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Avago Technologies LSI8751D User Manual

Page 78

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3-14

PCI Functional Description

R

Reserved

[15:9]

SERR/ Enable

8

This bit enables the SERR/ driver. SERR/ is disabled
when this bit is cleared. The default value of this bit is
zero. This bit and bit 6 must be set to report address
parity errors.

R

Reserved

7

Enable Parity Error Response

6

This bit allows the LSI53C875 to detect parity errors on
the PCI bus and report these errors to the system. Only
data parity checking is enabled. The LSI53C875 always
generates parity for the PCI bus.

R

Reserved

5

WIE

Write and Invalidate Mode

4

This bit allows the LSI53C875 to generate memory write
and invalidate commands on the PCI bus. The WIE bit in
the DMA Control (DCNTL) register must also be set for
the device to generate Write and Invalidate commands.
For more information on these conditions, refer to the
section

Section 3.2.5, “Memory Write and Invalidate

Command.”

To enable Write and Invalidate Mode, set

bit 0 in the

Chip Test Three (CTEST3)

register (operating

register set).

R

Reserved

3

EBM

Enable Bus Mastering

2

This bit controls the ability of the LSI53C875 to act as a
master on the PCI bus. A value of zero disables this
device from generating PCI bus master accesses. A
value of one allows the LSI53C875 to behave as a bus
master. The LSI53C875 must be a bus master in order
to fetch SCRIPTS instructions and transfer data.

EMS

Enable Memory Space

1

This bit controls the ability of the LSI53C875 to respond
to Memory Space accesses. A value of zero disables the
device response. A value of one allows the LSI53C875 to
respond to Memory Space accesses at the address spec-
ified by

Base Address One (Memory)

.

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