PIC16F872-I/SP Microchip Technology Inc., PIC16F872-I/SP Datasheet - Page 105

• Manufacturer Part Number: PIC16F872-I/SP
• Description: 28 PIN, 7 KB FLASH, 128 RAM, 22 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F872-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 64 Bytes
• Input Output: 22
• Interface: I2C/SPI
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

12.0
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 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 12-1, while the various opcode
fields are summarized in Table 12-1.
Table 13-2 lists the instructions recognized by the
MPASM
instruction is also available in the PICmicro™ Mid-
Range Reference Manual (DS33023).
For byte-oriented instructions, ‘f’ represents a file reg-
ister designator and ‘d’ represents a destination desig-
nator. 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 opera-
tion, while ‘f’ represents the address of the file in which
the bit is located.
For literal and control operations, ‘k’ represents an
eight- or eleven-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 con-
ditional test is true or the program counter is changed
as a result of an instruction. When this occurs, the exe-
cution takes two instruction cycles with the second
cycle executed as a NOP.
All instruction examples use the format ‘0xhh’ to repre-
sent a hexadecimal number, where ‘h’ signifies a hexa-
decimal digit.
12.1
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.
© 2006 Microchip Technology Inc.
Note:
TM
INSTRUCTION SET SUMMARY
READ-MODIFY-WRITE
OPERATIONS
Assembler. A complete description of each
To maintain upward compatibility with
future PIC16F872 products, do not use the
OPTION and TRIS instructions.
For example, a “CLRF PORTB” instruction will read
PORTB, clear all the data bits, then write the result
back to PORTB. This example would have the unin-
tended result that the condition that sets the RBIF flag
would be cleared.
TABLE 12-1:
FIGURE 12-1:
Field
f
W
b
k
x
d
PC
TO
PD
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
10
10 9
GENERAL FORMAT FOR
INSTRUCTIONS
8
Description
b (BIT #)
PIC16F872
7
d
8
6
7
7 6
k (literal)
DS30221C-page 103
f (FILE #)
k (literal)
f (FILE #)
0
0
0
0