Functional Unit Constraints
Pipeline4-36 SPRU733
Table 4−20 shows the instruction constraints for 2-cycle DP instructions exe-
cuting on the .S unit.
Table 4−20. 2-Cycle DP .S-Unit Instruction Constraints
Instruction Execution
Cycle 1 2 3
2-cycle RW W
Instruction Type
Subsequent Same-Unit Instruction Executable
Single-cycle Xw
DP compare
2-cycle DP
Xw
ADDDP/SUBDP
ADDSP/SUBSP
Branch
Instruction Type
Same Side, Different Unit, Both Using Cross Path Executable
Single cycle
Load
Store
INTDP
ADDDP/SUBDP
16 × 16 multiply
4-cycle
MPYI
MPYID
MPYDP
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; Xw = Next instruction cannot enter E1 during cycle-write
constraint
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