
8-7
DATA INTEGRITY
•
Arbitration time-out. If BPRI# is asserted for more than a reasonable number of clocks,
then the central agent should indicate a bus protocol violation.
8.2.5.
Hard-error Response
The target can assert a hard-error response in the Response Phase to a transaction that has gen-
erated an error. The central agent can also claim responsibility for a transaction after response
time-out expiration and terminate the transaction with a hard error response.
On observing a hard-error response, the initiator may treat it as a unrecoverable or a fatal error.
8.2.6.
Bus Error Codes
8.2.6.1.
PARITY ALGORITHM
All bus parity signals use the same algorithm to compute correct parity. A correct parity signal
is high if all covered signals are high, or if an even number of covered signals are low. A correct
parity signal is low if an odd number of covered signals are low. Parity is computed using voltage
levels, regardless of whether the covered signals are active-high or active-low. Depending on the
number of covered signals, a parity signal can be viewed as providing “even” or “odd” parity;
this specification does not use either term.
8.2.6.2.
PENTIUM
®
PRO PROCESSOR BUS ECC ALGORITHM
The Pentium Pro processor bus uses an ECC code that can correct single-bit errors, detect dou-
ble-bit errors, and detect all errors confined to one nibble (SEC-DED-S4ED). System designers
may choose to detect all these errors, or a subset of these errors. They may also choose to use
the same ECC code in L3 caches, main memory arrays, or I/O subsystem buffers.
8.3.
ERROR REPORTING MECHANISM
8.3.1.
MCA Hardware Log
If CR4.MCE is set, all errors are logged using the available MCA hardware.
8.3.2.
MCA Software Log
If CR4.MCE is set, unrecoverable errors cause entry into the INT 18 exception handler, as in the
Pentium processor. The INT 18 exception handler will not be entered if the error occurs while a
machine check is in progress (MCIP). The exception handler will also not be entered by a check-
er of a FRC pair. The exception handler can be used to determine the exact source of the error
by reading the model specific registers associated with the unit reporting the error. Internal ma-
chine check errors are aborts, as in the Pentium processor, but may be restartable in some cases.
Содержание Pentium Pro Family
Страница 17: ...1 Component Introduction ...
Страница 26: ...2 Pentium Pro Processor Architecture Overview ...
Страница 27: ......
Страница 36: ...3 Bus Overview ...
Страница 62: ...4 Bus Protocol ...
Страница 105: ...5 Bus Transactions and Operations ...
Страница 126: ...6 Range Registers ...
Страница 131: ...7 Cache Protocol ...
Страница 135: ...8 Data Integrity ...
Страница 148: ...9 Configuration ...
Страница 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Страница 172: ...11 Electrical Specifications ...
Страница 201: ...12 GTL Interface Specification ...
Страница 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Страница 233: ...14 Thermal Specifications ...
Страница 239: ...15 Mechanical Specifications ...
Страница 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Страница 252: ...16 Tools ...
Страница 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Страница 264: ...17 OverDrive Processor Socket Specification ...
Страница 290: ...A Signals Reference ...
Страница 320: ...Index ...
Страница 328: ......