PCI Configuration Registers
A-5
Register Definitions

Should autoconfiguration fail (bad checksum), this register is loaded with the

ThunderLAN device ID of 0500h.

A.1.4 PCI Command Register (@ 04h)

En
I/O
En
Mem
En
BM
Reserved
En
Par
En
SER
Reserved
0123456789101112131415
Res
Table A–1. PCI Command Register Bits
Bit Name Function
15–9 Reserved Writes to these bits are ignored; bits are always read as 0.
8 SER_En PSERR# driver enable: A value of 1 enables the adapter PSERR# driver. A value of
0 disables the driver.
7 Reserved Writes to this bit are ignored; bit is always read as 0.
6 PAR_En Parity enable: Enables the adapter PCI parity checking. A value of 1 allows the adapter
to check PCI parity, a value of 0 causes PCI parity errors to be ignored.
5– 3 Reserved Writes to these bits are ignored; bits are always read as 0.
2 BM_En Bus master enable: Enables the adapter as a PCI bus master. A value of 1 enables bus
master operations, a value of 0 disables them.
1 Mem_En Memory enable: Enables memory-mapped accesses to the adapter. A value of 0 dis-
ables response to memory-mapped accesses. A value of 1 enables response to
memory-mapped accesses.
0I/O_En I/O Enable: Enables I/O mapped accesses to the adapter. A value of 0 disables re-
sponse to I/O accesses. A value of 1 enables response to I/O accesses.