70291E Datasheet, PDF (332/436 Pages) Microchip Technology – High-Performance, 16-bit Digital Signal Controllers

dsPIC33FJ32MC302/304, dsPIC33FJ64MCX02/X04 AND dsPIC33FJ128MCX02/X04
Most instructions are a single word. Certain double-
word instructions are designed to provide all the
required information in these 48 bits. In the second
word, the 8 MSbs are ‘0’s. If this second word is exe-
cuted as an instruction (by itself), it executes as a NOP.
The double-word instructions execute in two instruction
cycles.
Most single-word instructions are executed in a single
instruction cycle, unless a conditional test is true, or the
program counter is changed as a result of the
instruction. In these cases, the execution takes two
instruction cycles with the additional instruction cycle(s)
executed as a NOP. Notable exceptions are the BRA
(unconditional/computed branch), indirect CALL/GOTO,
all table reads and writes and RETURN/RETFIE
instructions, which are single-word instructions but take
two or three cycles. Certain instructions that involve
skipping over the subsequent instruction require either
two or three cycles if the skip is performed, depending
on whether the instruction being skipped is a single-word
or two-word instruction. Moreover, double-word moves
require two cycles.
Note:
For more details on the instruction set,
refer to the “16-bit MCU and DSC
Programmer’s Reference Manual”
(DS70157).
TABLE 29-1: SYMBOLS USED IN OPCODE DESCRIPTIONS
Field
Description
#text
(text)
[text]
{}
<n:m>
.b
.d
.S
.w
Acc
AWB
bit4
C, DC, N, OV, Z
Expr
f
lit1
lit4
lit5
lit8
lit10
lit14
lit16
lit23
None
OA, OB, SA, SB
PC
Slit10
Slit16
Slit6
Wb
Wd
Wdo
Wm,Wn
Wm*Wm
Means literal defined by “text”
Means “content of text”
Means “the location addressed by text”
Optional field or operation
Register bit field
Byte mode selection
Double-Word mode selection
Shadow register select
Word mode selection (default)
One of two accumulators {A, B}
Accumulator write back destination address register ∈ {W13, [W13]+ = 2}
4-bit bit selection field (used in word addressed instructions) ∈ {0...15}
MCU Status bits: Carry, Digit Carry, Negative, Overflow, Sticky Zero
Absolute address, label or expression (resolved by the linker)
File register address ∈ {0x0000...0x1FFF}
1-bit unsigned literal ∈ {0,1}
4-bit unsigned literal ∈ {0...15}
5-bit unsigned literal ∈ {0...31}
8-bit unsigned literal ∈ {0...255}
10-bit unsigned literal ∈ {0...255} for Byte mode, {0:1023} for Word mode
14-bit unsigned literal ∈ {0...16384}
16-bit unsigned literal ∈ {0...65535}
23-bit unsigned literal ∈ {0...8388608}; LSb must be ‘0’
Field does not require an entry, can be blank
DSP Status bits: ACCA Overflow, ACCB Overflow, ACCA Saturate, ACCB Saturate
Program Counter
10-bit signed literal ∈ {-512...511}
16-bit signed literal ∈ {-32768...32767}
6-bit signed literal ∈ {-16...16}
Base W register ∈ {W0...W15}
Destination W register ∈ { Wd, [Wd], [Wd++], [Wd--], [++Wd], [--Wd] }
Destination W register ∈
{ Wnd, [Wnd], [Wnd++], [Wnd--], [++Wnd], [--Wnd], [Wnd+Wb] }
Dividend, Divisor working register pair (direct addressing)
Multiplicand and Multiplier working register pair for Square instructions ∈
{W4 * W4,W5 * W5,W6 * W6,W7 * W7}
DS70291E-page 332
© 2011 Microchip Technology Inc.