SECTION 4
PCI 9080
REGISTERS
PLX Technology, Inc., 1997
Page 76
Version 1.02
4.5.12 (CNTRL; PCI:6Ch, LOC:ECh) Serial EEPROM Control, PCI Command Codes, User I/O
Control, Init Control Register
Table 4-59. (CNTRL; PCI:6Ch, LOC:ECh) Serial EEPROM Control, PCI Command Codes, User I/O Control, Init
Control Register
Field
Description
Read
Write
Value after Reset
3:0
PCI Read Command Code for DMA. This PCI command is sent out during DMA
read cycles.
Yes
Yes
1110
7:4
PCI Write Command Code for DMA. This PCI command is sent out during DMA
write cycles.
Yes
Yes
0111
11:8
PCI Memory Read Command Code for Direct Master. This PCI command is sent
out during Direct Master read cycles.
Yes
Yes
0110
15:12
PCI Memory Write Command Code for Direct Master. This PCI command is sent
out during Direct Master write cycles.
Yes
Yes
0111
16
General Purpose Output. Value of 1 causes USERO output to go high. Value of 0
causes USER0 output to go low.
Yes
Yes
1
17
General Purpose Input. Value of 1 indicates USERI input pin is high. Value of 0
indicates USERI pin is low.
Yes
No
—
23:18
Reserved.
Yes
No
0
24
Serial EEPROM Clock for Local or PCI Bus Reads or Writes to serial EEPROM.
Toggling this bit generates a serial EEPROM clock. (Refer to the manufacturer’s
data sheet for the particular serial EEPROM being used.)
Yes
Yes
0
25
Serial EEPROM Chip Select. For local or PCI bus reads or writes to serial
EEPROM, setting this bit to 1 provides the serial EEPROM chip select.
Yes
Yes
0
26
Write Bit to serial EEPROM. For writes, this output bit is the input to the serial
EEPROM. Clocked into the serial EEPROM by the serial EEPROM clock.
Yes
Yes
0
27
Read serial EEPROM Data Bit. For reads, this input bit is the output of the serial
EEPROM. Clocked out of the serial EEPROM by the serial EEPROM clock.
Yes
No
—
28
Serial EEPROM Present. Value of 1 indicates a serial EEPROM is present.
Yes
No
0
29
Reload Configuration Registers. When this bit is set to 0, writing a 1 causes PCI
9080 to reload the local configuration registers from serial EEPROM.
Yes
Yes
0
30
PCI Adapter Software Reset. Value of 1 holds the local bus logic in the PCI 9080
reset and LRESETo# asserted. The contents of the PCI configuration registers and
Shared Run Time registers will not be reset. Software Reset can only be cleared
from the PCI bus. (Local bus remains reset until this bit is cleared.)
Yes
Yes
0
31
Local Init Status. Value of 1 indicates Local Init done. Responses to PCI accesses
are RETRYs until this bit is set. While input pin NB# is asserted low, this bit is
forced to 1.
Yes
Yes
0