PIC16F720-ESLASHML datasheet(173/244 Pages) MICROCHIP

173 / 244 page

 2010 Microchip Technology Inc.

DS41430A-page 173

PIC16F/LF720/721

21.0

INSTRUCTION SET SUMMARY

The PIC16F/LF720/721

instruction set

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 21-1, while the various opcode

fields are summarized in Table 21-1.

Table 21-2 lists the instructions recognized by the

MPASMTM assembler.

For byte-oriented instructions, ‘f’ represents a file

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

nominal

instruction

execution

time

s. 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.

21.1

Read-Modify-Write Operations

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.

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 consequence of clearing the condition that set

the RABIF flag.

FIGURE 21-1:

GENERAL FORMAT FOR

INSTRUCTIONS

TABLE 21-1:

OPCODE FIELD

DESCRIPTIONS

Field

Description

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

Carry bit

Digit carry bit

Zero bit

Power-down bit

Byte-oriented file register operations

d = 0 for destination W

OPCODE

f (FILE #)

d = 1 for destination f

f = 7-bit file register address

Bit-oriented file register operations

10 9

7 6

OPCODE

b (BIT #)

f (FILE #)

b = 3-bit bit address

f = 7-bit file register address

Literal and control operations

OPCODE

k (literal)

k = 8-bit immediate value

OPCODE

k (literal)

k = 11-bit immediate value

General

CALL

and GOTO instructions only

PIC16F720-E/ML bảng dữ liệu(PDF) 173 Page - Microchip Technology

PIC16F720-E/ML bảng dữ liệu(HTML) 173 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

bảng dữ liệu tải về

Link URL