Copy the content of memory location from one place to other (Block copy) in ARM LPC2148

AIM: Copy the content of memory location from one place to other.

THEORY:

This operation is carried out by copying content of 5 memory location. Source memory address is 0x01 and destination memory address is 0x21 by using LDR and STR instructions.

PORCEDURE:

For creating project, we need to take following steps.

1) Create new project

2) Algorithm

3) Simulation of Algorithm

These three steps are involved in procedure.

1) Create new project

1.   Select a new project and give particular name to that project. e.g Block_copy

2.   Select chip NXP (founded by Philips) LPC2148.

3.   For assembly language don’t add startup file.

4.   Select a new editor file, write logic in that file and save it by using .asm extension in assembly language.

2) Algorithm

Algorithm consists of following steps.

Block copy:

1.   Initialize source memory pointer 0x01 to register R0.

2.   Initialize destination memory pointer 0x21 to register R1.

3.   Initialize counter to 4.

4.   By using LDR instruction copy content from 1^st memory location and increment address register by one. Post index addressing mode is used here.

5.   By using STR instruction store content to destination memory pointer and increment address register by one. Post index addressing mode is used here.

6.   Decrement counter by one and do this process till it reaches to zero.

3) Simulation of Algorithms

It consists of following steps.

1.   After writing program just build it.

2.   If there are any errors, they will be due to some mistake in typing the program. To locate the error, double click on the first error. Check for the error and remove it. Repeat this till all errors are gone.

3.   Now it’s time to debug. Click on the debug tab and debug program. Check the contents of the registers in assembly language programming and contents of the variables in embedded c programming.

OBSERVATIONS:

Content of the memory locations after copying:

1.   1^st memory location : …………………..

2.   2^nd memory location : …………………..

3.   3^rd memory location : …………………..

4.   4^th memory location : …………………..

5.   5^th memory location : …………………..

Copy the content of memory location from one place to other in Assembly.

AREA BLOCK_COPY, CODE, READONLY

ENTRY

START

            MOV R0,#04   ; Counter initialization

            MOV R1,#0X01   ; Source address

            MOV R2,#0X21   ; Destination Address

            BL DONE

            SWI 0X11

DONE

            LDR R3,[R1],#1  ; Postindexing mode

            STR R3,[R2],#1   ;Postindexing mode

            SUB R0,R0,#1

            CMP R0,#0

            BNE DONE

            MOV PC,LR

END