Student WorksheetCompaqCompaq322009-08-23T09:16:00Z2009-08-23T09:25:00Z17304161iLLUSiON349488211.6359

Student Worksheet

Assembly Language Programming

Applied Physics Department, Faculty of Science, KMITL

LAB 2 8051 Programming Registers

Student ID

Name

Date

Tools and Materials1. MTK51 8051 Microcontroller Trainer Kit

Table 2-1. Location of the 8051 registers

Registers

Location

Function

80H*

Port 0

81H

Stack Pointer

DPL

82H

Data Pointer (Low byte)

DPH

83H

Data Pointer (High byte)

TCON

88H*

Timer Control

TMOD

89H

Timer Mode

TL0

8AH

Timer0 Low byte

TH0

8CH

Timer0 High byte

TL1

8BH

Timer1 Low byte

TH1

8DH

Timer1 High byte

90H*

Port 1

SCON

98H*

Serial

Port

Control

SBUF

99H

Serial

Port

Data

A0H*

Port 2

A8H*

Interrupt Enable Register

B0H*

Port 3

B8H*

Interrupt Priority

PSW

D0H*

Program Status Word

ACC

E0H*

Accumulator

F0H*

B register

*bit addressable register. The bit address can find by adding 0-7 to the byte address, e.g. bit 7 of PORT P1 is 90H+07=97H (P1.7).

R0-R7 are general purpose registers and the shown locations (00-07) are for BANK0.

Exercises1. Find the HEX code of below instructions using Table 2-1 and the 8051 instruction sheet.2. Enter the HEX code to the MTK51 memory and use

Single Step running. Find the answer below.

Move data one byte from external memory to internal memoryADDRESSHEX codeLabelInstructionComment9000STARTMOV DPTR,#E000HMOVX A,@DPTRMOV R0, AA=?MOV R1,#30HR1=?MOV @R1,A[30H]=?[E000H]=?Q. If we change the location from E000H to 9000H, what is the data written to location 30H?A._____________________________________________________________Instead of reading the data from external memory and write to the internal memory, write the code that reads data at location 31H (internal) and write it to external memory at location E001H.Handcode and test it with single step.ADDRESSHEX codeLabelInstructionComment9000STARTQ. After the code has been executed, what is the data at location 31H (internal) and E001H (external)?A. [31H]=______________________ [E001H]= ________________________

GPIO3 indicates accumulator content in single step runningADDRESSHEX codeLabelInstructionComment9000MOV A,#0 A=?LOOPINC AA=?80 XXSJMP LOOPXX=?Offset byte calculation can be computed using ALT OFFSETFinding by hand calculation is done by,OFFSET=DESTINATION-PC.The DESTINATION is the location where we will jump to and the PC is current program counter after the jump instruction has been fetched.For example if the DESTINATION is 9002 and the PC is 9005. The OFFSET will be 9002-9005=-3. We make the signed number easily using 2’s complement notation.Here is the positive number 3 in 8-bit binary, 0000 0011. We make -3 by 2’s complement. 1111 1100+1 = 1111 1101 or FD.Now try read the data from SCON register.

Read SCON and write to accumulator A and BADDRESSHEX codeLabelInstructionComment9000MOV A,SCON A=?MOV B,AB=?Q. What is the location of the serial control register (SCON)?A. _______________________________________Change the SCON in above code to TMOD register. Single step the code and answer below question.Q. What is the value of TMOD register?A. ______________________________The SCON and TMOD are the example of registers that used to control the serial port and internal timer. We will learn on later how to use them.Q. Can you find the instruction MOV A,SCON or MOV A,TMOD in the 8051 instruction sheet? What is the addressing mode that used to access such registers?A. _______________________________________________________________

Using R7 for repeating codeADDRESSHEX codeLabelInstructionComment9000MOV R7,#0HEREDJNZ R7,HERECLR P1.7 Before pressing the STEP key, press REG. to select user register display for R4-7.Q. How many times the instruction DJNZ R7 will be repeated?A. _______________________________________________Q. What is the location of bit 7 of the PORT P1? When the LED (P1.7) will be turned ON?A. __________________________________________________________________

Adding 16-bit number using R0 (low byte), R1 (high byte) and DPL, DPH

R1 R0 +

DPH DPL

_________

ADDRESSHEX codeLabelInstructionComment9000MOV R0,#FFHMOV R1,#1FHMOV DPL,#1MOV DPH,#0MOV A,DPLADD A,R0Cy=?MOV R0,AMOV A,DPHADDC A,R1Cy=?MOV R1,AQ. What is the result of addition?A. R1=_______ R0 = _________Q. Change the value from 1FFF in R1, R0 and 0001 in DPH,DPL to the new two 16-bit numbers i.e. 2FFF + 9E78. A. compute by hand calculation (HEX)=____________2FFF0010 1111 1111 11119E78 + 1001 1110 0111 1000 +______________________The result by single stepping the code R1, R0(HEX) =________PAGE PAGE 11