GX1 Datasheet, PDF (170/247 Pages) National Semiconductor (TI) – Processor Series Low Power Integrated x86 Solution

Integrated Functions (Continued)
Bit
Name
Index 00h-01h
31:0
VID (RO)
Index 02h-03h
31:0
DIR (RO)
Index 04h-05h
15:10
9
RSVD
FBE
8
SERR
7
WAT
6
PE
5
VPS
4
MS
3
SPC
2
BM
1
MS
0
IOS
Index 06h-07h
15
DPE
14
SSE
13
RMA
12
RTA
11
STA
Table 4-44. PCI Configuration Registers
Description
Vendor Identification Register (RO)
Default Value = 1078h
Vendor Identification register (Read Only): The combination of this value and the device ID uniquely
identifies any PCI device. The Vendor ID is the ID given to National Semiconductor Corporation by the
PCI SIG.
Device Identification Register (RO)
Default Value = 0001h
Device Identification register (Read Only): This value along with the vendor ID uniquely identifies any
PCI device.
PCI Command Register (R/W)
Default Value = 0007h
Reserved: Set to 0.
Fast Back-to-Back Enable (RO): As a master, the GX1 processor does not support this function.
This bit returns 0.
SERR# Enable: This is used as an output enable gate for the SERR# driver.
Wait Cycle Control: GX1 processor does not do address/data stepping.
This bit is always set to 0.
Parity Error Response:
0 = GX1 processor ignores parity errors on the PCI bus.
1 = GX1 processor checks for parity errors.
VGA Palette Snoop: GX1 processor does not support this function.
This bit is always set to 0.
Memory Write and Invalidate Enable: As a master, the GX1 processor does not support this function.
This bit is always set to 0.
Special Cycles: GX1 processor does not respond to special cycles on the PCI bus.
This bit is always set to 0.
Bus Master:
0 = GX1 processor does not perform master cycles on the PCI bus.
1 = GX1 processor can act as a bus master on the PCI bus.
Memory Space: GX1 processor will always respond to memory cycles on the PCI bus.
This bit is always set to 1.
I/O Space: GX1 processor will not respond to I/O accesses from the PCI bus.
This bit is always set to 1.
PCI Device Status Register (RO, R/W Clear)
Default Value = 0280h
Detected Parity Error: When a parity error is detected, this bit is set to 1.
This bit can be cleared to 0 by writing a 1 to it.
Signaled System Error: This bit is set whenever SERR# is driven active.
Received Master Abort: This bit is set whenever a master abort cycle occurs. A master abort will occur
whenever a PCI cycle is not claimed except for special cycles.
This bit can be cleared to 0 by writing a 1 to it.
Received Target Abort: This bit is set whenever a target abort is received while the GX1 processor is
master of the cycle.
This bit can be cleared to 0 by writing a 1 to it.
Signaled Target Abort: This bit is set whenever the GX1 processor signals a target abort. A target abort
is signaled when an address parity occurs for an address that hits in the GX1 processor’s address space.
This bit can be cleared to 0 by writing a 1 to it.
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