Statement:Write a program for displaying BCD down counter. Counter should count numbers from 99 to 00 and it should increment after every 1 sec. Assume operating frequency of 8085 equal to 3MHz. Display routine is available.
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Source program 1:
- LXI SP, 27FFH : Initialize stack pointer
- MVI C, 99H : Initialize counter = 99
- BACK:CALL Display : Call display subroutine
- CALL Delay : Call delay subroutine
- ADI 99H : See Addition below
- DAA : Adjust for decimal
- CPI 99H : Compare with last count
- JNZ BACK :If no, repeat
- HLT
 Source Program 2: - LXI SP, 27FFH : Initialize stack pointer
- MVI C, 99H : Initialize counter = 99
- BACK: CALL Display : Call display subroutine
- CALL Delay : Call delay subroutine
- MOV A, C : Get count
- ANI 0FH : Check for lower nibble
- JNZ SKIP : If it is not 0FH go to skip
- MOV A,C : Else get the count
- SBI ,06 : Subtract 06
- MOV C,A : Store the count
- DCR C : Decrement count
- CPI 99H : Check it for last count
- JNZ BACK : If not, repeat
- HLT : Stop
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Flowchart for Program 
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