Machine Status Save/Restore Register 1 (Srr1) - IBM PowerPC 750GX User Manual

4.3.2 Machine Status Save/Restore Register 1 (SRR1)

SRR1 is used to save machine status (selected MSR bits and possibly other status bits as well) on excep-
tions and to restore those values when a Return from Interrupt (rfi) instruction is executed.
When the 750GX takes a machine-check exception, it will set one or more error bits in SRR1, in Hardware-
Implementation-Dependent Register 2 (HID2), or in the L2 Cache Control Register (L2CR). A parity error in
either the internal L2 tag array or instruction-cache or data-cache tag arrays is indicated by the CP bit. A data-
parity error on the 60x bus is indicated by the DP bit. The MCpin bit indicates that the machine-check pin was
activated. The transfer error acknowledge (TEA) bit indicates the machine check was caused by a TEA
response on the 60x bus. An address-parity error on the 60x bus will set the AP bit.
Reserved CP Reserved
0 1 2 3 4 5 6
Bits
0:3
4
5:10
11
12
13
14
15
16:31
gx_04.fm.(1.2)
March 27, 2006
DP AP
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Field Name
Reserved
CP Set when an internal cache parity error is detected.
Reserved
L2DBERR Set when an L2 data-cache ECC double-bit error is detected.
MCpin Set when the machine-check pin is asserted.
TEA Set when a transfer error acknowledge (TEA) error is detected.
DP Set when a data-bus parity error is detected.
AP Set when an address-bus parity error is detected.
Reserved
IBM PowerPC 750GX and GL RISC Microprocessor
Reserved
Description
User's Manual
Exceptions
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