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Pipeline Execution of Instruction Types
4.2.14 MPYSPDP Instruction
The MPYSPDP instruction uses the E1 through E7 phases of the pipeline to
complete its operations (see Table 4−16). src1 is read on E1 and E2. The lower
32 bits of src2 are read on E1, and the upper 32 bits of src2 are read on E2.
The lower 32 bits of the result are written on E6, and the upper 32 bits of the
result are written on E7. The MPYSPDP instruction is executed on the .M unit.
The functional unit latency for the MPYSPDP instruction is 3. Figure 4−26
shows the fetch, decode, and execute phases of the pipeline that the
MPYSPDP instruction uses.
Table 4−16. MPYSPDP Instruction Execution
E1 E2 E3 E4 E5 E6 E7
Written dst_l dst_h
Unit in use
Figure 4−26. MPYSPDP Instruction Phases
PG PS PW PR DP DC E1 E2 E3 E4 E5 E6 E7
6 delay slots