INSTRUCTION FORMATS
6 - 6
INSTRUCTION SET INTRODUCTION
MOTOROLA
6.3.2 Data Organization in Registers
The ten data ALU registers support 8- or 24-bit data operands. Instructions also support
48- or 56-bit data operands by concatenating groups of specific data ALU registers. The
eight address registers in the AGU support 16-bit address or data operands. The eight
AGU offset registers support 16-bit offsets or may support 16-bit address or data oper-
ands. The eight AGU modifier registers support 16-bit modifiers or may support 16-bit
address or data operands. The program counter (PC) supports 16-bit address operands.
The status register (SR) and operating mode register (OMR) support 8- or 16-bit data
operands. Both the loop counter (LC) and loop address (LA) registers support 16-bit
address operands.
6.3.2.1
Data ALU Registers
The eight main data ALU registers are 24 bits wide. Word operands occupy one register;
long-word operands occupy two concatenated registers. The least significant bit (LSB) is
the right-most bit (bit 0) and the most significant bit (MSB) is the left-most bit (bit 23 for
word operands and bit 47 for long-word operands). The two accumulator extension regis-
ters are eight bits wide.
When an accumulator extension register acts as a source operand, it occupies the low-
order portion (bits 0–7) of the word and the high-order portion (bits 8–23) is sign extended
(see Figure 6-4). When used as a destination operand, this register receives the low-order
portion of the word, and the high-order portion is not used. Accumulator operands occupy
an entire group of three registers (i.e., A2:A1:A0 or B2:B1:B0). The LSB is the right-most
bit (bit 0), and the MSB is the left-most bit (bit 55).
Figure 6-3 Operand Sizes
55
0
47
0
23
0
7
0
15
0
ACCUMULATOR
LONG WORD
WORD
SHORT WORD
BYTE
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 ...