Pipeline Operation Overview

Many C67x DSP instructions are single-cycle instructions, which means they have only one execution phase (E1). The other instructions require more than one execute phase. The types of instructions, each of which require different numbers of execute phases, are described in section 4.2.

Example 4−1. Execute Packet in Figure 4−7

 

LDDW

.D1

*A0−−[4],B5:B4

; E1 Phase

ADDSP

.L1

A9,A10,A12

 

SUBSP

.L2X

B12,A2,B12

 

MPYSP

.M1X

A6,B13,A11

 

MPYSP

.M2

B5,B13,B11

 

ABSSP

.S1

A12,A15

 

 

LDDW

.D1

*A0++[5],A7:A6

; DC Phase

ADDSP

.L1

A12,A11,A12

 

ADDSP

.L2

B10,B11,B12

 

MPYSP

.M1X

A4,B6,A9

 

MPYSP

.M2X

A7,B6,B9

 

CMPLTSP

.S1

A15,A8,A1

 

ABSSP

.S2

B12,B15

 

LOOP:

 

 

 

 

[!B2]

LDDW

.D1

*A0++[2],A5:A4

; DP and PS Phases

[B2]

ZERO

.D2

B0

 

SUBSP

.L1

A12,A2,A12

 

ADDSP

.L2

B9,B12,B12

 

MPYSP

.M1X

A5,B7,A10

 

MPYSP

.M2

B4,B7,B10

 

[B0]

B

.S1

LOOP

 

[!B1]

CMPLTSP

.S2

B15,B8,B1

 

[!B2]

LDDW

.D1

*A0−−[4],B5:B4

; PR and PG Phases

[B0]

SUB

.D2

B0,2,B0

 

ADDSP

.L1

A9,A10,A12

 

SUBSP

.L2X

B12,A2,B12

 

MPYSP

.M1X

A6,B13,A11

 

MPYSP

.M2

B5,B13,B11

 

ABSSP

.S1

A12,A15

 

[A1]

MVK

.S2

1,B2

 

[!B2]

LDDW

.D1

*A0++[5],A7:A6

; PW Phase

[B1]

MV

.D2

B1,B2

 

ADDSP

.L1

A12,A11,A12

 

ADDSP

.L2

B10,B11,B12

 

MPYSP

.M1X

A4,B6,A9

 

[!A1]

CMPLTSP

.S1

A15,A8,A1

 

ABSSP

.S2

B12,B15

 

 

 

 

 

 

SPRU733

Pipeline

4-11

Page 343
Image 343
Texas Instruments TMS320C67X/C67X+ DSP manual Example 4−1. Execute Packet in −7