PIC18F010T-I/SN View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18F010T-I/SN

High Performance Microcontrollers

Microchip Technology 

PIC18F010/020

13.0 INSTRUCTION SET SUMMARY

The PIC18F010/020 instruction set adds many

enhancements 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 four 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 PIC18F010/020 instruction set summary in

Table 13-2 lists byte-oriented, bit-oriented, literal

and control operations. Table 13-1 shows the opcode

field descriptions.

Most byte-oriented instructions have three operands:

1. The file register (specified by the value of ’f’)

2. The destination of the result

(specified by the value of ’d’)

3. The accessed memory

(specified by the value of ’a’)

'f' represents a file register designator and 'd' repre-

sents a destination designator. The file register desig-

nator 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 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:

1. The file register (specified by the value of ’f’)

2. The bit in the file register

(specified by the value of ’b’)

3. The accessed memory

(specified by the value of ’a’)

'b' represents a bit field designator which selects the

number of the bit affected by the operation, while 'f' rep-

resents 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 the value of ’k’)

• The desired FSR register to load the literal value

into (specified by the value of ’f’)

• No operand required

(specified by the value of ’—’)

The control instructions may use some of the following

operands:

• A program memory address (specified by the

value of ’n’)

• The mode of the Call or Return instructions (spec-

ified by the value of ’s’)

• The mode of the Table Read and Table Write

instructions (specified by the value of ’m’)

• No operand required

(specified by the value of ’—’)

All instructions are a single word, except for four double

word instructions. These four instructions were made

double word instructions so that all the required infor-

mation is available in these 32-bits. In the second word,

the 4 MSb’s are 1’s. If this second word is executed 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 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. Two

word branch instructions (if true) would take 3 µs.

Figure 13-1 shows the general formats that the instruc-

tions can have.

All examples use the following format to represent a

hexadecimal number:

0xhh

where h signifies a hexadecimal digit.

The Instruction Set Summary, shown in Table 13-2,

lists the instructions recognized by the Microchip

assembler (MPASMTM).

Section 13.1 provides a description of each instruction.

 2001 Microchip Technology Inc.

Preliminary

DS41142A-page 95

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