RFPIC12F675H Microchip Technology Inc., RFPIC12F675H Datasheet - Page 75

• Manufacturer Part Number: RFPIC12F675H
• Description: 20-pin Flash-based 8-bit Cmos Microcontroller With Uhf Ask/fsk Transmitter
• Manufacturer: Microchip Technology Inc.

11.0
The rfPIC12F675 instruction set is highly orthogonal
and is comprised of three basic categories:
• Byte-oriented operations
• Bit-oriented operations
• Literal and control operations
Each rfPIC12F675 instruction is a 14-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 11-1, while the
various opcode fields are summarized in Table 11-1.
Table 11-2 lists the instructions recognized by the
MPASM
each instruction is also available in the PICmicro™
Mid-Range Reference Manual (DS33023).
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 zero, the result is
placed in the W register. If ‘d’ is one, 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 bit affected by the
operation, while ‘f’ represents the address of the file in
which the bit is located.
For literal and control operations, ‘k’ represents an
8-bit or 11-bit constant, or literal value.
One instruction cycle consists of four oscillator periods;
for an oscillator frequency of 4 MHz, this gives a normal
instruction execution time of 1 µs. 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. When this occurs,
the execution takes two instruction cycles, with the
second cycle executed as a NOP.
All instruction examples use the format ‘0xhh’ to
represent a hexadecimal number, where ‘h’ signifies
a hexadecimal digit.
11.1
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.
 2003 Microchip Technology Inc.
Note:
TM
INSTRUCTION SET SUMMARY
READ-MODIFY-WRITE
OPERATIONS
To maintain upward compatibility with
future products, do not use the OPTION
and TRISIO instructions.
assembler. A complete description of
Preliminary
For example, a CLRF GPIO instruction will read GPIO,
clear all the data bits, then write the result back to
GPIO. This example would have the unintended result
that the condition that sets the GPIF flag would be
cleared.
TABLE 11-1:
FIGURE 11-1:
f
W
b
k
x
d
PC
TO
PD
Field
Byte-oriented file register operations
Bit-oriented file register operations
Literal and control operations
General
CALL and GOTO instructions only
13
13
13
13
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.
Program Counter
Time-out bit
Power-down bit
OPCODE
d = 0 for destination W
d = 1 for destination f
f = 7-bit file register address
b = 3-bit bit address
f = 7-bit file register address
k = 8-bit immediate value
k = 11-bit immediate value
OPCODE
OPCODE
OPCODE
11
OPCODE FIELD
DESCRIPTIONS
rfPIC12F675
10
10 9
GENERAL FORMAT FOR
INSTRUCTIONS
8
Description
b (BIT #)
7
d
8
6
7
7 6
k (literal)
f (FILE #)
k (literal)
DS70091A-page 73
f (FILE #)
0
0
0
0