3-2
AlphaServer DS20 Service Manual
3.1
Ibox Status Register - I_STAT
The Ibox Status Register (I_STAT) is a read/write-1-to-clear register that
contains Ibox status information. The register is read only by PAL code and is
an element in the CPU or System Uncorrectable Machine Check Error Logout
frame.
61
0
32
PK1414-99
30
31
29 28
TPE
DPE
Table 3-1 Ibox Status Register
Name
Bits
Type
Description
Reserved
<63:31>
RO
Reserved for Compaq.
DPE
<30>
W1C
Icache data parity error
When set, indicates that the Icache
encountered a data parity error on instruction
fetch.
TPE
<29>
W1C
Icache tag parity error
When set, indicates that the Icache
encountered a tag parity error on instruction
fetch.
Reserved
<28:0>
RO
Reserved for Compaq.