Program to test RAM

Statement: To test RAM by writing '1' and reading it back and later writing '0' (zero) and reading it back. RAM addresses to be checked are 40FFH to 40FFH. In case of any error, it is indicated by writing 01H at port 10H.

Source program :

• LXI H, 4000H : Initialize memory pointer
• BACK: MVI M, FFH : Writing '1' into RAM
• MOV A, M : Reading data from RAM
• CPI FFH : Check for ERROR
• JNZ ERROR : If yes go to ERROR
• INX H : Increment memory pointer
• MOV A, H
• CPI SOH : Check for last check
• JNZ BACK : If not last, repeat
• LXI H, 4000H : Initialize memory pointer
• BACKl: MVI M, OOH : Writing '0' into RAM
• MOV A, M : Reading data from RAM
• CPI OOH : Check for ERROR
• INX H : Increment memory pointer
• MOV A, H
• CPI SOH : Check for last check
• JNZ BACKl : If not last, repeat
• HLT : Stop Execution