Make a Digital Clock in 8085 programming | Programming Techniques:
8085 is a assembly level programming. It uses a lot of mnemonics to write a code. To understand a lot of mnemonics is a negative part of any assembly level programming. The following code designs a digital clock with approximately 1 second delay (it depends upon your kits frequency). The delay is calculated by multiplying total T-states an time required for each T-states. It is a 12 hours clock and resets its time after 12 hours.
Source Code
MVI A,80H
OUT 43
START: MVI D,00H
NEXTHOUR:
MVI C,00H
NEXTMINUTE:
MVI E,00H
NEXTSECOND:
PUSH B
CALL CALLING
POP B
INR E
MOV A,E
OUT 40
CPI 3CH
JNZ NEXTSECOND
INR C
MOV A,C
OUT 41
CPI 3CH
JNZ NEXTMINUTE
INR D
MOV A,D
OUT 42
CPI CH
JNZ NEXTHOUR
JMP START
CALLING:
LXI B,FFFFH
DELAY:
DCX B
MOV A,C
ORA B
NOP
NOP
RZ
JMP DELAY
The two lines of code : MVI A, 80 and OUT 43 is used to initialize output port. It varies on kit to kit. So see your manufacturer's specifications for this.
8085 is a assembly level programming. It uses a lot of mnemonics to write a code. To understand a lot of mnemonics is a negative part of any assembly level programming. The following code designs a digital clock with approximately 1 second delay (it depends upon your kits frequency). The delay is calculated by multiplying total T-states an time required for each T-states. It is a 12 hours clock and resets its time after 12 hours.
Source Code
MVI A,80H
OUT 43
START: MVI D,00H
NEXTHOUR:
MVI C,00H
NEXTMINUTE:
MVI E,00H
NEXTSECOND:
PUSH B
CALL CALLING
POP B
INR E
MOV A,E
OUT 40
CPI 3CH
JNZ NEXTSECOND
INR C
MOV A,C
OUT 41
CPI 3CH
JNZ NEXTMINUTE
INR D
MOV A,D
OUT 42
CPI CH
JNZ NEXTHOUR
JMP START
CALLING:
LXI B,FFFFH
DELAY:
DCX B
MOV A,C
ORA B
NOP
NOP
RZ
JMP DELAY
The two lines of code : MVI A, 80 and OUT 43 is used to initialize output port. It varies on kit to kit. So see your manufacturer's specifications for this.
