Functional Unit Constraints
Pipeline
4-46
SPRU733
Table 4
−
30 shows the instruction constraints for
MPYSPDP
instructions
executing on the .M unit.
Table 4
−
30. MPYSPDP .M-Unit Instruction Constraints
Instruction Execution
Cycle
1
2
3
4
5
6
7
MPYSPDP
R
R
W
W
Instruction Type
Subsequent Same-Unit Instruction Executable
16
×
16 multiply
Xr
Xw
Xw
MPYDP
Xr
Xu
Xu
MPYI
Xr
Xu
Xu
MPYID
Xr
Xu
Xu
MPYSP
Xr
Xw
Xw
MPYSPDP
Xr
Xu
MPYSP2DP
Xr
Xw
Xw
Instruction Type
Same Side, Different Unit, Both Using Cross Path Executable
Single-cycle
Xr
Load
Xr
Store
Xr
DP compare
Xr
2-cycle DP
Xr
Branch
Xr
4-cycle
Xr
INTDP
Xr
ADDDP/SUBDP
Xr
Legend:
= E1 phase of the single-cycle instruction; R = Sources read for the instruction; W = Destinations written for the
instruction;
= Next instruction can enter E1 during cycle; Xr = Next instruction cannot enter E1 during cycle
−
read/
decode constraint; Xw = Next instruction cannot enter E1 during cycle
−
write constraint; Xu = Next instruction cannot
enter E1 during cycle
−
other resource conflict