Mips Technologies R4000 - Write Requests

MIPS R4000 Microprocessor User's Manual 367
System Interface
Table 12-14 Doubleword, Word, or Partial-word Read Request Data Size
Encoding of SysCmd(2:0)
Write Requests
Figure 12-44 shows the format of a SysCmd write request.
Table 12-15 lists the write attributes encoded in bits SysCmd(4:3). Table
12-16 lists the block write replacement attributes encoded in bits
SysCmd(2:0). Table 12-17 lists the write request bit encodings in
SysCmd(2:0).
Figure 12-44 Write Request SysCmd Bus Bit Definition
Table 12-15 Write Request Encoding of SysCmd(4:3)
SysCmd(2:0) Read Data Size
0 1 byte valid (Byte)
1 2 bytes valid (Halfword)
2 3 bytes valid (Tribyte)
3 4 bytes valid (Word)
4 5 bytes valid (Quintibyte)
5 6 bytes valid (Sextibyte)
6 7 bytes valid (Septibyte)
7 8 bytes valid (Doubleword)
SysCmd(4:3) Write Attributes
0 Reserved
1 Reserved
2 Block write
3
Doubleword, partial doubleword, word, or
partial word
010
0
8 7 5 4 03 2 1
Write Request Specific
(see tables)