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12 mpyid instruction – Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 362

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Pipeline Execution of Instruction Types

Pipeline

4-30

SPRU733

4.2.12 MPYID Instruction

The MPYID instruction uses the E1 through E10 phases of the pipeline to
complete its operations (see Table 4−14). The sources are read on cycles E1
through 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 MPYID instruction is executed on
the .M unit. The functional unit latency for the MPYID instruction is 4.
Figure 4−24 shows the fetch, decode, and execute phases of the pipeline that
the MPYID instruction uses.

Table 4−14. MPYID Instruction Execution

Pipeline Stage

E1

E2

E3

E4

E5 E6 E7 E8

E9

E10

Read

src1
src2

src1
src2

src1
src2

src1
src2

Written

dst_l dst_h

Unit in use

.M

.M

.M

.M

Figure 4−24. MPYID Instruction Phases

PG

PS

PW

PR

DP

DC

E1

E2

E3

E4

E5

E6

E7

E8

E9 E10

9 delay slots