INSTRUCTION DESCRIPTIONS
A - 82
INSTRUCTION SET DETAILS
MOTOROLA
Operation:
If
D[55]
⊕
S[23]=1,
Assembler Syntax:
DIV
S,D
Description:
Divide the destination operand D by the source operand S and store the result in the
destination accumulator D.
The 48-bit dividend must be a positive fraction which has
been sign extended to 56-bits and is stored in the full 56-bit destination accumula-
tor D. The 24-bit divisor is a signed fraction and is stored in the source operand S.
Each DIV iteration calculates one quotient bit using a nonrestoring fractional division
algorithm (see description on the next page). After the execution of the first DIV instruc-
tion, the destination operand holds both the partial remainder and the formed quotient.
The partial remainder occupies the high-order portion of the destination accumulator D
and is a signed fraction. The formed quotient occupies the low-order portion of the desti-
nation accumulator D (A0 or B0) and is a positive fraction. One bit of the formed quotient
is shifted into the LS bit of the destination accumulator at the start of each DIV iteration.
The formed quotient is the true quotient if the true quotient is positive. If the true quotient
is negative, the formed quotient must be negated.
Valid results are obtained only
when
|D| < |S|
and the operands are interpreted as fractions.
Note that this condition
ensures that the magnitude of the quotient is less than one (i.e., is fractional) and pre-
cludes division by zero.
DIV
Divide Interation
DIV
55
47
23
0
C+S
then
55
47
23
0
C–S
else
Destination Accumulator D
Destination Accumulator D
where
⊕
denotes the logical exclusive OR operator
D
D
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 ...