PIC16LF1904 Datasheet, PDF (223/288 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt XLP Technology

21.0 INSTRUCTION SET SUMMARY
Each PIC16 instruction is a 14-bit word containing the
operation 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 var-
ied instruction word format.
Table 21-3 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 4 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.
PIC16LF1904/6/7
21.1 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 21-1: OPCODE FIELD
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
TABLE 21-2: ABBREVIATION
DESCRIPTIONS
Field
Description
PC Program Counter
TO Time-out bit
C Carry bit
DC Digit carry bit
Z Zero bit
PD Power-down bit
 2011 Microchip Technology Inc.
Preliminary
DS41569A-page 223