Sir,
Following are few questions that i like to ask in order to understand the working or links in your code so that i understand this instead of copy pasting.

can you please just write comments in front of your code lines so that i can understand the working.


The program for two bits will be like;

; consider that we are processing bit P2.0


SCAN_LOOP:
MOV R7,#00 ; Bit register
NEXT_BIT:
CALL PROCESS_BIT ;1st bit 0 is checked as R7 has 0
INC R7
CJNE R7,#1,NEXT_BIT ;considering only p2.0 to p2.1



PROCESS_BIT:
MOV DPTR,#BITS_LOOKUP
MOV A,R7

; Now A has value of R7 which at this stage is 0

ADD A,R7

;R7 is added and A has 00000000

Now what is happening here i have no idea, can you please explain why these steps are taken;

ADD A,DPL
MOV DPL,A
JNC PROCESS_BIT_0 ; why specially this step.
INC DPH


And please explain what is happening under the labels of,

PROCESS_BIT_0:
PROCESS_BIT_1:
PROCESS_BIT_R
PROCESS_BIT_L
PROCESS_BIT_H:

Now in the following i don;t understand how two type of data representing High and Low state will go to P1.

if Bit 0:
at start no data go to P1 if the bit HIGH
as soon as it gets
Low:- 00000001B data should go to P1
and after that as soon as 5 second reached or bit show high :- 00000000B goes to P1.

it may be happening in the following but i did not get it how it is happening?

; structure for process bit 0:
BIT0_DESCRIPTOR:
DB 00000001b
DB BIT0_TIMER
DB 0xA0,0xB0,0xC0

; structure for process bit 1:
BIT1_DESCRIPTOR:
DB 00000010b
DB BIT1_TIMER
DB 0xA1,0xB1,0xC1

BITS_LOOKUP:
DW BIT0_DESCRIPTOR
DW BIT1_DESCRIPTOR