Chapter 12
366 MIPS R4000 Microprocessor User's Manual
Read Requests
Figure 12-43 shows the format of a SysCmd read request.
Figure 12-43 Read Request SysCmd Bus Bit Definition
Tables 12-12 through 12-14 list the encodings of SysCmd(4:0) for read
requests.
Table 12-12 Encoding of SysCmd(4:3) for Read Requests
Table 12-13 Encoding of SysCmd(2:0) for Coherent and Noncoherent
Block Read Request
SysCmd(4:3) Read Attributes
0 Coherent block read
1 Coherent block read, exclusivity requested
2 Noncoherent block read
3 Doubleword, partial doubleword, word, or partial word
SysCmd(2) Link Address Retained Indication
0 Link address not retained
1 Link address retained
SysCmd(1:0) Read Block Size
0 4 words
1 8 words
2 16 words
3 32 words
000
or
001
0
8 7 5 4 03 2 1
Read Request Specific
(see tables)
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