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2 .m-unit constraints – Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 372

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Functional Unit Constraints

Pipeline

4-40

SPRU733

4.3.2 .M-Unit Constraints

Table 4−24 shows the instruction constraints for 16 × 16 multiply instructions

executing on the .M unit.

Table 4−24. 16 y 16 Multiply .M-Unit Instruction Constraints

Instruction Execution

Cycle

1

2

3

16 × 16 multiply

R

W

Instruction Type

Subsequent Same-Unit Instruction Executable

16 × 16 multiply

n

n

4-cycle

n

n

MPYI

n

n

MPYID

n

n

MPYDP

n

n

Instruction Type

Same Side, Different Unit, Both Using Cross Path Executable

Single-cycle

n

n

Load

n

n

Store

n

n

DP compare

n

n

2-cycle DP

n

n

Branch

n

n

4-cycle

n

n

INTDP

n

n

ADDDP/SUBDP

n

n

Legend:

= E1 phase of the single-cycle instruction; R = Sources read for the instruction; W = Destinations written for the

instruction;

n

= Next instruction can enter E1 during cycle