Texas Instruments TMS320C67X/C67X+ DSP - Manual (Page 363)

Pipeline Execution of Instruction Types
4-31 Pipeline SPRU733
4.2.13 MPYDP Instruction
The MPYDP instruction uses the E1 through E10 phases of the pipeline to
complete its operations (see Table 4−15). The lower 32 bits of src1 are read
on E1 and E2, and the upper 32 bits of src1 are read on E3 and E4. The lower
32 bits of src2 are read on E1 and E3, and the upper 32 bits of src2 are read
on E2 and E4. The lower 32 bits of the result are written on E9, and the upper
32 bits of the result are written on E10. The MPYDP instruction is executed on
the .M unit. The functional unit latency for the MPYDP instruction is 4. The
status is written to the FMCR on E9. Figure 4−25 shows the fetch, decode, and
execute phases of the pipeline that the MPYDP instruction uses.
Table 4−15. MPYDP Instruction Execution
Pipeline
Stage
E1 E2 E3 E4 E5 E6 E7 E8 E9 E10
Read src1_l
src2_l src1_l
src2_h
src1_h
src2_l
src1_h
src2_h
Written dst_l dst_h
Unit in use .M .M .M .M
Figure 4−25. MPYDP Instruction Phases
PG PS PW PR DP DC E1 E2 E3 E4 E5 E6 E7 E8 E9 E10
9 delay slots