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ISA Local Resource Bus
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1-31
1
Note
The direction and the polarity of the Z8536’s port pins are
software programmable.
Two Wire Serial (I
2
C) Bus Controller
The I
2
C bus controller controls communication with the DRAM DIMM
on-module EEPROM devices. The EEPROM devices contain the Serial
Presence Detect information (see section on System Memory for more
information). Refer to the PCF8584 data sheet for additional programming
information. The DIMM EEPROM addresses on the two wire serial bus
are shown in
.
PB5
DTR4_
Output
Port 4 Data Terminal Ready
PB6
Reserved
I/O
Reserved
PB7
ABORT_
Input
Status of ABORT# signal
PC0
Reserved
I/O
Reserved
PC1
Reserved
I/O
Reserved
PC2
Reserved
I/O
Reserved
PC3
Reserved
I/O
Table 1-19. I
2
C Controller Access Registers
PCI I/O Address
Function
0000 0980
Operation Registers
0000 0981
Control/Status Register
Table 1-18. Z8536 CIO Port Pins Assignment (Continued)
Port Pin
Signal Name
Direction
Descriptions