vi xu ly bui minh thanh 8051 chap3 instruction v1 cuuduongthancong com

Ex: Write a program to move write the content of A to location 32H in internal RAM using 2 methods of addressing: direct addressing and indirect addressing.. Method 1: Direct addressing

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Chapter 3 Instruction Set How to write a program

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• Summary instruction set ( pdf )

• Full instruction set ( pdf )

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The First Program

CuuDuongThanCong.com https://fb.com/tailieudientucntt

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Registers and Data Transfer Instructions

• Register

o Register A = accumulator

o Register B

o Register R0 – R7

• Data Transfer Instruction

o MOV destination, source

Ex:

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Internal RAM

• 128 locations from address 00H to 7FH (256 locations for 8052)

• The content of one location is 8 bit

• Register banks: address 00H to 1FH

• Bit Addressable RAM: address 20H to 2FH

• General purpose RAM: address from 30H to 7FH

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• Address from 30H to 7FH

Ex: MOV A,30H

This instruction moves (reads) the content of location 30H

(NOT data 30H) to register A.

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• Address from 20H to 2FH

• Can read/write a byte or a bit

Ex: MOV 20H, A ; writes the content of register A to location 20H.

9

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• 4 banks: Bank 0 (default), Bank 1, Bank 2, and Bank 3

• Change register bank by selecting bits RS1 and RS0 (in register PSW)

• One bank includes 8 registers: R0 through R7

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Ex: use default bank (Bank 0)

Read the contents of register R5

into the accumulator Read the contents of location 05H into the accumulator

Read the contents of register A

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Register PSW (Program Status Word)

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The active bank is selected by bit RS1 (PSW.4) & RS0 (PSW.3)

Ex: MOV PSW, #00010000B ; select bank 2

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Lê Chí Thông

Special Function Registers (SFRs)

• SFRs include register A, B, PSW, P0, P1, P2, P3, DPTR, TMOD, SCON …

• All SFRs are accessible by name and direct address.

• Both of them must be coded as direct address

Ex: MOV P1, A ; Output register A to Port 1

 Same function BUT different opcodes (A9 E0 vs F9)

Try it: Input Port 2 to register A ……… 17

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Lê Chí Thông

Coding format- Addressing modes

19

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- Source operand is constant

A 1 0 1 1 0 1 0 1

CY 1

DPH 0 0 1 0 0 0 0 0 DPL 0 0 0 0 0 0 0 0

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Direct Addressing

• Access internal RAM and SFRs

MOV A,70H ; copy contents of RAM at 70H to A

MOV R0,40H ; copy contents of RAM at 40H to A

MOV 56H,A ; put contents of A into RAM at 56H

MOV 0D0H,A ; put contents of A into PSW

MOV PSW,A ; same

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Direct Addressing vs Immediate Addressing

Lê Chí Thông

MOV A,30H MOV A,#30H

Direct addressing Immediate addressing

23

≠

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Play with R0-R7 (bank 0) by Direct Addressing

MOV A,4  MOV A,R4

MOV A,7  MOV A,R7

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• The address of the source or destination is specified in registers.

• Use registers R0 or R1 for 8-bit address (internal or external

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Ex: Write a program to move (write) the content of A to location 32H in internal RAM using 2 methods of addressing: direct

addressing and indirect addressing

Method 1: Direct addressing

ORG 0000H MOV 32H,A END

Method 2: Indirect addressing

ORG 0000H MOV R0,#32H MOV @R0,A END

Ex: Write Data to Internal RAM (1)

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Ex: Write Data to Internal RAM (2)

Write a program to move (write) 40H to location 30H in internal RAM using 2 methods of addressing: direct addressing and indirect addressing

ORG 0000H MOV 30H,#40H END

ORG 0000H MOV R0,#30H MOV @R0,#40H END

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Ex: Clear Internal RAM

Ex: Write a program to clear location 31H in internal RAM using 2 methods of addressing: direct addressing and indirect addressing

Hint: to clear means to reset the data to zero

ORG 0000H MOV 31H,#0 END

ORG 0000H MOV R0,#31H MOV @R0,#0 END

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Ex: Write a program to move (read) the content of location 33H in internal RAM to register A using 2 methods of addressing: direct addressing and indirect addressing

ORG 0000H MOV A,33H END

ORG 0000H MOV R0,#33H MOV A,@R0 END

Ex: Read Data from Internal RAM

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Ex: Write a program to move (transfer) the content of internal RAM from address 34H to address 35H, using 2 methods of addressing: direct addressing and indirect addressing

ORG 0000H MOV 35H,34H END

ORG 0000H MOV R0,#34H MOV A,@R0 INC R0

MOV @R0,A END

Ex: Data Transfer (Read/Write)

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• Uses DPTR register for 16-bit addresses (external memory)

• Use @ sign to access the content of the memory location:@DPTR

Ex: MOV DPTR,#4000H ; DPTR  Address

MOVX A,@DPTR ; read content of external RAM at

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Ex: MOV DPTR,#31FFH ; DPTR  Address

MOVX @DPTR,A ; write content of A to external RAM

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Ex: Write a program to move the content of register A to location

0033H in external RAM.

ORG 0000H MOV DPTR,#0033H MOVX @DPTTR,A END

Write Data to External RAM (1)

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Ex: Write a program to write 40H to location 0030H in external

RAM

ORG 0000H MOV A,#40H MOV DPTR,#0030H MOVX @DPTR,A

END

Write Data to External RAM (2)

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Ex: Write a program to clear location 0031H in external RAM

ORG 0000H CLR A

MOV DPTR,#0031H MOVX @DPTTR,A END

Clear External RAM

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Ex: Write a program to read data from external RAM at address

0032 to register A

ORG 0000H MOV DPTR,#0032H MOVX A,@DPTTR END

Read Data from External RAM

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Ex: Write a program to move the content of location 0034H in

external RAM to location 0035H in external RAM.

ORG 0000H MOV DPTR,#0034H MOVX A,@DPTTR INC DPTR

MOVX @DPTR,A END

Read/Write External RAM

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Write a program to move data from internal RAM at address 56H

to external RAM at address 4123H.

ORG 0000HMOV A, 56HMOV DPTR, #4123HMOVX @DPTR, A

END

Your Turn!

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Register Addressing vs Indirect Addressing

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Ex: (Implementation of array)

Clear internal RAM from address

60H to 7FH

MOV R0, #60H LOOP: MOV @R0, #0

INC R0 CJNE R0, #80H, LOOP

Example of Indirect Addressing

R0  60H

(R0)  0 R0  R0+1

R0= 80h?

N

Y

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Write a program to output (send) the content of internal RAM, from address 20H to 45H, to Port 1

ORG 0000H MOV R0, #20H LOOP:

MOV A, @R0 MOV P1, A INC R0 CJNE R0, #46H, LOOP END

Your Turn!

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• Used in SJMP instruction

• A relative address (or offset ) is an 8-bit signed value.

• It is added to PC to form a new value for PC

• Range: -128 ~ +127

• Usually used with label 

Ex: SJMP LABEL1 is in memory

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Ex: SJMP LABEL2 is in memory

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Ex: ORG 0000H

AGAIN: SETB P1.0

NOP NOP CLR P1.0 NOP

SJMP AGAIN END

a Find the opcode of SJMP AGAIN instruction?

b Find the duration of P1.0=1? P1.0=0?

c What is the result of this program?

Your Turn!

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• Used in AJMP, ACALL instruction

Absolute Addressing

Memory map showing 2K pages

Within any 2K page, the upper five address bits are the same for the source and

destination addresses

The lower 11 bits of the destination are supplied in the instruction

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• Used in LCALL and LJMP instruction

• Use full 16-bit address

Ex: LCALL SUBPROGRAM1

LJMP LABEL2

Long Addressing

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• Base address (PC or DPTR) + Offset (A)  Effective Address

• Used with JMP or MOVC

Ex: MOVC A, @A+DPTR

MOVC A, @A+PC

JMP @A+DPTR

Indexed Addressing

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Ex: An even number from 0 to 6 is in the Accumulator The following sequence of instructions branches to one of four AJMP

instructions in a jump table starting at JMP_TBL

MOV DPTR, # JMP_TBL JMP @A + DPTR

JMP_TBL: AJMP LABEL0

AJMP LABEL1 AJMP LABEL2 AJMP LABEL3

• If the Accumulator equals 04H when starting this sequence,

execution jumps to label LABEL2 Because AJMP is a 2-byte

instruction, the jump instructions start at every other address

Indexed Addressing

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8051 Instruction Set Summary

Legend

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Data Transfer

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Data Transfer

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Data Transfer

MOV dest, source ; dest  source

MOV A,#72H ;A=72H MOV R4,#62H ;R4=62H MOV B,0F9H ;B=the content of address F9H of RAM

MOV DPTR,#7634H MOV DPL,#34H

MOV DPH,#76H MOV P1,A ;move (out) A to Port 1

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Creating a Loop (1)

Ex: Write a program to write 40H to internal RAM from location 30H to location 36H.

ORG 0000H MOV 30H,#40H MOV 31H,#40H MOV 32H,#40H MOV 33H,#40H MOV 34H,#40H MOV 35H,#40H MOV 36H,#40H END

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Ex: Write a program to write 40H to internal RAM

from location 30H to location 36H.

(source)

ORG 0000H MOV R5,#7 ;Loop=7 MOV R1,#30H;Address=30H Again: MOV @R1,#40H

INC R1 DEC R5 CJNE R5,#0,Again END

Addr  30H

(Addr)  40H AddrAddr+1

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(source)

ORG 0000H MOV R5,#7;Loop=7 MOV R1,#30H;Address=30H Again: MOV @R1,#40H

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(source)

ORG 0000H MOV R1,#30H;Address=30H Again: MOV @R1,#40H

Addr=37H?

N

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Solutions (1)

Write a program to read data from internal RAM from location 20H

to location 29H and output to Port 1

Method 1: using DJNZ

ORG 0000H MOV R7,#10 MOV R0,#20H Loop:MOV P1,@R0 ;Output to Port1

INC R0 DJNZ R7,loop END

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Solutions (2)

Write a program to read data from internal RAM from location 20H

to location 29H and output to Port 1

Method 2: using CJNE

ORG 0000H MOV R0,#20H Loop:MOV P1,@R0 ;Output to Port1

INC R0 CJNE R0,#2AH,loop END

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MOV A,#ENTRY_NUMBER MOV DPTR,#TABLE

MOVC A,@A+DPTR TABLE: DB data1, data2, data3, …

Look-up Table

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Given a packed-BCD number in location 33H of internal RAM Write

a program that calculate the square of high decade of this number,and store the result in internal RAM at address 34H

ORG 0 MOV A,33H SWAP A

ANL A,#0FH MOV DPTR,#TABLE MOVC A,@A+DPTR MOV 34H, A

TABLE:

DB 0,1,4,9,16,25,36,49,64,81 END

Look-up Table - Example

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Given a packed-BCD number in location 34H of internal RAM Write

a program that displays the low decade of this number on thecommon-anode 7-seg LED connected to Port 2 (schematic)

Your Turn!

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D4 e

D3 d

D2 c

D1 b

D0 a

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ORG 0000HMOV 34H,#25HMOV A,34H

ANL A,#0FHMOV DPTR,#TABLEMOVC A,@A+DPTRMOV P2,A

SJMP DONETABLE: DB 40h,79h,24h,30h,19h

DB 12h,02h,78h,00h,10hDONE: NOP

END(source)

Solutions

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MOV A, #ENTRY_NUMBER CALL LOOK_UP

…

LOOK_UP:

INC A MOVC A, @A+PC RET

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MOV DPTR,#JUMP_TABLE MOV A,INDEX_NUMBER

RL A JMP @A+DPTR

… JUMP_TABLE: AJMP CASE0

AJMP CASE1 AJMP CASE2

…

Jump Table

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Arithmetic Operations

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Flag Effect

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Arithmetic Operations (1)

ADD A,#34H ; Immediate addressing A  A + 34H

ADD A,34H ;Direct addressing A  A + (34H)

ADD A,R1 ;Register addressing A  A + R1

ADD A,@R1 ;Indirect addressing A  A + (R1)

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Your Turn!

Given 10 8-bit unsigned numbers in internal RAM at starting

address 30H Write a program to calculate the sum of these

numbers and store the result in internal RAM at address 2FH

Assume that the result is less than or equal 255

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Given 10 8-bit unsigned numbers in internal RAM at starting

address 30H Write a program to calculate the sum of these

numbers and store the result in internal RAM at address 2FH

Assume that the result is less than or equal 255

ORG 0 MOV R0,#30H CLR A

MOV R2,#10 loop: ADD A,@R0

INC R0 DJNZ R2,loop MOV 2FH,A END

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• Rotate instructions operate only on A

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• Note that a shift left is the same as

multiplying by 2, shift right is divide by 2

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Logic Operations

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Logic Operations (1)

MOV A,#46H MOV R3,A ANL A,#0FH MOV R7,A MOV A,R3 ANL A,#0F0H SWAP A

MOV R6,A

R6 = ……….; R7 = ……….

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Logic Operations (2)

MOV R2,#05H MOV R3,#07H MOV A,R2

SWAP A ORL A,R3

 A = ……….

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Boolean Variable

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Boolean Variable

ORG 0 LOOP: MOV C,P1.0

ANL C,P1.1 MOV P1.2,C SJMP LOOP END

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Your Turn!

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ORG 0 LOOP: MOV C,P1.4

CPL C ANL C,P1.5 CPL C

ORL C,P1.6 MOV P1.7,C SJMP LOOP

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Program Branching

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Program Branching

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SJMP : 8-bit offset LJMP : 11-bit address (2KB segment) AJMP : 16-bit

Unconditional

jumps

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Conditional Jumps

JNZ Jump if A ≠ 0

DJNZ Decrement and jump if ≠ 0

CJNE A,byte Jump if A ≠ byte

CJNE reg,#data Jump if byte ≠ #data

JNC Jump if CY=0

JB Jump if bit=1

JNB Jump if bit=0

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ACALL (absolute call)

ACALL is 2-byte instruction the target address of the

subroutine must be within 2K byte range.

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• Call is similar to a jump, but

– Call pushes PC on stack before branching

ACALL <address ll> ; stack  PC

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• Return is also similar to a jump, but

– Return instruction pops PC from stack to get

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MAIN: .

ACALL SUBLABEL

SUBLABEL:

RET the subroutine

call to the subroutine

Subroutines

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DJNZ – a For loop

Use DJNZ to create a for loop control

Ex: a 10-time loop

MOV R7,#10

…

… (end loop)

DJNZ R7,LOOP

(continue)

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DJNZ – a For loop

Use DJNZ to create a 1000-time loop?

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DJNZ – an example

Ex: Write a program to write 40H to internal

RAM from location 30H to location 36H.

(source)

ORG 0000H MOV R5,#7;Loop=7 MOV R1,#30H;Address=30H Again: MOV @R1,#40H

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Write a program to clear ACC, then add 3 to the

accumulator ten times.

Solution:

MOV A,#0 MOV R2,#10

DJNZ R2,AGAIN ;repeat until R2=0 (10 times) MOV R5,A

DJNZ – another example

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Write a program to copy a block of 10 bytes from RAM

location starting at 37h to RAM location starting at 59h.

DJNZ – Your Turn!

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Write a program to copy a block of 10 bytes from RAM

location starting at 37h to RAM location starting at 59h.

Solution:

L1: MOV A,@R0

MOV @R1,A INC R0

INC R1 DJNZ R2,L1

Solutions

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ORG 0LOOP: SETB P1.0

ACALL DELAYCLR P1.0

ACALL DELAYSJMP LOOPDELAY: MOV R6,#200

DL1: MOV R7,#250

DJNZ R7,$

DJNZ R6,DL1RET

END(source)

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ORG 0LOOP: SETB P1.0

ACALL DELAYCLR P1.0

ACALL DELAYSJMP LOOPDELAY: MOV R6,#200

DL1: MOV R7,#250 1MC x 1

DJNZ R7,$ 2 MC x 250DJNZ R6,DL1

RETEND

Blinky Program

501 MC

Tiêu đề	The 8051 Microcontroller Chapter 3 Instruction Set
Tác giả	Lê Chí Thông
Trường học	Ho Chi Minh City University of Technology
Chuyên ngành	Embedded Systems / Microcontrollers
Thể loại	Lecture Notes
Thành phố	Ho Chi Minh City

Định dạng
Số trang	138
Dung lượng	3,27 MB