PIC16C5X
All instructions are executed within one single
instruction cycle, unless a conditional test is true or the
8.0
INSTRUCTION SET SUMMARY
Each PIC16C5X 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 PIC16C5X instruction set summary in
Table 8-2 groups the instructions into byte-oriented,
bit-oriented, and literal and control operations. Table 8-1
shows the opcode field descriptions.
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.
For byte-oriented instructions, 'f' represents a file register
designator and 'd' represents a destination designator.The
file register designator is used to specify which one of the
32 file registers is to be used by the instruction.
Figure 8-1 shows the three general formats that the
instructions can have. All examples in the figure use the
following format to represent a hexadecimal number:
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.
0xhhh
where 'h' signifies a hexadecimal digit.
FIGURE 8-1: GENERAL FORMAT FOR
INSTRUCTIONS
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.
Byte-oriented file register operations
11
6
5
4
0
OPCODE
d
f (FILE #)
For literal and control operations, 'k' represents an
8 or 9-bit constant or literal value.
d = 0 for destination W
d = 1 for destination f
f = 5-bit file register address
Bit-oriented file register operations
11 8 7
b (BIT #)
TABLE 8-1:
OPCODE FIELD
DESCRIPTIONS
5
4
0
Field
Description
OPCODE
f (FILE #)
f
W
b
k
Register file address (0x00 to 0x7F)
Working register (accumulator)
b = 3-bit bit address
f = 5-bit file register address
Bit address within an 8-bit file register
Literal field, constant data or label
Literal and control operations (except GOTO)
11
Don't care location (= 0 or 1)
8
7
0
The assembler will generate code with x = 0. It is
the recommended form of use for compatibility
with all Microchip software tools.
x
d
OPCODE
k (literal)
k = 8-bit immediate value
Literal and control operations - GOTOinstruction
11 0
Destination select;
d = 0 (store result in W)
d = 1 (store result in file register 'f')
Default is d = 1
9
8
OPCODE
k (literal)
label Label name
TOS
PC
Top of Stack
k = 9-bit immediate value
Program Counter
Watchdog Timer Counter
Time-Out bit
WDT
TO
PD
Power-Down bit
Destination, either the W register or the specified
register file location
dest
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Register bit field
In the set of
italics
User defined term (font is courier)
1998 Microchip Technology Inc.
Preliminary
DS30453B-page 43
MICROCHIP [ MICROCHIP ]
