CS4281 Programming Manual
DS308PRM1
136
Confidential Draft
3/7/00
14.1.2
PC/PCI Grant Register (PCPGR)
Address:
BA0: 604h, Read-Only
Default:
0000h
Definition: Provided for debug purposes only and is the grant status of the PC/PCI interface.
Bit Descriptions:
GDC[2:0] Granted DMA Engine: These bits are the encoded DMA engine number taken directly from
the PC/PCI grant signal. No value over 3 should ever be received from the host PC/PCI DMA
engine.
0 0 0 = DMA engine 0 (reset default)
0 0 1 = DMA engine 1
0 1 0 = DMA engine 2
0 1 1 = DMA engine 3
1 0 1 = DMA engine 5
1 1 0 = DMA engine 6
1 1 1 = DMA engine 7
VL
Valid: This bit indicates whether or not the
GDC[2:0]
bits contain valid information. The
PC/PCI engine automatically sets this bit to 1 when it receives a grant from the host PC/PCI
agent, and the PC/PCI engine automatically clears
VL
when a DMA transfer completes or is
terminated.
14.1.3
PC/PCI Control Register (PCPCR)
Address:
BA0: 608h, Read-Write
Default:
0000h
Definition: Master enable for the PC/PCI logic. BIOS sets the PC/PCI flag in the config space, CFLR register
at boot time. Host configuration software, seeing the PC/PCI flag set, should enable the PC/PCI
logic via this register and set the IOTPCP PCI trapping register and set the legacy mode to
PC/PCI,
IOTCR.EDMA[1:0]
= 10.
Bit Descriptions:
PCPEN
PC/PCI Enable: Setting this bit to 1 enables the PC/PCI logic and enables the
PCREQ#
and
PCGNT#
pins for PC/PCI functions (as opposed to EEPROM or GPIO functions).
0 = PC/PCI disabled (reset default)
1 = PC/PCI enabled
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VL
GDC2
GDC1
GDC0
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PCPEN
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