Functional Unit Constraints
Pipeline4-36 SPRU733

Table 420 shows the instruction constraints for 2-cycle DP instructions exe-

cuting on the .S unit.

Table 420. 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