Dimm Isolation Procedure; Determining The Real Failed Array For 4-Way Interleaving; Determining The Real Failed Array For 2-Way Interleaving - Compaq AlphaServer ES45 Service Manual

E.2

DIMM Isolation Procedure

Use the procedure in this section to isolate the failing DIMM.
1. Find the failing array by using the failing address and the Array Address
Registers (AARs—see Appendix D). Use the AAR base address and size to
create an Address range for comparing the failing address.
For example, if AAR1 base address was 40000000 (1 GB) and its size was
10000000 (256 MB), the address range would be 40000000–4FFFFFFF
(4–4.25 GB). This range would be used to compare against the failing
address.
2. Determine if the Address XORing is enabled.
•
If Address XORING is enabled, use Table E–2 to find the real array on
which the failure occurred for 4-way interleaving, or Error! Reference
source not found. for 2-way interleaving.
•
If Bit 51 of the CSC register is set to 1, XORing is disabled.
Table E–2 Determining the Real Failed Array for 4-Way Interleaving
Failing
Address Original
<8:7> Array 0
00 Real Array 0
01 Real Array 1
10 Real Array 2
11 Real Array 3
Table E–3 Determining the Real Failed Array for 2-Way Interleaving
Failing
Address Original
<8> Array 0
0 Real Array 0
1 Real Array 2
Original Original
Array 1 Array 2
Real Array 1 Real Array 2
Real Array 0 Real Array 3
Real Array 3 Real Array 0
Real Array 2 Real Array 1
Original Original
Array 1 Array 2
Real Array 1 Real Array 2
Real Array 3 Real Array 0
Isolating Failing DIMMs
Original
Array 3
Real Array 3
Real Array 2
Real Array 1
Real Array 0
Original
Array 3
Real Array 3
Real Array 1
E-3