Pipeline Execution of Instruction Types

4.2.11 MPYI Instruction

The MPYI instruction uses the E1 through E9 phases of the pipeline to complete its operations (see Table 4−13). The sources are read on cycles E1 through E4 and the result is written on E9. The MPYI instruction is executed on the .M unit. The functional unit latency for the MPYI instruction is 4. Figure 4−23 shows the fetch, decode, and execute phases of the pipeline that the MPYI instruction uses.

Table 4−13. MPYI Instruction Execution

Pipeline Stage

E1

E2

E3

E4

E5

E6

E7

E8

E9

 

 

 

 

 

 

 

 

 

 

Read

src1

src1

src1

src1

 

 

 

 

 

 

src2

src2

src2

src2

 

 

 

 

 

Written

 

 

 

 

 

 

 

 

dst

Unit in use

.M

.M

.M

.M

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 4−23. MPYI Instruction Phases

PG PS PW PR DP DC E1

E2

E3

E4

E5

E6

E7

E8

E9

8 delay slots

SPRU733

Pipeline

4-29

Page 361
Image 361
Texas Instruments TMS320C67X/C67X+ DSP manual 13. Mpyi Instruction Execution