Functional Unit Constraints
4-51PipelineSPRU733

Table 435 shows the instruction constraints for ADDDP/SUBDP instructions

executing on the .L unit.

Table 435. ADDDP/SUBDP .L-Unit Instruction Constraints
Instruction Execution
Cycle 1 2 3 4 5 6 7 8
ADDDP/SUBDP R R W W
Instruction Type Subsequent Same-Unit Instruction Executable
Single-cycle Xr   Xw Xw
4-cycle Xr Xw Xw 
INTDP Xrw Xw Xw 
ADDDP/SUBDP Xr 
Instruction Type Same Side, Different Unit, Both Using Cross Path Executable
Single-cycle Xr      
DP compare Xr 
2-cycle DP Xr 
4-cycle Xr 
Load 
Store 
Branch Xr 
16 ×16 multiply Xr 
MPYI Xr 
MPYID Xr 
MPYDP 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 cyclewrite constraint; Xrw = Next instruction cannot
enter E1 during cycleread/decode/write constraint