Datasheet

 2010-2013 Microchip Technology Inc. DS40001452D-page 263
PIC16(L)F1516/7/8/9
24.0 INSTRUCTION SET SUMMARY
Each instruction is a 14-bit word containing the opera-
tion code (opcode) and all required operands. The
opcodes are broken into three broad categories.
• Byte Oriented
• Bit Oriented
• Literal and Control
The literal and control category contains the most
varied instruction word format.
Table 24-3 lists the instructions recognized by the
MPASM
TM
assembler.
All instructions are executed within a single instruction
cycle, with the following exceptions, which may take
two or three cycles:
• Subroutine takes two cycles (CALL, CALLW)
• Returns from interrupts or subroutines take two
cycles (RETURN, RETLW, RETFIE)
• Program branching takes two cycles (GOTO, BRA,
BRW, BTFSS, BTFSC, DECFSZ, INCSFZ)
• One additional instruction cycle will be used when
any instruction references an indirect file register
and the file select register is pointing to program
memory.
One instruction cycle consists of four oscillator cycles;
for an oscillator frequency of 4 MHz, this gives a
nominal instruction execution rate of 1 MHz.
All instruction examples use the format ‘0xhh’ to
represent a hexadecimal number, where ‘h’ signifies a
hexadecimal digit.
24.1 Read-Modify-Write Operations
Any instruction that specifies a file register as part of
the instruction performs a Read-Modify-Write (R-M-W)
operation. The register is read, the data is modified,
and the result is stored according to either the instruc-
tion, or the destination designator ‘d’. A read operation
is performed on a register even if the instruction writes
to that register.
TABLE 24-1: OPCODE FIELD
DESCRIPTIONS
TABLE 24-2: ABBREVIATION
DESCRIPTIONS
Field Description
f
Register file address (0x00 to 0x7F)
W
Working register (accumulator)
b
Bit address within an 8-bit file register
k
Literal field, constant data or label
x
Don’t care location (= 0 or 1).
The assembler will generate code with x = 0.
It is the recommended form of use for
compatibility with all Microchip software tools.
d
Destination select; d = 0: store result in W,
d = 1: store result in file register f.
Default is d = 1.
n
FSR or INDF number. (0-1)
mm
Pre-post increment-decrement mode
selection
Field Description
PC
Program Counter
TO
Time-out bit
C
Carry bit
DC
Digit carry bit
Z
Zero bit
PD
Power-down bit