Functional Unit Constraints
4-35PipelineSPRU733

Table 419 shows the instruction constraints for DP compare instructions

executing on the .S unit.
Table 419. DP Compare .S-Unit Instruction Constraints
Instruction Execution
Cycle 1 2 3
DP compare R RW
Instruction Type Subsequent Same-Unit Instruction Executable
Single-cycle Xrw
DP compare Xr
2-cycle DP Xrw
ADDDP/SUBDP Xr
ADDSP/SUBSP Xr
BranchXr
Instruction Type Same Side, Different Unit, Both Using Cross Path Executable
Single-cycle Xr
Load Xr
Store Xr
INTDP Xr
ADDDP/SUBDP Xr
16 ×16 multiply Xr
4-cycle 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; Xrw = Next instruction cannot enter E1 during cycle-read/decode/write constraint
The branch on register instruction is the only branch instruction that reads a general-purpose register