Holtek HT-IDE, User Manual

Page: 225 / 258

mov tmr0h,a ;(high byte)
set tmr0c.4 ;start timer0
loop: ;(3) ;
mov a,0 ;zero table index
mov tblp,a ;
mov a,minl ;load display data
mov disp,a ;(’low’ minute)
call show_clock ;show displaying up (4th 7-segment)
inc tblp ;
mov a,minh ;load displaying data
mov disp,a ;(’high’ minute)
call show_clock ;show displaying up (3rd 7-segment)
inc tblp ;
mov a,hourl ;load displaying data
mov disp,a ;(’low’ hour)
call show_clock ;show displaying up (2nd 7-segment)
inc tblp ;
mov a,hourh ;load displaying data
mov disp,a ;(’high’ hour)
call show_clock ;show displaying up (1st 7-segment)
jmp loop ;repeat from loop
;------------------------------------------------------------
cal_number proc ;
inc minl ;minl+1
mov a,minl ;
sub a,0ah ;
sz acc ;if over 10 minutes?
ret ;no. return
clr minl ;yes. minl=0
inc minh ; minh+1
mov a,minh ;
sub a,06h ;
sz acc ;if over 60 minutes?
ret ;no. return
clr minh ;yes. minh=0
mov a,hourh ;
sub a,02h ;
sz acc ;if over 20 hours?
jmp h_20 ;no. goto h_20
inc hourl ;yes. hourl+1
mov a,hourl ;
sub a,04h ;
sz acc ;if over 24 hours?
ret ;no. return
clr hourl ;yes. hourl=0
clr hourh ; hourh=0
ret ;return
h_20: ;
inc hourl ;hour1+1
Chapter 16 Interrupt and timer applications
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