ST72F324K6B5 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72F324K6B5

8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE

STMicroelectronics 

ST72324

11 INSTRUCTION SET

11.1 CPU ADDRESSING MODES

The CPU features 17 different addressing modes

which can be classified in 7 main groups:

Addressing Mode

Inherent

Immediate

Direct

Indexed

Indirect

Relative

Bit operation

Example

nop

ld A,#$55

ld A,$55

ld A,($55,X)

ld A,([$55],X)

jrne loop

bset byte,#5

The CPU Instruction set is designed to minimize

the number of bytes required per instruction: To do

so, most of the addressing modes may be subdi-

vided in two sub-modes called long and short:

– Long addressing mode is more powerful be-

cause it can use the full 64 Kbyte address space,

however it uses more bytes and more CPU cy-

cles.

– Short addressing mode is less powerful because

it can generally only access page zero (0000h -

00FFh range), but the instruction size is more

compact, and faster. All memory to memory in-

structions use short addressing modes only

(CLR, CPL, NEG, BSET, BRES, BTJT, BTJF,

INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)

The ST7 Assembler optimizes the use of long and

short addressing modes.

Table 23. CPU Addressing Mode Overview

Mode

Inherent

Immediate

Syntax

nop

ld A,#$55

Destination

Pointer

Address

(Hex.)

Pointer Size

(Hex.)

Length

(Bytes)

+0

+1

Short

Direct

ld A,$10

00..FF

+1

Long

Direct

ld A,$1000

0000..FFFF

+2

No Offset Direct Indexed ld A,(X)

00..FF

+0

Short

Direct Indexed ld A,($10,X)

00..1FE

+1

Long

Direct Indexed ld A,($1000,X)

0000..FFFF

+2

Short

Long

Indirect

Indirect

ld A,[$10]

00..FF

00..FF

byte

+2

ld A,[$10.w]

0000..FFFF 00..FF

word

+2

Short

Indirect Indexed ld A,([$10],X)

00..1FE

00..FF

byte

+2

Long

Indirect Indexed ld A,([$10.w],X) 0000..FFFF 00..FF

word

+2

Relative

Direct

jrne loop

PC+/-127

+1

Relative

Bit

Indirect

Direct

jrne [$10]

PC+/-127 00..FF

byte

+2

bset $10,#7

00..FF

+1

Bit

Indirect

bset [$10],#7

00..FF

00..FF

byte

+2

Bit

Direct Relative btjt $10,#7,skip 00..FF

+2

Bit

Indirect Relative btjt [$10],#7,skip 00..FF

00..FF

byte

+3

107/161

Share Link: