should be pulled high.
b. On power-up reset (i.e., cold boot), the NOGO signal is
high on reset and therefore disables the subtractive decoding capability of PC87200. The rationale for doing this is as
follows: on the PCI bus, only one subtractive decoding
agent can exist. Since the south bridge will normally power
up as the subtractive decoding agent, the PC87200 must
be “prohibited” from doing so. Any other GPO pin which is
high on reset can also be used.
c. After PCI bus enumeration, when the device ID and vendor ID of PC87200 is found, do the following:
d. Enable serial IRQ in continuous mode, 21 frames and 4
clock start frame by setting register 64h of south bridge to
d0h. (In the old south bridge, the serial IRQ pin is multiplexed with a GPIO and need to be selected as serial IRQ.
In the latest industry standard south bridge, however, the
serial IRQ is a dedicated pin and does not require initialization.)
e. Enable PC/PCI DMA by setting the PC/PCI request and
grant pins to PC/PCI DMA mode, instead of using them as
GPIOs. Any PC/PCI request and grant pair can be used,
but on the south bridge, GNT[B] is multiplexed with GNT[5],
so PC/PCI request and grant pair A is more preferable to
use.
Set all channels of DMA to PC/PCI DMA except for channels 4 & 2 (channel 4 is for cascading the DMAC and channel 2 is for FDC). The value to be put in register 91:90 is
5475 for the latest south bridge and 5455 for older south
bridges. The difference is due to the use of “11” for LPC
DMA, and the value of 00 (ISA DMA) being put into
reserved instead.
f. Enable positive decode for the devices under the new
south bridge: program the value of 3C0F into reg. E7:E6
will enable positive decode for most devices except sound
and gameport. Changing it to enable/disable other devices
will be straightforward for the new south bridge. (For old
south bridges, it will be harder, and requires one to find all
the bits to set/reset. )
g. Enable the new south bridge to do positive decode by
setting bit 1 of reg. B0h to 1.
h. Set the NOGO signal to low.
i. Program register 42h of PC87200 to 20h. This is a
required initialization step.
j. Program a value of 03 into register D3h of device 1Fh in
function 0 of the new south bridge. This will prevent the
PC87200 from responding to configuration accesses afterwards. The rationale for doing this is to prevent Windows
from detecting two ISA bridges, the other one being the
PCI-to-LPC bridge, and thus creating a conflict. NOTE that
you must connect AD22 to IDSEL of PC87200 for this to
work.
After this, proceed in normal BIOS flow. Note that step d to
j must be performed before ISA bus enumeration, and
therefore before ISA plug and play initialization and option
ROM checking. This is needed for plug and play cards and
15
www.national.com
7.0 Register Descriptions
The 87200 is a single function device. Its register space is The remaining subsections of this chapter is as follows:
called the Bridge Configuration Registers Space (F0) — A brief discussion on how to access the registers located
which is accessed through the PCI interface using the PCI
in the PCI Configuration Space.
Type One Configuration Mechanism.
— Register summary.
The PCI header is a 256-byte region used for configuring a
PCI device or function. The first 64 bytes are the same for — Detailed bit formats of all registers.
all PCI devices and are predefined by the PCI specification. 7.1 Register Summary
These registers are used to configure the PCI for the
The tables in this subsection summarize all the registers of
device. The rest of the 256-byte region is used to configure
the PC87200. Included in the tables are the register’s reset
the device or function itself.
values.
Table 3. Function 0: Bridge Configuration Registers Summary
F0 Index
Width (Bits)
Type
Name
00h-01h
16
RO
Vendor Identification Register
100Bh
02h-03h
16
RO
Device Identification Register
0021h
04h-05h
16
R/W
PCI Command Register
0107h
06h-07h
16
R/W
PCI Status Register
0280h
08h
8
RO
Device Revision ID Register
09h-0Bh
24
RO
PCI Class Code Register
0Ch
8
R/W
PCI Cache Line Size Register
00h
0Dh
8
R/W
PCI Latency Timer Register
00h
0Eh
8
RO
PCI Header Type Register
00h
0Fh
8
RO
PCI BIST Register
00h
10h-3Fh
--
--
Reserved
00h
40h
8
R/W
PCI Function Control Register 1
79h
41h
8
R/W
PCI Function Control Register 2
10h
42h
8
R/W
PCI Function Control Register 3
28h
43h
8
R/W
PCI Function Control Register 4
46h
44h
8
R/W
Reset Control Register
00h
45h-4Fh
--
--
50h
8
R/W
ISA CLK Divider
43h
51h
8
R/W
ISA I/O Recovery Control Register
43h
52h
8
R/W
ROM/AT Logic Control Register
04h
53h-5Ah
--
--
5Bh
8
R/W
5Ch-FFh
--
--
Internal use, do not overwrite
Internal use, do not overwrite
Decode Control Register 2
Internal use, do not overwrite
16
Reset Value
00h
060100h
--
-00h
--
www.national.com
7.0 Register Descriptions (Continued)
7.2 Chipset Register Space
unique to the PC87200. All registers in Function 0 are
directly accessed (i.e., there are no memory or I/O mapped
The Chipset Register Space of the PC87200 is comprised
registers in F0). Table 4 gives the bit formats for these regof one function with PCI header registers. There is no
isters.
memory or I/O mapped register.
IMPORTANT: Register bits marked internal use should
7.2.1 Bridge Configuration Registers - Function 0
not be overwritten, else error will occur.
The register space designated as Function 0 (F0) contains
registers used to configure features and functionality
Table 4. Bridge Configuration Registers
Bit
Description
Index 00h-01h
Vendor Identification Register (RO)
Reset Value = 100Bh
Index 02h-03h
Device Identification Register (RO)
Reset Value =0021h
Index 04h-05h
PCI Command Register (R/W)
Reset Value = 0107h
15:10
Reserved — Set to 0.
9
Fast Back-to-Back Enable (Read Only) — This function is not supported when PC87200 is a master. It is always disabled (must always be set to 0).
8
SERR# — Allow SERR# assertion on detection of special errors: 0 = Disable; 1 = Enable.
7
Wait Cycle Control (Read Only) — This function is not supported in PC87200. It is always disabled (bit is set
to 0).
6
Parity Error — Allow PC87200 to check for parity errors on PCI cycles for which it is a target, and to assert
PERR# when a parity error is detected: 0 = Disable; 1 = Enable.
5
VGA Palette Snoop Enable (Read Only) — This function is not supported in PC87200. It is always disabled
(bit is set to 0).
4
Memory Write and Invalidate —Allow PC87200 to do memory write and invalidate cycles, if the PCI
3
Special Cycles — This function is not supported. It must always be set to 0.
2
Bus Master — Allow PC87200 bus mastering capabilities: 0 = Disable; 1 = Enable. Set this bit to 1.
cache line register is set to 16 bytes (04h). 0=Disable, 1=Enable.
1
Memory Space — Allow PC87200 to respond to memory cycles from the PCI bus: 0 = Disable; 1 = Enable.
PC87200 will only respond to memory cycles destined for the ISA bus as none of its internal functions are
memory-mapped.
0
I/O Space — Allow PC87200 to respond to I/O cycles from the PCI bus: 0 = Disable; 1 = Enable.
Index 06h-07h
PCI Status Register (R/W)
Reset Value = 0280h
15
Detected Parity Error — This bit is set whenever a parity error is detected. Write 1 to clear.
14
Signaled System Error — This bit is set whenever PC87200 asserts SERR# active. Write 1 to clear.
13
Received Master Abort — This bit is set whenever a master abort cycle occurs. A master abort will occur
when a PCI cycle is not claimed, except for special cycles. Write 1 to clear. Register is cleared after RMA is
read.
12
Received Target Abort — This bit is set whenever a target abort is received while the PC87200 is the master
for the PCI cycle. Write 1 to clear.
11
Signaled Target Abort — This bit is set whenever the PC87200 signals a target abort. This occurs when an
address parity error occurs for an address that hits in the active address decode space of the PC87200. Write
1 to clear.
10:9
DEVSEL# Timing — These bits are always 01, as the PC87200 will always respond to cycles for which it is
an active target with medium DEVSEL# timing.
00 = Fast
01 = Medium
10 = Slow
11 = Reserved
17
www.national.com
7.0 Register Descriptions (Continued)
Table 4. Bridge Configuration Registers (Continued)
Bit
8
Description
Data Parity Detected —This bit is set when:
1) The PC87200 asserted PERR# or observed PERR# asserted.
2) PC87200 is the master for the cycle in which the PERR# occurred, and PE is set (F0 Index 04h[6] = 1).
Write 1 to clear.
7
6:0
Fast Back-to-Back Capable — As a target, PC87200 is capable of accepting fast back-to-back transactions:
0 = Disable; 1 = Enable. This bit is always set to 1.
Reserved — Set to 0.
Index 08h
Device Revision ID Register (RO)
Index 09h-0Bh
Index 0Ch
7:0
PCI Class Code Register (RO)
PCI Cache Line Size Register (R/W)
Reset Value = 00h
Reset Value = 060100h
Reset Value = 00h
PCI Cache Line Size Register — reserved.
Index 0Dh
PCI Latency Timer Register (R/W)
Reset Value = 00h
7:4
Reserved — Set to 0.
3:0
PCI Latency Timer Value — The PCI Latency Timer Register prevents system lockup when a slave does not
respond to a cycle that the PC87200 masters. If the value is set to 00h (default), the timer is disabled. If the
timer is written with any other value, bits [3:0] become the four most significant bytes in a timer that counts
PCI clocks for slave response. The timer is reset on each valid data transfer. If the counter expires before the
next assertion of TRDY# is received, the PC87200 stops the transaction with a master abort and asserts
SERR#, if enabled to do so.
Index 0Eh
7:0
PCI Header Type (RO)
PCI Header Type Register — This.register defines the format of this header. This header is of type format 0.
Additionally, bit 7 defines whether this PCI device is a multifunction device (bit 7 = 1) or not (bit 7 = 0).
Index 0Fh
7:0
Reset Value =00h
PCI BIST Register (RO)
Reset Value = 00h
Reserved
Reset Value = 00h
PCI Function Control Register 1 (R/W)
Reset Value = 79h
Reserved. Set to 0.
Index 10h-3Fh
Index 40h
7
Internal use, do not overwrite.
6
Single Write Mode — PC87200 accepts only single cycle write transfers as a slave on the PCI bus and performs a target disconnect with the first data transferred: 0 = Disable (accepts burst write cycles); 1 = Enable.
5
Single Read Mode — PC87200 accepts only single cycle read transfers as a slave on the PCI bus and performs a target disconnect with the first data transferred. 0 = Disable (accepts burst read cycles); 1 = Enable.
4
Retry PCI Cycles — Retry inbound PCI cycles if data is buffered and waiting to go outbound on PCI:
0 = No Retry; 1 = Retry.
3
Write Buffer — PCI slave write buffer: 0 = Disable; 1 = Enable.
2:1
0
Reserved- set to 0.
BS8/16 — This bit can not be written. Always = 1.
Note: Bits 6 and 5 emulate the behavior of first generation devices developed for PCI.
18
www.national.com
7.0 Register Descriptions (Continued)
Table 4. Bridge Configuration Registers (Continued)
Bit
Description
Index 41h
PCI Function Control Register 2 (R/W)
Reset Value = 10h
7
Burst to Beat — Bursts are converted to single beats for X-Bus to PCI bus reads: 0 = Disable; 1 = Enable.
6
Internal use, do not overwrite
5
PERR# Signals SERR# — Assert SERR# any time that PERR# is asserted or detected active by the
PC87200 (allows PERR# assertion to be cascaded to NMI (SMI) generation in the system): 0 = Disable; 1 =
Enable.
4
Write Buffer Enable — Allow 16-byte buffering for X-Bus to PCI bus writes: 0 = Disable; 1 = Enable.
3
Internal use, do not overwrite.
2:1
Subtractive Decode — These bits determine the point at which the PC87200 accepts cycles that are not
claimed by another device. The PC87200 defaults to taking subtractive decode cycles in the default cycle
clock, but can be moved up to the Slow Decode cycle point if all other PCI devices decode in the fast or medium clocks. Disabling subtractive decode must be done with care, as all ISA and ROM cycles are decoded
subtractively.
00 = Default sample (4th clock from FRAME# active)
01 = Slow sample (3rd clock from FRAME# active)
1x = No subtractive decode
0
Internal use, do not overwrite.
Index 42h
PCI Function Control Register 3 (R/W)
Reset Value = 28h
7
Internal use, do not overwrite
6
Internal use, do not overwrite.
5
Delayed Transactions — Allow delayed transactions on the PCI bus: 0 = Disable; 1 = Enable.
4
Internal use, do not overwrite.
3
No X-Bus ARB, Buffer Enable — When PC87200 is a PCI target, allow buffer PCI transactions without X-Bus
arbitration: 0 = Disable; 1 = Enable.
2
Internal use, do not overwrite.
1
Internal use, do not overwrite.
0
Internal use, do not overwrite.
Index 43h
PCI Function Control Register 4
Reset Value = 46h
7
Reserved — Set to 0.
6
Internal use, do not overwrite.
5
Internal use, do not overwrite.
4
Internal use, do not overwrite.
3
Internal use, do not overwrite.
2
Internal use, do not overwrite.
1
PCI Retry Cycles — When PC87200 is a PCI target and the PCI buffer is not empty, allow PCI bus to retry
cycles:
0 = Disable; 1 = Enable.
This bit works in conjunction with PCI bus delayed transactions bit. F0 Index 42h[5] must = 1 for this bit to be
valid.
0
Index 44h
7
Internal use, do not overwrite.
Reset Control Register (R/W)
Reset Value = 00000000b
Internal use, do not overwrite.
19
www.national.com
7.0 Register Descriptions (Continued)
Table 4. Bridge Configuration Registers (Continued)
Bit
Description
6
Internal use, do not overwrite.
5
Internal use, do not overwrite.
4
Internal use, do not overwrite.
3
Internal use, do not overwrite.
2
Internal use, do not overwrite.
1
Internal use, do not overwrite.
0
X-Bus Warm Start
Write only: 0 = NOP; 1 = Execute system wide reset (used only for clock configuration at power-up)
Index 45h-4Fh
Internal use, do not overwrite
Index 50h
ISA CLK Divider (R/W)
7
Internal use, do not overwrite.
6
Internal use, do not overwrite.
5
Internal use, do not overwrite.
4
Internal use, do not overwrite.
3
Internal use, do not overwrite.
2:0
Reset Value = 43h
ISA Clock Divisor — Determines the divisor of the PCI clock used to generate the ISA bus clock:
010 = Divide by three (ISA clock = 11MHz)
011 = Divide by four (ISA clock = 8.33 MHz)
All other values are invalid and can produce unexpected results.
Index 51h
7:4
ISA I/O Recovery Control Register (R/W)
Reset Value = 43h
8-Bit I/O Recovery — These bits determine the number of ISA bus clocks between back-to-back 8-bit I/O read
cycles. This count is in addition to a preset one-clock delay built into the controller.
0000 = 1 PCI clock1101 = 14 PCI clocks
0001 = 2 PCI clocks1110 = 15 PCI clocks
:::1111 = 16 PCI clocks
3:0
16-Bit I/O Recovery — These bits determine the number of ISA bus clocks between back-to-back 16-bit I/O
cycles. This count is in addition to a preset one-clock delay built into the controller.
0000 = 1 PCI clock1101 = 14 PCI clocks
0001 = 2 PCI clocks1110 = 15 PCI clocks
:::1111 = 16 PCI clocks
Index 52h
ROM Control Register (R/W)
Reset Value = 04h
7
Internal use, do not overwrite.
6
Internal use, do not overwrite.
5
Internal use, do not overwrite.
4
Internal use, do not overwrite.
3
Internal use, do not overwrite.
2
ROM 1MB Enable — Allow addressing to 512K or 1MB ROM (FFF00000h-FFFFFFFFh):
0 = Disable; 1 = Enable.
1
Internal use, do not overwrite.
0
Internal use, do not overwrite.
20
www.national.com
7.0 Register Descriptions (Continued)
Table 4. Bridge Configuration Registers (Continued)
Bit
Description
Index 53h-5Ah
Index 5Bh
Internal use, do not overwrite
Decode Control Register 2 (R/W)
Reset Value = 00h
7
Internal use, do not overwrite.
6
Reserved — Set to 0.
5
BIOS ROM Positive Decode — Selects positive or subtractive decoding for accesses to the configured ROM
space:
0 = Subtractive; 1 = Positive.
4
Internal use, do not overwrite.
3
Internal use, do not overwrite.
2
Internal use, do not overwrite.
1
Internal use, do not overwrite.
0
Internal use, do not overwrite.
Note: Positive decoding by the PC87200 speeds up the I/O cycle time.
Index 5Ch-FFh
Internal use, do not overwrite
21
www.national.com
8.0 Electrical Characteristics
8.1 Electrical Specifications
This section provides information on testing modes, electrical connections, absolute maximum ratings, recommended
operating conditions, and DC/AC characteristics. All voltage values in Electrical Specifications are with respect to VSS
unless otherwise noted.
For detailed information on the PCI bus electrical specification refer to Chapter 4 of the PCI Bus Specification,
Revision 2.1.
8.2 PC87200 Test Modes
The PC87200 can be forced into different test modes. The following table summarizes the test mode selection process.
Table 5. Test mode selection
Mode
Signal Name
PCIRST#
BALE during reset
Reserved
x
0
IRQ3 IRQ4 IRQ5 IRQ6 IRQ7
0
1
0
0
1
NAND tree test
x
0
x
x
x
x
0
Reserved
x
0
1
0
0
0
1
Reserved
x
0
1
1
0
0
1
Reserved
x
0
1
1
1
0
1
Reserved
x
0
0
0
0
1
1
SCAN_MODE = 1, SCAN_ENABLE = 0,
x
0
1
0
0
1
1
SCAN_MODE = 1, SCAN_ENABLE = 1,
X-BUS_DISABLE = 1
x
0
1
0
1
1
1
Note: x = Don’t Care
22
www.national.com
8.0 Electrical Characteristics (Continued)
8.2.1 Test Mode Logic
This block will produce various test mode signals for different test modes :
— XBus test signal
— Test mode signal
— Scan mode signal
— NAND test signal
0
test_in
pad_bale_in
1
pad_pcirstx_in
x_clk
irq3
irq4
irq6
irq7
test_in
scan_mode
irq3
irq4
irq5
irq6
test_in
xbus_test
irq3
irq4
irq5
irq6
test_in
test_mode
pad_pcirstx_in
Test signal generation logic
23
www.national.com
8.0 Electrical Characteristics (Continued)
DRV is the final output. BALE, PCIRSTX and IRQ7 are not
included in the NAND chain because they are required to
During NAND tree testing, all outputs and bi-directional
put the chip to NAND test mode. The NAND tree connecpins will be tri-stated except BALE and RSTDRV pins. The
tion is as shown below.
first input of the NAND chain is SA18. The NAND chain is
routed counter-clockwise around the chip (eg. SA18,
SA19, IRQ9, ...). TC is the intermediate output and RST8.2.2 NAND Tree Connections
SA18
SA19
xdma_tc
0
TC
1
SBHEX
nand_test_en
BPDX
~pad_pcirstx_in
SA16
0
RSTDRV
1
SA17
nand_test_en
test_in
irq7
nand_test_en
NAND Tree Diagram
24
www.national.com
8.0 Electrical Characteristics (Continued)
8.2.3 NAND Tree Order
Note
Pin #
Pin Name
Pin #
Pin Name
37
IRQ15
1
VDD
38
IRQ14
2
VSS
39
VDD
3
SA18
40
VSS
4
SA19
41
DACK0#
5
IRQ9
42
DREQ0
6
DACK2#
43
MEMR#
7
DREQ2
44
MEMW#
8
SYSCLK
45
DACK5#
9
SD7
46
DREQ5
10
SD6
47
SD8
11
SD5
48
SD9
12
SD4
49
SD10
13
IOCHK#
50
SD11
14
REFRESH#
51
DACK6#
15
SD3
52
DREQ6
16
SD2
53
SD12
17
SD1
54
SD13
18
SD0
55
SD14
19
VDD
56
SD15
20
VSS
57
DACK7#
21
IOCHRDY
58
DREQ7
22
SMEMR#
59
VDD
23
AEN
60
VSS
24
SMEMW#
61
MASTER#
25
IOR#
62
SBHE#
26
IOW#
63
TC
27
BALE
64
BPD#
65
AD31
28
MEMCS16#
66
AD30
29
IOCS16#
67
AD29
30
SA20
68
AD28
31
SA21
69
AD27
32
SA22
70
AD26
33
SA23
71
VDD
43
IRQ10
72
VSS
35
IRQ11
73
AD25
36
IRQ12
first input in NAND chain
not in NAND chain
(see Timing Diagram)
25
Note
intermediate NAND chain output
www.national.com
8.0 Electrical Characteristics (Continued)
Pin #
Pin Name
74
Note
Pin #
Pin Name
AD24
111
AD7
75
C/BE3#
112
AD6
76
IDSEL
113
VDD
77
AD23
114
VSS
78
AD22
115
AD5
79
VDD
116
AD4
80
VSS
117
AD3
81
AD21
118
AD2
82
AD20
119
AD1
83
AD19
120
AD0
84
AD18
121
VDD
85
AD17
122
VSS
86
AD16
123
PCICLK
87
C/BE2#
124
PCIRST#
88
FRAME#
89
VDD
125
PCPCIREQ#
90
VSS
126
PCPCIGNT#
91
IRDY#
127
SERIRQ
92
TRDY#
128
IRQ3
93
DEVSEL#
129
IRQ4
94
STOP#
130
IRQ5
95
SERR#
131
IRQ6
96
PAR
132
IRQ7
97
VDD
98
VSS
133
DACK3#
99
C/BE1#
143
DREQ3
100
AD15
135
RSTDRV
101
AD14
136
DACK1#
102
AD13
137
DREQ1
103
AD12
138
PROHIBIT
104
AD11
139
VDD
105
VDD
140
VSS
106
VSS
141
SA0
107
AD10
142
SA1
108
AD9
143
SA2
109
AD8
144
SA3
110
C/BE0#
145
SA4
146
SA5
26
Note
(see Timing Diagram)
not in NAND chain
(see Timing Diagram)
floating, not in NAND chain
not in NAND chain
(see Timing Diagram)
NAND chain output
www.national.com
8.0 Electrical Characteristics (Continued)
Pin #
Pin Name
147
SA6
148
SA7
149
SA8
150
VDD
151
VSS
152
SA9
153
SA10
154
SA11
155
SA12
156
SA13
157
SA14
158
SA15
159
SA16
160
SA17
Note
end of NAND chain
Note 1: All Vdd and Vss are not in the NAND chain.
27
www.national.com
8.0 Electrical Characteristics (Continued)
in the NAND chain should be pulled high. Then release
PCIRST#. After PCIRST# goes inactive, starting with
Set PCIRST#, BALE and IRQ7 to low (PCPCIREQ# SA18 going counter-clockwise, switch each pin in the
should be left floating), toggle PCICLK (provide a low-to- NAND chain low at a rate of at least about 100ns apart.
high transition) at least once (recommended to provide
two edges as show in the diagram below). All other pins
8.2.4 Timing Diagram for NAND test
PCIRST#
BALE, IRQ7 - stay low
PCICLK
t
t
t
2t
SA18
t
t
SA19
t
IRQ9
AD0
PCPCIGNT#
t
RSTDRV
Note : t >= 100ns
28
www.national.com
8.0 Electrical Characteristics (Continued)
8.3 Electrical Connections
effects. These effects can be minimized by filtering the DC
power leads with low-inductance decoupling capacitors,
8.3.5 Unused Input Pins
using low-impedance wiring, and by utilizing all of the VDD
All inputs not used by the system designer should be kept and GND pins.
at either ground or VDD. To prevent possible spurious oper8.4 Absolute Maximum Ratings
ation, connect active-high inputs to ground through a 20kohm ( 10%) pull-down resistor and active-low inputs to Table 6. lists absolute maximum ratings for the PC87200.
Stresses beyond the listed ratings may cause permanent
VDD through a 20-kohm ( 10%) pull-up resistor.
damage to the device. Exposure to conditions beyond these lim8.3.6 NC-Designated Pins
its may (1) reduce device reliability and (2) result in premaPins designated NC should be left disconnected. Connect- ture failure even when there is no immediately apparent
ing an NC pin to a pull-up resistor, pull-down resistor, or an sign of failure. Prolonged exposure to conditions at or near
active signal could cause unexpected results and possible the absolute maximum ratings may also result in reduced
circuit malfunctions.
useful life and reliability These are stress ratings only and
8.3.7 Power and Ground Connections and Decoupling do not imply that operation under any conditions other than
those listed under Table 7. is possible.
Testing and operating the PC87200 requires the use of
standard high frequency techniques to reduce parasitic
Table 6. Absolute Maximum Ratings
Parameter
Min
Operating Case Temperature
Storage Temperature
–65
Supply Voltage
Voltage On Any Pin:
–0.5
Max
Units
110
˚C
150
˚C
4.0
V
5.5
V
Comment
No Bias
8.5 Recommended Operating Conditions
Table 7. lists the recommended operating conditions for the
PC87200.
Table 7. Recommended Operating Conditions
Symbol
Parameter
TA
Ambient Temperature
VDD
Supply Voltage
Min
Max
Units
0
70
˚C
3.0
3.6
V
29
Comment
3.3 V nominal
www.national.com
8.0 Electrical Characteristics (Continued)
8.6 DC Characteristics
Table 8. DC Characteristics (at Recommended Operating Conditions)
Symbol
Parameter
Min
Typ
Max
Units
Comment
ISA bus (including PROHIBIT, BPD#)
VIL
Input Low Voltage
–0.5
0.8
V
TTL Level Inputs
VIH
Input High Voltage
2.0
VDD+0.5
V
TTL Level Inputs
VOL
Output Low Voltage
0.5
V
Iol=12 mA
VOH
Output High Voltage
V
Ioh=-3mA
IOHL
Output High Leakage
200
uA
Vo=Vcc, for OD driver
2.4
PCI bus (including PCPCIREQ#, PCPCIGNT#, SERIRQ)
VILC
Input Low Voltage
–0.5
0.3VDD
V
CMOS Level Inputs
VIHC
Input High Voltage
0.5VDD
VDD+0.5
V
CMOS Level Inputs
VOLC
Output Low Voltage
0.1VDD
V
Iout=1500uA
VOHC
Output High Voltage
V
Iout=-500uA
0 < VIN < VDD,
0.9VDD
All pins
II
Input Leakage Current for each
input pin
15
A
CIN
Input Capacitance
10
pF
f = 1MHz
COUT
Output or I/O Capacitance
10
pF
f = 1MHz
CCLK
CLK Input Capacitance
10
pF
f = 1MHz
160
mA
Current Consumption
ICC
Active ICC: PCICLK @ 33 MHz
30
ICCSS
Standby ICC (PCICLK Stopped)
10
30
uA
fPCICLK = 0MHz
www.national.com
8.0 Electrical Characteristics (Continued)
8.7 AC Characteristics
The following tables list the AC characteristics including output delays, input setup requirements, input hold requirements
and output float delays. The rising-clock-edge reference level VREF, and other reference levels are shown in Table 9.
Input or output signals must cross these levels during testing.
Input setup and hold times are specified minimums that define the smallest acceptable sampling window for which a synchronous input signal must be stable for correct operation.
Note: All AC tests are at VDD = 3.0V to 3.6V,
TA = 0oC to 70oC, CL = 50pF unless otherwise specified.
Table 9. Drive Level and Measurement Points for Switching Characteristics
Symbol
Voltage (V)
VREF
1.5
VIHD
2.3
VILD
0.3
TX
CLK
VIHD
VREF
VILD
A
B
Max
Min
Valid Output n+1
Valid Output n
OUTPUTS
C
INPUTS
VIHD
VREF
D
Valid Input
VILD
VREF
Legend: A = Maximum Output Delay Specification
B = Minimum Output Delay Specification
C = Minimum Input Setup Specification
D = Minimum Input Hold Specification
Figure 4. Drive Level and Measurement Points for Switching Characteristics
Table 10. AC Characteristics of Specification Compliant Interface Signals
Interface Signal Group
Specification Name
PCI Bus Interface Signals
PCI Bus Specification, Revision 2.1
ISA Bus Interface Signals
Abides industry standards
The interface signal groups listed in Table 11. adhere to the timing parameters given in the corresponding specification.
For details, refer to those specifications.
31
www.national.com
8.0 Electrical Characteristics (Continued)
Table 11. Clock Characteristics
Symbol
Parameter
Min
Max
∞
Duty
Cycle
Unit
Comment
Input Signal
tcyc
PCICLK Cycle Time
30
ns
tHIGH
PCICLK High Time
11
ns
tLOW
PCICLK Low Time
11
ns
--
PCICLK Slew Time
1
4
V/ns
Note 1
Note 1: Rise and fall times are specified in terms of the edge rate measured in V/ns. This slew rate must be met across the minimum peak-to-peak
portion of the clock waveform as shown in Figure 5..
tcyc
tHIGH
0.6 VCC
tLOW
0.5 VCC
0.4 VCC
0.4 VCC, p-to-p
(minimum)
0.3 VCC
0.2 VCC
Figure 5. PCICLK Waveform
32
www.national.com
PC87200 PCI to ISA Bridge
9.0 Physical Dimensions inches (millimeters) unless otherwise noted
160 Lead Molded Plastic Quad Flat Package (JEDEC)
Order Number PC87200160A
NS Package Number VUL160A
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably
expected to result in a significant injury to the user.
National Semiconductor
Corporation
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Email: [email protected]
National Semiconductor
Europe
Fax:
(+49) 0-180-530 85 86
Email: [email protected]
Deutsch Tel:
(+49) 0-180-530 85 85
English Tel:
(+49) 0-180-532 78 32
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
National Semiconductor
Asia Pacific
Customer Response Group
Tel: 65-254-4466
Fax: 65-250-4466
Email: [email protected]
National Semiconductor
Japan Ltd.
Tel: 81-3-5620-6175
Fax: 81-3-5620-6179
www.national.com
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.