;-----------------------------------------------------------------------; ; BINCLOCK.ASM A clock that displays in bcd numbers ; ;-----------------------------------------------------------------------; LIST P=16F87 ; tells which processor is used INCLUDE "p16f87.inc" ; defines various registers etc. Look it over. ERRORLEVEL -224 ; supress annoying message because of tris ;Program Configuration Register 1 __CONFIG _CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_ON & _BODEN_ON & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _LP_OSC ;Program Configuration Register 2 __CONFIG _CONFIG2, _IESO_OFF & _FCMEN_OFF ;__CONFIG _WDT_OFF & _PWRTE_ON & _XT_OSC ; configuration switches EREDETI CONFIG CBLOCK 0CH sec ; seconds digit sec10 ; 10's of second digit mins ; minutes digit min10 ; 10's of minutes digit hr ; hours digit hr10 ; 10's of hours digit w_temp ; holds W during interrupt status_temp ; holds STATUS during interrupt fsr_temp ; holds FSR during interrupt button ; holds mask for pushbuttons ENDC ;-----------------------------------------------------------------------; ; Here are some DEFINEs which give 'names' to pushbutton port bits ; ;-----------------------------------------------------------------------; #DEFINE SETPB PORTB, 4 #DEFINE SELECTPB PORTB, 5 #DEFINE SHOWPB PORTB, 6 ORG 0 ; start at location 0 goto main ; jump over to main routine ORG 4 goto isr ; jump to interrupt routine ;-----------------------------------------------------------------------; ; High limit + 1 of digits at position W ; ;-----------------------------------------------------------------------; sethi: addwf PCL, f dt H'A',H'6',H'A',H'6',H'A',H'3' ;-----------------------------------------------------------------------; ; Delay routines ; ;-----------------------------------------------------------------------; msec250: ; enter here to delay for 250 milliseconds movlw D'250' nmsec: ; delay for # msec in W on entry nop ; each nop is 0.122 milliseconds nop nop ; each total loop is 8 X 0.122 = 0.976 msec nop addlw H'FF' ; same as subtracting 1 from W btfss STATUS, Z ; skip if result is zero goto nmsec ; this is 2 X 0.122 msec return ; back to calling point ;-----------------------------------------------------------------------; ; Delay for one second ; ;-----------------------------------------------------------------------; onesecond: ; a subroutine that delays for 1 seconds call msec250 call msec250 call msec250 call msec250 return ;-----------------------------------------------------------------------; ; Put value in W on LEDs for 1 second ; ;-----------------------------------------------------------------------; sendnbr: movwf PORTB ; light LEDs call onesecond ; wait 1 second clrf PORTB ; clear the LEDs movlw D'100' ; pause for 0.1 sec call nmsec return ;-----------------------------------------------------------------------; ; Send the current time out LEDs ; ;-----------------------------------------------------------------------; disptime: movf hr10, W call sendnbr movf hr, W call sendnbr movf min10, W call sendnbr movf mins, W call sendnbr return ;-----------------------------------------------------------------------; ; Wait until selected button is released ; ;-----------------------------------------------------------------------; waitup6: ; wait for show pushbutton up movlw B'01000000' ; RB6 mask movwf button goto wait waitup5: ; wait for select pushbutton up movlw B'00100000' ; RB5 mask movwf button goto wait waitup4: ; wait for set pushbutton up movlw B'00010000' ; RB4 mask movwf button wait: movf button, W ; mask into W andwf PORTB, W btfsc STATUS, Z ; skip if not zero (released) goto wait movlw D'10' call nmsec ; wait 10 msec for debounce movf button, W ; check for release again andwf PORTB, W btfsc STATUS, Z ; skip if selected button released goto wait return ; yes, finished ;-----------------------------------------------------------------------; ; Initilization Subroutine ; ;-----------------------------------------------------------------------; init: movlw B'0000000' ; all outputs port A tris PORTA movlw B'01110000' ; RB4 - RB6 inputs, others outputs tris PORTB ; on port B movlw H'0' ; all low (off) movlw PORTB movlw B'00000100' ; pull-ups enabled ; prescaler assigned to TMR0 ; prescaler set to 1:32 ; rolls over each second option movlw 0 movwf hr10 movlw H'9' ; initialize hrs, mins and secs movwf hr ; Do this before interrupts are movlw H'5' ; turned on because isr also acts movwf min10 ; on these registers movlw H'0' movwf mins movwf sec10 movwf sec movlw B'10100000' ; GIE & T0IE set, cleared movwf INTCON return ;-----------------------------------------------------------------------; ; Interrupt routine, increments time by one second (BCD) ; ;-----------------------------------------------------------------------; isr: movwf w_temp ; save W swapf STATUS,W ; save status movwf status_temp ; without changing flags swapf FSR,W ; save FSR movwf fsr_temp ; without changing flags movlw sec ; point at sec register movwf FSR newdigit: incf INDF, f ; current digit up one movlw sec ; get difference between sec and FSR subwf FSR, W call sethi ; use to get high limit + 1 subwf INDF, W ; reached that number yet? btfss STATUS, Z ; skip over if yes goto restore ; else exit isr clrf INDF ; set current digit to 0 incf FSR, f ; point at next digit btfss hr10, 1 ; has hr10 reached 2? goto newdigit ; no, increment the next digit btfss hr, 2 ; has hr reached 4? goto newdigit ; no clrf hr ; yes, set hour to 00 clrf hr10 ; and hour 10 restore: swapf status_temp,W ; get original status back movwf STATUS ; into status register swapf fsr_temp,W ; get original fsr back movwf FSR ; into status register swapf w_temp,f ; old no flags trick again swapf w_temp,W ; to restore W bcf INTCON,TMR0IF ; clear the TMR0 interrupt flag retfie ; finished reset GIE ;-----------------------------------------------------------------------; ; Increment and display digit pointed to by FSR ; ;-----------------------------------------------------------------------; updigit: incf INDF, f ; selected digit up one movlw mins ; set up to subtract mins address subwf FSR, W ; from address of current digit call sethi ; get maximum of digit + 1 into W subwf INDF, W ; is it = to current digit value? btfsc STATUS, Z ; gives zero if yes, skip if no clrf INDF ; reset value of digit to zero movf INDF, W ; get current value and .. movwf PORTB ; display it call onesecond ; pause for 1 second return ;-----------------------------------------------------------------------; ; increment selected digit until select pressed ; ;-----------------------------------------------------------------------; setdigit: movwf PORTB btfss SETPB ; set pressed? call updigit ; yes btfsc SELECTPB ; check if select pressed goto $ -3 ; repeat till select pressed again call waitup5 ; make sure select released incf FSR, f return ;-----------------------------------------------------------------------; ; Select and increment digits ; ;-----------------------------------------------------------------------; select: bcf INTCON, GIE ; no interrupts while setting time movlw mins ; point at minutes register movwf FSR call waitup5 ; wait on select pushbutton up movlw B'00000001' ; light right LED (mins) call setdigit movlw B'00000010' ; light min10 LED call setdigit movlw B'00000100' ; light hr LED call setdigit movlw B'00001000' ; hr10 LED on call setdigit clrf PORTB ; clear LEDs bsf INTCON, GIE ; enable interrupts again return ;-----------------------------------------------------------------------; ; The main routine ; ;-----------------------------------------------------------------------; main: call init ; set up initial conditions loop: btfss SHOWPB ; check for show pushbutton call disptime ; display the time btfss SELECTPB ; check for select call select goto loop ; do forever end