Compaq 21264 - Manual (Page 110)

4–22 Cache and External Interfaces Alpha 21264/EV67 Hardware Reference Manual
System Port
ReadBlkMod 10001 Memory read with modify intent.
ReadBlkI 10010 Memory read for Istream.
FetchBlk 10011 Noncached memory read.
ReadBlkSpec
2
10100 Speculative memory read (optional).
ReadBlkModSpec
2
10101 Speculative memory read with modify intent (optional).
ReadBlkSpecI
2
10110 Memory read for Istream (optional).
FetchBlkSpec
2
10111 Speculative memory noncached ReadBlk (optional).
ReadBlkVic
3
11000 Memory read with a victim (optional).
ReadBlkModVic
3
11001 Memory read with modify intent, with a victim (optional).
ReadBlkVicI
3
11010 Memory read for Istream with a victim (optional).
WrVictimBlk 00100 Write-back of dirty block.
CleanVictimBlk 00101 Address of a clean victim (optional).
Evict
4
00110 Invalidate evicted block at the given Bcache index (optional).
ReadBytes 01000 I/O read, byte mask.
ReadLWs 01001 I/O read, longword mask.
ReadQWs 01010 I/O read, quadword mask.
WrBytes 01100 I/O write, byte mask.
WrLWs 01101 I/O write, longword mask.
WrQWs 01110 I/O write, quadword mask.
CleanToDirty
6
11100 Sets a block dirty that was previously clean (optional for duplicate tags).
SharedToDirty
6
11101 Sets a block dirty that was previously shared (optional for multiprocessor
systems).
STCChangeToDirty
6
11110 Sets a block dirty that was previously clean or shared for a STx_C
instruction (optional for multiprocessor systems).
InvalToDirtyVic
3,5
11011 Invalid to dirty with a victim (optional).
InvalToDirty
5
11111 WH64 Acts like a ReadBlkMod without the fill cycles (optional).
Table 4–14 21264/EV67-to-System Commands Descriptions (Continued)
Command
Command
[4:0]
Function