Service manual

3-6 AlphaServer DS20 Service Manual
Table 3-3 Dcache Status Register
Name Bits Type Description
Reserved <63:5> Reserved for Compaq.
SEO <4> W1C Second error occured. When set, indicates that a
second Dcache store ECC error occurred within 6
cycles of the previous Dcache store ECC error.
ECC_ERR
_LD
<3> W1C ECC error on load. When set, indicates that a
single-bit ECC error occurred while processing a
load from the Dcache or any fill.
ECC_ERR
_ST
<2> W1C ECC error on store. When set, indicates that an
ECC error occurred while processing a store.
TPERR_P1 <1> W1C Tag parity error — pipe 1. When set, indicates that
a Dcache tag probe from pipe 1 resulted in a tag
parity error. The error is uncorrectable and results
in a machine check.
TPERR_P0 <0> W1C Tag parity error — pipe 0. When set, this bit
indicates that a Dcache tag probe from pipe 1
resulted in a tag parity error. The error is
uncorrectable and results in a machine check.