DELAY FUNCTION IS NOT RETURNED

loop1: JNB  TF0, $

What happens with this one-line loop depending on TF0 contents? Might it affect your 1-second delay time?

Thanks for your reply.
I checked my program again, and I realized that i forgot to config Timer 0 in 16 bit mode. (MOV TMOD, #00000001b) in main function. And I run debug again, but the program still doesn't work.
I expose here two modules (delay.a and main.a) again.
main.a

extrn code (delay_s)
extrn data      (delay_s_i)
org 0000h
jmp     start
org 0050h
start:
mov sp, #7fh
mov     TMOD, #00000001b ; Timer 0 - 16bit mode
main:
clr p2.0
mov     delay_s_i, #1
call delay_s
setb    p2.0
mov     delay_s_i, #1
call delay_s
jmp main
end

delay_s.a

;===========================================================================
;Description:
;               - delay for approximately 1 s
;               - in: delay_s_i
;               - out: non


                                        PUBLIC                  delay_s_i, delay_s
;=====================================================
?DT?delay                       SEGMENT                 DATA
RSEG                    ?DT?delay
delay_s_i:      DS      1
;=====================================================
?PR?delay                       SEGMENT                 CODE
RSEG                    ?PR?delay
delay_s:
MOV                             A, delay_s_i
MOV                             B, #14
MUL                             AB
MOV                             delay_s_i, A
MOV                             A, #0
SETB                    TR0
loop1:                          JNB                             TF0, $
CLR                             TF0
DEC                             delay_s_i
CJNE                    A, delay_s_i, loop1
RET
END

Running debug again, when encounter the

 call delay_s

in main function, there's an error in debug window, it's "error 65: access violation at I:0x81: no 'write' permission.; it means the address of next instruction was not pushed into stack and I think this causes the problem. When encounter

 RET

, there's no value popped out of stack (and 0 value popped out instead), and the program restart at 0000h, not be returned to where it was called.

Thanks and wait for your answers.

there's an error in debug window
is it the Keil simulator
is it the SILabs emulator
is it the ultramon monitor
is it the acme whatschamacallit
is it ....

nobody can help you if tou keep secrets

Erik

in main function, there's an error in debug window
does it even compile without a prototype? or are you one of those that ignore warnings?

Erik

does it even compile without a prototype?

Ahem, Erik, are you aware that we're talking about a piece of assembly code here, as in: code to which the concept of a prototype declaration doesn't even apply? Nor that of "compiling", for that matter?

Ahem, Erik
Sunday morning sleepies. OOPS

still need to know what "the debugger" is

Erik

Sorry for not supplying enough information.
I'm just beginner using Keil C, and i don't know much. I don't mean to keep secret.
I'm using Keil Simulator.

Erik;
You need to cut some slack for OPS that use the Keil terms for their simulator. Keil calls it a "Debugger" in all their sales documents and in their operation manuals.
Yes, it is a simulator but connected to a target board it can rightly be called a "Debugger".
So, let the OPS call it a debugger. It's not difficult to discern what they mean.
Bradford

It's not difficult to discern what they mean.
... where 'discerning' has led a thread astray

Erik

Hello.
I solved my problem.
When initializing the stack, i used "MOV SP, #7F", so, I can't use "push" instruction because the address above 7F is SFRS, not for stack.
Thanks

today, only a few derivatives will not 'run' the stack to 0xff you did not mention which derivative you were using.

Most beginners makes omissions in their first visit to the forum, no 'blame', just remember.

Erik