PIC18F4539-I/ML【PDF 128/322 页】IC MCU FLASH 12KX16 EE A/D 44QFN

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录3882

124页 125页 126页 127页 [128页]129页 130页 131页 132页

2002 Microchip Technology Inc.

Preliminary

DS30485A-page 211

PIC18FXX39

21.0 INSTRUCTION SET SUMMARY

The PIC18FXXX instruction set adds many enhance-

ments to the previous PICmicro instruction sets, while

maintaining an easy migration from these PICmicro

instruction sets.

Most instructions are a single program memory word

(16-bits), but there are three instructions that require

two program memory locations.

Each single word instruction is a 16-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 instruction set is highly orthogonal and is grouped

into four basic categories:

Byte-oriented operations

Bit-oriented operations

Literal operations

Control operations

The PIC18FXXX instruction set summary in Table 21-2

lists byte-oriented, bit-oriented, literal and control

operations. Table 21-1 shows the opcode field

descriptions.

Most byte-oriented instructions have three operands:

The file register (specified by ‘f’)

The destination of the result

(specified by ‘d’)

The accessed memory

(specified by ‘a’)

The file register designator 'f' specifies which file

The destination designator ‘d’ specifies where the

result of the operation is to be placed. If 'd' is zero, the

result is placed in the WREG register. If 'd' is one, the

result is placed in the file register specified in the

instruction.

All bit-oriented instructions have three operands:

The file register (specified by ‘f’)

The bit in the file register

(specified by ‘b’)

The accessed memory

(specified by ‘a’)

The bit field designator 'b' selects the number of the bit

affected by the operation, while the file register desig-

nator 'f' represents the number of the file in which the

bit is located.

The literal instructions may use some of the following

operands:

A literal value to be loaded into a file register

(specified by ‘k’)

The desired FSR register to load the literal value

into (specified by ‘f’)

No operand required

(specified by ‘—’)

The control instructions may use some of the following

operands:

A program memory address (specified by ‘n’)

The mode of the Call or Return instructions

(specified by ‘s’)

The mode of the Table Read and Table Write

instructions (specified by ‘m’)

No operand required

(specified by ‘—’)

All instructions are a single word, except for three dou-

ble-word instructions. These three instructions were

made double-word instructions, so that all the required

information is available in these 32 bits. In the second

word, the 4 MSbs are ‘1’s. If this second word is exe-

cuted as an instruction (by itself), it will execute as a

NOP

All single word instructions are executed in a single

instruction cycle, unless a conditional test is true or the

program counter is changed as a result of the instruc-

tion. In these cases, the execution takes two instruction

cycles with the additional instruction cycle(s) executed

as a NOP.

The double-word instructions execute in 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

s. If a conditional test is

true, or the program counter is changed as a result of

an instruction, the instruction execution time is 2

Two-word branch instructions (if true) would take 3

Figure 21-1 shows the general formats that the

instructions can have.

All examples use the format ‘nnh’ to represent a hexa-

decimal number, where ‘h’ signifies a hexadecimal

digit.

The Instruction Set Summary, shown in Table 21-2,

lists the instructions recognized by the Microchip

Assembler (MPASMTM).

Section 21.1 provides a description of each instruction.

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式