AGU ARCHITECTURE
MOTOROLA
ADDRESS GENERATION UNIT
4 - 5
GDB. When read by the GDB, the contents of a register are placed in the two least signif-
icant bytes, and the most significant byte on the GDB is zero extended. When a register
is written, only the least significant 16 bits of the GDB are used; the upper portion is
truncated.
4.2.3 Modifier Register Files (Mn)
Each of the two modifier register files shown in Figure 4-2 consists of four 16-bit registers.
The two files contain modifier registers M0 - M3 and M4 - M7, which specify the type of
arithmetic used during address register update calculations or contain data. Each modifier
register can be read or written by the GDB. When read by the GDB, the contents of a reg-
ister are placed in the two least significant bytes, and the most significant byte on the GDB
is zero extended. When a register is written, only the least significant 16 bits of the GDB
are used; the upper portion is truncated. Each modifier register is preset to $FFFF during
a processor reset.
4.2.4 Address ALU
The two address ALUs are identical (see Figure 4-2) in that each contains a 16-bit full
adder (called an offset adder), which can add 1) plus one, 2) minus one, 3) the contents
of the respective offset register N, or 4) the twos complement of N to the contents of the
GLOBAL DATA BUS
N0
N1
N2
N3
M3
M2
M1
M0
ADDRESS
ALU
ADDRESS
ALU
R0
R1
R2
R3
R7
R6
R5
R4
M4
M5
M6
M7
N7
N6
N5
N4
TRIPLE MULTIPLEXER
LOW ADDRESS ALU
HIGH ADDRESS ALU
XAB
YAB
PAB
16 bits
24 bits
Figure 4-2 AGU Block Diagram
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 ...