82845PE Datasheet, PDF (78/176 Pages) Intel Corporation – 82845GE Graphics and Memory Controller Hub (GMCH) and 82845PE Memory Controller Hub (MCH)

Register Description
3.5.2.4
3.5.2.5
PCISTS1—PCI Status Register (Device 1)
Address Offset:
Default Value:
Access:
Size:
06–07h
00A0h
RO, R/WC
16 bits
PCISTS1 is a 16-bit status register that reports the occurrence of error conditions associated with
primary side of the “virtual” PCI-to-PCI bridge embedded within the (G)MCH.
Bit
Description
15
Detected Parity Error (DPE)—RO. Hardwired to 0. Parity is not supported on the primary side of
this device.
Signaled System Error (SSE)—R/WC.
0 = Software clears this bit by writing a 1 to it.
14 ^{1 = This bit is set to 1 when (G)MCH Device 1 generates an SERR message over the hub interface}
for any enabled Device 1 error condition. Device 1 error conditions are enabled in the
ERRCMD, PCICMD1 and BCTRL1 registers. Device 1 error flags are read/reset from the
ERRSTS and SSTS1 register.
13
Received Master Abort Status (RMAS)—RO. Hardwired to 0. The concept of a master abort does
not exist on primary side of this device.
12
Received Target Abort Status (RTAS)—RO. Hardwired to 0. The concept of a target abort does
not exist on primary side of this device. T
11
Signaled Target Abort Status (STAS)—RO. Hardwired to 0. The concept of a target abort does not
exist on primary side of this device.
DEVSEL# Timing (DEVT)—RO. Hardwired to 00. The (G)MCH does not support subtractive
10:9 decoding devices on bus 0. This bit field is therefore hardwired to 00 to indicate that Device 1 uses
the fastest possible decode.
8
Data Parity Detected (DPD)—RO. Hardwired to 0. Parity is not supported on the primary side of
this device.
7
Fast Back-to-Back (FB2B)—RO. Hardwired to 1. This indicates that the AGP/PCI_B interface
always supports fast back to back writes.
6 Reserved.
5 66/60MHz Capability (CAP66)—RO. Hardwired to 1. The AGP/PCI bus is 66 MHz capable.
4:0 Reserved.
RID1—Revision Identification Register (Device 1)
Address Offset:
Default Value:
Access:
Size:
08h
See table below
RO
8 bits
This register contains the revision number of the (G)MCH Device 1.
Bit
Description
Revision Identification Number (RID). This is an 8-bit value that indicates the revision identification
number for the (G)MCH Device 1.
82845GE GMCH
7:0
03h = B1 Stepping
82845PE MCH
02h = B0 Stepping
78
Intel^® 82845GE/82845PE Datasheet