PIC16F526 Datasheet, PDF (71/122 Pages) Microchip Technology – 14-Pin, 8-Bit Flash Microcontroller

12.0 INSTRUCTION SET SUMMARY
The PIC16 instruction set is highly orthogonal and is
comprised of three basic categories.
• Byte-oriented operations
• Bit-oriented operations
• Literal and control operations
Each PIC16 instruction is a 12-bit word divided into an
opcode, which specifies the instruction type, and one
or more operands which further specify the operation
of the instruction. The formats for each of the
categories is presented in Figure 12-1, while the
various opcode fields are summarized in Table 12-1.
For byte-oriented instructions, ‘f’ represents a file
register designator and ‘d’ represents a destination
designator. The file register designator specifies which
file register is to be used by the instruction.
The destination designator specifies where the result of
the operation is to be placed. If ‘d’ is ‘0’, the result is
placed in the W register. If ‘d’ is ‘1’, the result is placed
in the file register specified in the instruction.
For bit-oriented instructions, ‘b’ represents a bit field
designator which selects the number of the bit affected
by the operation, while ‘f’ represents the number of the
file in which the bit is located.
For literal and control operations, ‘k’ represents an
8 or 9-bit constant or literal value.
TABLE 12-1: OPCODE FIELD
DESCRIPTIONS
Field
f
W
b
k
x
d
label
TOS
PC
WDT
TO
PD
dest
[]
()
Æ
<>
Œ
italics
Description
Register file address (0x00 to 0x7F)
Working register (accumulator)
Bit address within an 8-bit file register
Literal field, constant data or label
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.
Destination select;
d = 0 (store result in W)
d = 1 (store result in file register ‘f’)
Default is d = 1
Label name
Top-of-Stack
Program Counter
Watchdog Timer counter
Time-out bit
Power-down bit
Destination, either the W register or the specified
register file location
Options
Contents
Assigned to
Register bit field
In the set of
User defined term (font is courier)
 2010 Microchip Technology Inc.
PIC16F526
All instructions are executed within a single instruction
cycle, unless a conditional test is true or the program
counter is changed as a result of an instruction. In this
case, the execution takes two instruction cycles. One
instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 s. If a conditional test is
true or the program counter is changed as a result of an
instruction, the instruction execution time is 2 s.
Figure 12-1 shows the three general formats that the
instructions can have. All examples in the figure use
the following format to represent a hexadecimal
number:
0xhhh
where ‘h’ signifies a hexadecimal digit.
FIGURE 12-1:
GENERAL FORMAT FOR
INSTRUCTIONS
Byte-oriented file register operations
11
654
0
OPCODE
d
f (FILE #)
d = 0 for destination W
d = 1 for destination f
f = 5-bit file register address
Bit-oriented file register operations
11
87 5 4
0
OPCODE
b (BIT #) f (FILE #)
b = 3-bit bit address
f = 5-bit file register address
Literal and control operations (except GOTO)
11
87
0
OPCODE
k (literal)
k = 8-bit immediate value
Literal and control operations – GOTO instruction
11
98
0
OPCODE
k (literal)
k = 9-bit immediate value
DS41326D-page 71