User's Manual

15-32 Vol. 3
MACHINE-CHECK ARCHITECTURE
The behavior of error filtering after crossing the yellow threshold is model-
specific.
15.9.2.2 Transaction Type (TT) Sub-Field
The 2-bit TT sub-field (Table 15-10) indicates the type of transaction (data,
instruction, or generic). The sub-field applies to the TLB, cache, and inter-
connect error conditions. Note that interconnect error conditions are prima-
rily associated with P6 family and Pentium processors, which utilize an
external APIC bus separate from the system bus. The generic type is
reported when the processor cannot determine the transaction type.
15.9.2.3 Level (LL) Sub-Field
The 2-bit LL sub-field (see Table 15-11) indicates the level in the memory
hierarchy where the error occurred (level 0, level 1, level 2, or generic). The
LL sub-field also applies to the TLB, cache, and interconnect error condi
-
tions. The Pentium 4, Intel Xeon, and P6 family processors support two
levels in the cache hierarchy and one level in the TLBs. Again, the generic
type is reported when the processor cannot determine the hierarchy level.
15.9.2.4 Request (RRRR) Sub-Field
The 4-bit RRRR sub-field (see Table 15-12) indicates the type of action asso-
ciated with the error. Actions include read and write operations, prefetches,
cache evictions, and snoops. Generic error is returned when the type of error
cannot be determined. Generic read and generic write are returned when
the processor cannot determine the type of instruction or data request that
Table 15-10. Encoding for TT (Transaction Type) Sub-Field
Transaction Type Mnemonic Binary Encoding
Instruction I 00
Data D 01
Generic G 10
Table 15-11. Level Encoding for LL (Memory Hierarchy Level) Sub-Field
Hierarchy Level Mnemonic Binary Encoding
Level 0 L0 00
Level 1 L1 01
Level 2 L2 10
Generic LG 11