Sable CPU Module Specification

Copyright © 1993 Digital Equipment Corporation.
3.9.10 Fill Syndrome Register (FILL_SYNDROME)
The FILL_SYNDROME register is a 14-bit read-only register.
If the chip is in EDC mode and an EDC error is recognized during a primary cache
fill operation, the syndrome bits associated with the bad quadword are locked in
the FILL_SYNDROME register. FILL_SYNDROME[6..0] contain the syndrome associated
with the lower longword of the quadword, and FILL_SYNDROME[13..7]
contain the syndrome associated with the upper longword of the quadword. A syndrome
value of zero means that no errors where found in the associated longword.
See Table 25 for a list of syndromes associated with correctable single-bit errors. The
FILL_SYNDROME register is unlocked when the FILL_ADDR register is read.
If the chip is in parity mode and a parity error is recognized during a primary cache
fill operation, the FILL_SYNDROME register indicates which of the longword in the
quadword got bad parity. FILL_SYNDROME[0] is set to indicate that the low longword
was corrupted, and FILL_SYNDROME[7] is set to indicate that the high longword
was corrupted. FILL_SYNDROME[13..8] and [6..1] are RAZ in parity mode.
Figure 38: Fill Syndrome
Table 25: Syndromes for Single-Bit Errors
6
3
1 1
4 3
0 0
7 6
RAZ HI[6..0] LO[6..0]
0
0
FILL_SYNDROME
Data Bit Syndrome(Hex) Check Bit Syndrome(Hex)
00 4F 00 01
01 4A 01 02
02 52 02 04
03 54 03 08
04 57 04 10
05 58 05 20
06 5B 06 40
07 5D
08 23
09 25
10 26
11 29
78 Functions Located on the DECchip 21064