4-44
Service Manual PRELIMINARY
4.4.1
System Bus ECC Error
Step 2
Read the MC_ERR1 register and match the contents with the data pattern. Perform
the action indicated.
Table 4-4 System Bus ECC Error Data Pattern
MC_ERR1 Data Pattern
Most Likely Cause
Action
for Memory Read
1000 0000 0000 xxxx xxxx 10xx 0xxx xxxx
Bad nondirty data from
memory (bad memory)
Go to Step 10
1000 0000 0000 xxxx xxxx 111x 0xxx xxxx
Bad nondirty data from
memory (bad memory)
Go to Step 10
1000 0000 0001 xxxx xxxx 10xx 0xxx xxx
Bad dirty data from a
CPU
Replace CPU(s)
1000 0000 0001 xxxx xxxx 111x 0xxx xxxx
Bad dirty data from a
CPU
Replace CPU(s)
for Memory or I/O Write
1000 0000 000x xxx0 10xx 011x xxxx xxxx
Bad data from MID = 2
Replace CPU0
1000 0000 000x xxx0 11xx 011x xxxx xxxx
Bad data from MID = 3
Replace CPU1
1000 0000 000x xxx1 00xx 011x xxxx xxxx
Bad data from MID = 4
Replace IOD0
1000 0000 000x xxx1 01xx 011x xxxx xxxx
Bad data from MID = 5
Replace IOD0
1000 0000 000x xxx1 10xx 011x xxxx xxxx
Bad data from MID = 6
Replace CPU2
or IOD1
1000 0000 000x xxx1 11xx 011x xxxx xxxx
Bad data from MID = 7
Replace CPU3
or IOD1
for Memory Fill Transactions
1000 0000 000x xxx1 00xx 110x xxxx xxxx
Bad data from MID = 4
Replace IOD0
1000 0000 000x xxx1 01xx 110x xxxx xxxx
Bad data from MID = 5
Replace IOD0
1000 0000 000x xxx1 10xx 110x xxxx xxxx
Bad data from MID = 6
Replace IOD1
1000 0000 000x xxx1 11xx 110x xxxx xxxx
Bad data from MID = 7
Replace IOD1
NOTE: IOD0 = B3040-AA bridge module; IOD1 = B3040-AB bridge module.
