INSTRUCTION DESCRIPTIONS
A - 154
INSTRUCTION SET DETAILS
MOTOROLA
Operation:
Assembler Syntax:
D
±
S1
∗
S2+r
➞
D (parallel move)
MACR
(
±
)S1,S2,D (parallel move)
D
±
S1
∗
S2+r
➞
D (parallel move)
MACR
(
±
)S2,S1,D (parallel move)
D
±
(S1
∗
2
-n
)+r
➞
D (no parallel move)
MACR
(
±
)S,#n,D (no parallel move)
Description: Multiply the two signed 24-bit source operands S1 and S2 (or the signed
24-bit source operand S by the positive 24-bit immediate operand 2
-n
), add/subtract the
product to/from the specified 56-bit destination accumulator D, and then round the result
using convergent rounding. The rounded result is stored in the destination accumulator
D.
The “–” sign option negates the specified product prior to accumulation. The default sign
option is “+”.
The contribution of the LS bits of the result is rounded into the upper portion of the desti-
nation accumulator (A1 or B1) by adding a constant to the LS bits of the lower portion of
the accumulator (A0 or B0). The value of the constant added is determined by the scal-
ing mode bits S0 and S1 in the status register. Once rounding has been completed, the
LS bits of the destination accumulator D (A0 or B0) are loaded with zeros to maintain an
unbiased accumulator value which may be reused by the next instruction. The upper por-
tion of the accumulator (A1 or B1) contains the rounded result which may be read out to
the data buses. Refer to the RND instruction for more complete information on the con-
vergent rounding process.
Example 1:
:
MACR X0,Y0,B
B,X0 Y:(R4)+N4,Y0
;X0
∗
Y0+B
➞
B, and B, update X0,Y0,R4
:
MACR
Signed Multiply-Accumulate and Round
MACR
Before Execution
After Execution
X0
X0
Y0
Y0
B
B
$00:100000:000000
$00:1296CE:000000
$987654
$100000
$123456
$123456
Summary of Contents for DSP56K
Page 12: ...xii LIST of TABLES MOTOROLA List of Tables Continued Table Page Number Title Number ...
Page 13: ...MOTOROLA DSP56K FAMILY INTRODUCTION 1 1 SECTION 1 DSP56K FAMILY INTRODUCTION ...
Page 31: ...MOTOROLA DATA ARITHMETIC LOGIC UNIT 3 1 SECTION 3 DATA ARITHMETIC LOGIC UNIT ...
Page 50: ...DATA ALU SUMMARY 3 20 DATA ARITHMETIC LOGIC UNIT MOTOROLA ...
Page 51: ...MOTOROLA ADDRESS GENERATION UNIT 4 1 SECTION 4 ADDRESS GENERATION UNIT ...
Page 77: ...MOTOROLA PROGRAM CONTROL UNIT 5 1 SECTION 5 PROGRAM CONTROL UNIT ...
Page 124: ...INSTRUCTION GROUPS 6 30 INSTRUCTION SET INTRODUCTION MOTOROLA ...
Page 125: ...MOTOROLA PROCESSING STATES 7 1 SECTION 7 PROCESSING STATES STOP WAIT EXCEPTION NORMAL RESET ...
Page 167: ...STOP PROCESSING STATE MOTOROLA PROCESSING STATES 7 43 ...
Page 168: ...STOP PROCESSING STATE 7 44 PROCESSING STATES MOTOROLA ...
Page 169: ...MOTOROLA PORT A 8 1 SECTION 8 PORT A ...
Page 176: ...PORT A INTERFACE 8 8 PORT A MOTOROLA ...
Page 177: ...MOTOROLA PLL CLOCK OSCILLATOR 9 1 SECTION 9 PLL CLOCK OSCILLATOR x x d Φ VCO ...
Page 191: ...10 2 ON CHIP EMULATION OnCE MOTOROLA SECTION 10 ON CHIP EMULATION OnCE ...
Page 218: ...USING THE OnCE MOTOROLA ON CHIP EMULATION OnCE 10 29 ...
Page 604: ...INSTRUCTION ENCODING A 338 INSTRUCTION SET DETAILS MOTOROLA ...
Page 605: ...MOTOROLA BENCHMARK PROGRAMS B 1 APPENDIX B BENCHMARK PROGRAMS T T T T T P1 P3 P2 P4 T T T ...
Page 609: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 5 ...
Page 611: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 7 ...
Page 613: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 9 ...
Page 615: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 11 ...