Multiply Single-Precision Value x Double-Precision Value (C67x+ CPU)

MPYSPDP

Pipeline

 

 

 

 

 

 

 

 

 

 

 

Pipeline

E1

E2

E3

E4

E5

E6

E7

 

 

 

 

Stage

 

 

 

 

 

 

 

 

 

 

 

 

 

Read

src1

src1

 

 

 

 

 

 

 

 

 

src2_l src2_h

 

 

 

 

 

 

 

 

Written

 

 

 

 

dst_l

dst_h

 

 

Unit in use

.M

.M

 

 

 

 

 

 

 

 

 

 

The low half of the result is written out one cycle earlier than the high half. If

 

dst is used as the source for the ADDDP, CMPEQDP, CMPLTDP, CMPGTDP,

 

MPYDP, MPYSPDP, MPYSP2DP, or SUBDP instruction, the number of delay

 

slots can be reduced by one, because these instructions read the lower word

 

of the DP source one cycle before the upper word of the DP source.

 

 

Instruction Type

MPYSPDP

 

 

 

 

 

 

 

 

Delay Slots

6

 

 

 

 

 

 

 

 

Functional Unit

3

 

 

 

 

 

 

 

 

Latency

 

 

 

 

 

 

 

 

 

 

See Also

MPY, MPYDP, MPYSP, MPYSP2DP

 

 

 

 

 

SPRU733

Instruction Set

3-169

Page 229
Image 229
Texas Instruments TMS320C67X/C67X+ DSP manual Mpyspdp, MPY, MPYDP, MPYSP, MPYSP2DP