Functional Unit Constraints
Pipeline4-42 SPRU733
Table 4−26 shows the instruction constraints for MPYI instructions executing
on the .M unit.
Table 4−26. MPYI .M-Unit Instruction Constraints
Instruction Execution
Cycle 1 2 3 4 5 6 7 8 9 10
MPYI R R R R W
Instruction Type
Subsequent Same-Unit Instruction Executable
16 × 16 multiply Xr Xr Xr Xw
4-cycle Xr Xr Xr Xu Xw Xu
MPYI
Xr Xr Xr
MPYID
Xr Xr Xr
MPYDP
Xr Xr Xr Xu Xu Xu
MPYSPDP
Xr Xr Xr Xu Xu Xu
MPYSP2DP
Xr Xr Xr Xw Xw Xu
Instruction Type
Same Side, Different Unit, Both Using Cross Path Executable
Single-cycle Xr Xr Xr
Load
Store
DP compare
Xr Xr Xr
2-cycle DP
Xr Xr Xr
Branch
Xr Xr Xr
4-cycle
Xr Xr Xr
INTDP
Xr Xr Xr
ADDDP/SUBDP
Xr Xr 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