4-2
Service Manual PRELIMINARY
4.1
Using Error Logs
Error detection is performed by CPUs, the IOD, and the EISA to PCI bus
bridge. (The IOD is the acronym used by software to refer to the system bus to
PCI bus bridge.)
Figure 4-1 Error Detector Placement
ECC
ECC
CPU Chip
Data
System Bus
System Bus
Comd/add
B-cache
Duplicate Tag
EISA Bus
Bridge
Sys/PCI
Bus Bridge
P
P
P
P
ECC
Parity logic
ECC logic
P
EISA
PCI
PKW0450-96
Tag & Status
Tag & Status
Data
CPU Module
X
C
V
R
Memory
PS
PS
PS
PS
ECC
S
ECC
S
ECC
S
Parity stored
ECC stored
