Respected Russell Sir,

Here are the 2 subroutines again ... pl have a look !!!

SUBROUTINE 1

DELAY_MS:
MOV R7,#00H

LOOPA:
INC R7 ; CYCLES = 1
MOV A,R7 ; CYCLES = 1
CJNE A,#0FFH,LOOPA ; CYCLES = 2
RET ; CYCLES = 2

****************************************************************
SUBROUTINE 2

DELAY_HS:
MOV R6,#00H ; CYCLES = 1
MOV R5,#002H ; CYCLES = 1

LOOPB:
INC R6 ; CYCLES = 1
ACALL DELAY_MS ; CYCLES = 2
MOV A,R6 ; CYCLES = 1
JNZ LOOPB ; CYCLES = 2
DEC R5 ; CYCLES = 1
MOV A,R5 ; CYCLES = 1
JNZ LOOPB ; CYCLES = 2
RET ; CYCLES = 2

================================================================

Before the two subroutines there are some statements which I am not writing here ... so they also takes some CYCLES ...

I'll try to make you understand now ...

Sir in the 1st SUBRT the total cycles is 5 excluding RET ie 2 more ...

*> It is calculating 256 values ...
*> If only 256 cycles is considered then the time delay is
256 microseconds ... ie 1 cycles = 1 microseconds .
*> But the delay generated by SUBRTN 1 is 1 MILLISECONDS
ie. 1027 cycles ... ie 1027 microseconds

Now SUBROTN 2 is also making delay ... but it is making .5 seconds delay ...

*> SUBRTN 2 run for two values of R5 -> 2 and 1 ...
*> Depending on the value of R5, the value of R6 is incremented
two times from 0 to 255 ie. 512 times ... so 512 cycles ...
*> But besdies the vbalue of R6 incremented ... the other
cycles like :
.................................................
LOOPB:
INC R6 ; CYCLES = 1
ACALL DELAY_MS ; CYCLES = 2
MOV A,R6 ; CYCLES = 1
JNZ LOOPB ; CYCLES = 2
...............................................
so around 6 cycles each time should be considered
when calling to subroutine 1 ...

*> If we take this value then it is coming 3080 CYCLES and not
512 cycles for two values of R5 ...

================================================================

Now if take the case ...

3080 * 1027 = 3163160 ... which is 3.16 seconds

and if we take only 512 cycles of subrtn 2 then ...

512 * 1027 = 525824 ... which is .5 seconds

Now I am sure you mit get my probs ...

Waiting for your kind guidance and reply ...

Regards
Arvind Shrivastava ...