Texas Instruments TMS320C67X/C67X+ DSP Car Speaker User Manual


 
Pipeline Execution of Instruction Types
4-25PipelineSPRU733
4.2.7 Four-Cycle Instructions
Four-cycle instructions use the E1 through E4 phases of the pipeline to
complete their operations (see Table 49). The following instructions are
four-cycle instructions:
ADDSP
DPINT
DPSP
DPTRUNC
INTSP
MPYSP
SPINT
SPTRUNC
SUBSP
The sources are read on E1 and the results are written on E4. The four-cycle
instructions are executed on the .M or .L units. The status is written to the
FMCR or FADCR on E4. Figure 419 shows the fetch, decode, and execute
phases of the pipeline that the four-cycle instructions use.
Table 49. Four-Cycle Instruction Execution
Pipeline Stage
E1 E2 E3 E4
Read src1
src2
Written dst
Unit in use
.L or .M
Figure 419. Four-Cycle Instruction Phases
PG PS PW PR DP DC E1 E2 E3 E4
3 delay slots