Functional Unit Constraints
4-51
Pipeline
SPRU733
Table 4
−
35 shows the instruction constraints for
ADDDP/SUBDP
instructions
executing on the .L unit.
Table 4
−
35. 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 cycle
−
write constraint; Xrw = Next instruction cannot
enter E1 during cycle
−
read/decode/write constraint