DSPIC33FJ256MC710-IPT Datasheet, PDF (34/90 Pages) Microchip Technology – dsPIC® DSC High-Performance 16-Bit Digital Signal Controllers

dsPIC33F
9.0 dsPIC33F INSTRUCTION SET
9.1 Introduction
The dsPIC33F instruction set provides a broad suite of
instructions which supports traditional microcontroller
applications, and a class of instructions which supports
math-intensive applications. Since almost all of the
functionality of the PICmicro^® MCU instruction set has
been maintained, this hybrid instruction set allows a
friendly DSP migration path for users already familiar
with the PICmicro microcontroller.
9.2 Instruction Set Overview
The dsPIC33F instruction set contains 84 instructions
which can be grouped into the ten functional categories
shown in Table 9-1. Table 9-2 defines the symbols
used in the instruction summary tables, Table 9-3
through Table 9-12. These tables define the syntax,
description, storage and execution requirements
for each instruction. Storage requirements are repre-
sented in 24-bit instruction words and execution
requirements are represented in instruction cycles.
Most instructions have several different addressing
modes and execution flows which require different
instruction variants. For instance, there are six unique
ADD instructions and each instruction variant has its
own instruction encoding.
TABLE 9-1: dsPIC33F INSTRUCTION
GROUPS
Functional Group
Summary Table
Move Instructions
Math Instructions
Logic Instructions
Rotate/Shift Instructions
Bit Instructions
Compare/Skip Instructions
Program Flow Instructions
Shadow/Stack Instructions
Control Instructions
DSP Instructions
Table 9-3
Table 9-4
Table 9-5
Table 9-6
Table 9-7
Table 9-8
Table 9-9
Table 9-10
Table 9-11
Table 9-12
9.2.1 MULTI-CYCLE INSTRUCTIONS
As the instruction summary tables show, most
instructions execute in a single cycle with the following
exceptions:
• Instructions DO, MOV.D, POP.D, PUSH.D,
TBLRDH, TBLRDL, TBLWTH and TBLWTL
require 2 cycles to execute.
• Instructions DIVF, DIV.S, DIV.U are single-
cycle instructions, which should be executed
18 consecutive times as the target REPEAT
instruction.
• Instructions that change the program counter also
require 2 cycles to execute, with the extra cycle
executed as a NOP. Skip instructions, which skip
over a 2-word instruction, require 3 instruction
cycles to execute with 2 cycles executed as a
NOP.
• The RETFIE, RETLW and RETURN are special
cases of instructions that change the program
counter. These execute in 3 cycles unless an
exception is pending, and then they execute in
2 cycles.
Note:
Instructions that access program memory
as data, using Program Space Visibility,
incur some cycle count overhead.
9.2.2 MULTI-WORD INSTRUCTIONS
As the instruction summary tables show, almost all
instructions consume one instruction word (24 bits),
with the exception of the CALL, DO and GOTO
instructions, which are flow instructions listed in
Table 9-9. These instructions require two words of
memory because their opcodes embed large literal
operands.
DS70155C-page 32
Preliminary
© 2005 Microchip Technology Inc.