10/12

PWM GENERATION WITH THE ST62 16-BIT AUTO-RELOAD TIMER

inc

x

ld

a,(x)

ld

Lsb_inc1,a

inc

x

ld

a,(x)

ld

Msb_inc2,a

; Second tone

inc

x

ld

a,(x)

ld

Lsb_inc2,a

ldi

drwr,20h

; Rom window with sinus

ret

;***********************END OF DTMF GENERATION************************

;**************************************************************************

;***************************** interrupt routine **************************

;*** timer interrupt ***

it_timer

jrr

0,WaitTone,Break

ld

a,NToSend

jrr

3,NToSend,TelNotFinish

TelLoop:

jrs

1,NToSend,TelLoop; infinit loop for this application note

; after dialing 10 numbers

TelNotFinish:

addi

a,Tel_Num

ld

x,a

ld

a,(x)

call

InitTone

; Initialize the increment tone

ldi

tcr,0ffh

; Reload the counter for 96ms

inc

NToSend

JP

end_tim

Break:

ldi

Lsb_inc1,0

; All data to 0 for no sound.

ldi

Msb_inc1,0

; For other applications, the time break

ldi

Lsb_inc2,0

; could be used for process instead of

ldi

Msb_inc2,0

; calculate nothing

ldi

Lsb_ton1,0

ldi

Msb_ton1,0

ldi

Lsb_ton2,0

ldi

Msb_ton2,0

ldi

tcr,06ah

; Reload the counter for 40ms

end_tim

inc

WaitTone

res

tmz,tscr

; Restart the timer.

reti