DSP56309 Overview
DSP56300 Core Functional Blocks
MOTOROLA
DSP56309UM/D 1-9
All the Data ALU operations are performed in two clock cycles in pipeline fashion so
that a new instruction can be initiated in every clock, yielding an effective execution rate
of one instruction per clock cycle. The destination of every arithmetic operation can be
used as a source operand for the immediately following operation without penalty.
1.6.1.2
Multiplier-Accumulator (MAC)
The MAC unit comprises the main arithmetic processing unit of the DSP56300 core and
performs all of the calculations on data operands. For arithmetic instructions, the unit
accepts as many as three input operands and outputs one 56-bit result of the following
form, Extension:Most Significant Product:Least Significant Product (EXT:MSP:LSP).
The multiplier executes 24-bit
´
24-bit, parallel, fractional multiplies between
twos-complement signed, unsigned, or mixed operands. The 48-bit product is
right-justified and added to the 56-bit contents of either the A or B accumulator. A 56-bit
result can be stored as a 24-bit operand. The LSP can either be truncated or rounded into
the MSP. Rounding is performed if specified.
1.6.2
Address Generation Unit (AGU)
The AGU performs the effective address calculations using integer arithmetic necessary
to address data operands in memory and contains the registers that generate the
addresses. It implements four types of arithmetic: linear, modulo, multiple wrap-around
modulo, and reverse-carry. The AGU operates in parallel with other chip resources to
minimize address-generation overhead.
The AGU is divided into two halves, each with its own address arithmetic logic unit
(Address ALU). Each Address ALU has four sets of register triplets, and each register
triplet is composed of an address register, an offset register, and a modifier register. The
two Address ALUs are identical. Each contains a 16-bit full adder (called an offset
adder).
A second full adder (called a modulo adder) adds the summed result of the first full
adder to a modulo value that is stored in its respective modifier register. A third full
adder (called a reverse-carry adder) is also provided.
The offset adder and the reverse-carry adder are in parallel and share common inputs.
The only difference between them is that they carry propagates in opposite directions.
Test logic determines which of the three summed results of the full adders is output.
Each Address ALU can update one address register from its respective address register
file during one instruction cycle. The contents of the associated modifier register
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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