Functional Unit Hazards
6-49
TMS320C67x Pipeline
6.3.14 ADDDP/SUBDP Instructions
The ADDDP/SUBDP instructions use the E1 through E7 phases of the pipeline
to complete their operations (see Table 6–29). The lower 32 bits of the result
are written on E6, and the upper 32 bits of the result are written on E7. The
ADDDP/SUBDP instructions are executed on the .L unit. The functional unit
latency for ADDDP/SUBDP instructions is 2. The status is written to the
FADCR on E6. Figure 6–22 shows the pipeline phases the ADDDP/SUBDP
instructions use.
Table 6–29. ADDDP/SUBDP Execution
Pipeline
Stage
E1
E2
E3
E4
E5
E6
E7
Read
src1_l
src2_l
src1_h
src2_h
Written
dst_l
dst_h
Unit in use
.L
.L
Figure 6–22. ADDDP/SUBDP Instruction Phases
PG
PS
PW
PR
DP
DC
E1
E2
E3
E4
E5
E6
E7
6 delay slots