Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 346

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Pipeline Execution of Instruction Types

Pipeline

4-14

SPRU733

Table 4−2. Execution Stage Length Description for Each Instruction Type (Continued)

Instruction Type

Execution
phases

ADDDP/SUBDP

MPYI

MPYID

MPYDP

E1

Read lower sources
and start computation

Read sources and
start computation

Read sources and
start computation

Read lower sources
and start computation

E2

Read upper sources
and continue
computation

Read sources and
continue computation

Read sources and
continue computation

Read lower src1 and
upper src2 and
continue computation

E3

Continue computation Read sources and

continue computation

Read sources and
continue computation

Read lower src2 and
upper src1 and
continue computation

E4

Continue computation Read sources and

continue computation

Read sources and
continue computation

Read upper sources
and continue
computation

E5

Continue computation Continue computation Continue computation Continue computation

E6

Compute the lower
results and write to
register

Continue computation Continue computation Continue computation

E7

Compute the upper
results and write to
register

Continue computation Continue computation Continue computation

E8

Continue computation Continue computation Continue computation

E9

Complete computa-
tion and write results
to register

Continue computation
and write lower
results to register

Continue computation
and write lower
results to register

E10

Complete computa-
tion and write upper
results to register

Complete computa-
tion and write upper
results to register

Delay slots

6

8

9

9

Functional
unit latency

2

4

4

4

Notes:

1) This table assumes that the condition for each instruction is evaluated as true. If the condition is evaluated as

false, the instruction does not write any results or have any pipeline operation after E1.

2) NOP is not shown and has no operation in any of the execution phases.

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