MIPS R10000 Microprocessor User's Manual - SGI TechPubs Library

88 Chapter 6.
Request and Response Relationship
‡ External completion response is required to free the request number.
The relationship between processor and external requests, and their acceptable
responses, is presented in Table 6-1. The data in this table is given with respect to
a single processor, in either a uni- or multiprocessor system (independent of
cluster/non-cluster configuration).
Table 6-1 Request and Response Relationship
Request Acceptable Response Sequences
Processor block read request
External NACK or ERR completion response
0 or more external block data responses followed by a final external block
data response with a coincidental or subsequent external ACK, NACK, or
ERR completion response
External NACK or ERR completion response
Processor double/single/partial- 0 or more external double/single/partial-word data responses followed
word read request
by a final external double/single/partial-word data response with a
coincidental or subsequent external ACK, NACK, or ERR completion
response
Processor block write request None
Processor double/single/partial-
None
word write request
External ACK, NACK, or ERR completion response
Processor upgrade request
0 or more external block data responses followed by a final external block
data response with a coincidental or subsequent external ACK, NACK, or
ERR completion response
Processor eliminate request None
External intervention request
External allocate request number
request
Processor coherency state response followed by processor coherency data
response (if DirtyExclusive) with a coincidental or subsequent external
ACK, NACK, or ERR completion response ‡
External ACK, NACK, or ERR completion response *
External invalidate request
Processor coherency state response followed by external ACK, NACK, or
ERR completion response *
External interrupt request None
Version 2.0 of January 29, 1997 MIPS R10000 Microprocessor User's Manual