IBM PowerPC 750GX

User’s Manual
IBM PowerPC 750GX and GL RISC Microprocessor
gx_04.fm.(1.2)
March 27, 2006
Exceptions
Page 157 of 377
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
L2DBERR MCpin TEA
DP AP Reserved
012345678910111213141516171819202122232425262728293031
Bits Field Name Description
0:3 Reserved
4 CP Set when an internal cache parity error is detected.
5:10 Reserved
11 L2DBERR Set when an L2 data-cache ECC double-bit error is detected.
12 MCpin Set when the machine-check pin is asserted.
13 TEA Set when a transfer error acknowledge (TEA
) error is detected.
14 DP Set when a data-bus parity error is detected.
15 AP Set when an address-bus parity error is detected.
16:31 Reserved