Error Case Summary

Table 8–3 Error Case Summary (Continued)

 

 

 

Hardware

 

Error

Exception

Status

Action

PALcode Action

 

 

 

 

 

Memory single-bit

MCHK

C_STAT[ISTREAM_MEM_ERR]

Icache flushed

Scrub error as described

error on Icache fill

and CRD2

C_ADDR[error address]

 

in Section D.36.

 

 

C_SYNDROME_0

 

Log as CRD

 

 

C_SYNDROME_1

 

 

Memory single-bit

CRD

DC_STAT[ECC_ERR_LD]

Corrected and

Scrub error as described

error on Dcache fill

 

C_STAT[DSTREAM_MEM_ERR]

scrubbed in

in Section D.36.

 

 

C_ADDR[error address]

Dcache3

Log as CRD

 

 

C_SYNDROME_0

 

 

 

 

C_SYNDROME_1

 

 

Bcache single-bit

CRD

C_STAT[PROBE_BC_ERR]

None

May scrub error as

error on a probe hit

 

C_ADDR[error address]4

 

described in Section

 

 

C_SYNDROME_0

 

D.36.

 

 

C_SYNDROME_1

 

Log as CRD

Bcache double-bit

MCHK1

C_STAT[ISTREAM_BC_DBL]

None

Log as MCHK

error on Icache fill

 

C_ADDR[error address]4

 

 

Bcache double-bit

MCHK1

C_STAT[DSTREAM_BC_DBL]

None

Log as MCHK

error on Dcache fill

 

C_ADDR[error address]4

 

 

Memory double-bit

MCHK1

C_STAT[ISTREAM_MEM_DBL]

None

Log as MCHK

error on Icache fill

 

C_ADDR[error address]4

 

 

Memory double-bit

MCHK1

C_STAT[DSTREAM_MEM_DBL]

None

Log as MCHK

error on Dcache fill

 

C_ADDR[error address]4

 

 

1Machine check taken in native mode. It is deferred while in PALmode.

2CRD error posted in case the machine check is down a speculative path.

3For a single-bit error on a non-target quadword, the error is not corrected in hardware, but is corrected by PALcode during the scrub operation.

4The contents of C_ADDR may not be accurate when there is heavy cache fill traffic.

21264/EV68A Hardware Reference Manual

Error Detection and Error Handling 8–11

Page 239
Image 239
Compaq EV68A specifications Mchk Cstatistreammemerr, Cstatdstreammemerr, CRD Cstatprobebcerr, Mchk Cstatistreambcdbl