PIC12F510/16F506
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 μs. If a conditional test is
true or the program counter is changed as a result of an
instruction, the instruction execution time is 2 μs.
11.0 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 catego-
ries is presented in Figure 11-1, while the various
opcode fields are summarized in Table 11-1.
Figure 11-1 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
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.
where ‘h’ signifies a hexadecimal digit.
FIGURE 11-1:
GENERAL FORMAT FOR
INSTRUCTIONS
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.
Byte-oriented file register operations
11
6
5
d
4
0
OPCODE
f (FILE #)
For bit-oriented instructions, ‘b’ represents a bit field
designator which selects the number of the bits
affected by the operation, while ‘f’ represents the
number of the file in which the bit is located.
d = 0for destination W
d = 1for destination f
f = 5-bit file register address
Bit-oriented file register operations
11 8 7
b (BIT #)
For literal and control operations, ‘k’ represents an
8 or 9-bit constant or literal value.
5
4
0
OPCODE
f (FILE #)
b = 3-bit bit address
f = 5-bit file register address
TABLE 11-1: OPCODE FIELD
DESCRIPTIONS
Literal and control operations (except GOTO)
11
Field
Description
f
W
b
k
x
Register file address (0x00 to 0x7F)
Working register (accumulator)
8
7
0
OPCODE
k (literal)
Bit address within an 8-bit file register
Literal field, constant data or label
k = 8-bit immediate value
Don’t care location (= 0or 1)
Literal and control operations – GOTOinstruction
11
The assembler will generate code with x = 0. It is the
recommended form of use for compatibility with all
Microchip software tools.
9
8
0
OPCODE
k (literal)
d
Destination select;
d= 0(store result in W)
d= 1(store result in file register ‘f’)
Default is d= 1
k = 9-bit immediate value
label
TOS
PC
Label name
Top-of-Stack
Program Counter
Watchdog Timer counter
WDT
TO
Time-out bit
PD
Power-down bit
dest
Destination, either the W register or the specified
register file location
[
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Options
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Register bit field
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© 2006 Microchip Technology Inc.
Preliminary
DS41268B-page 71
ETC [ ETC ]
