Functional Unit Hazards
6-38
6.3.5
Single-Cycle Instructions
Single-cycle instructions complete execution during the E1 phase of the pipe-
line (see Table 6–20). Figure 6–8 shows the fetch, decode, and execute
phases of the pipeline that single-cycle instructions use. Figure 6–9 is the
single-cycle execution diagram. The operands are read, the operation is per-
formed, and the results are written to a register, all during E1. Single-cycle
instructions have no delay slots.
Table 6–20. Single-Cycle Execution
Pipeline
Stage
E1
Read
src1
src2
Written
dst
Unit in use
.L, .S., .M, or
.D
Figure 6–8. Single-Cycle Instruction Phases
PG
PS
PW
PR
DP
DC
E1
Figure 6–9. Single-Cycle Execution Block Diagram
(data)
Operands
ÁÁÁÁÁÁ
ÁÁÁÁÁÁ
ÁÁÁÁÁÁ
Register file
Write results
ÁÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁ
Functional
unit
.L, .S, .M,
or .D
E1