;=======3x595.ASM================================11/02/07== list p=16f628A #include errorlevel -302 __CONFIG _CP_OFF & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF & _WDT_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT ;------------------------------------------------------------ ;------------------------------------------------------------ ; bit equates BINC equ 0 ;increase button BDEC equ 1 ;decrease button RBPU equ 7 ;RB PU enable bit ;------------------------------------------------------------ ; program variable cblock 0x20 cntr_lo cntr_mi cntr_hi temp ncount mcount sr_tmp sr_sr endc ;------------------------------------------------------------ ;------------------------------------------------------------ org 0x00 goto start org 0x04 ; org 0x05 start bsf STATUS,RP0 ;switch to bank 1 movlw b'11000111' ;inputs/outputs movwf TRISB bcf OPTION_REG,RBPU ;RB PU enable bcf STATUS,RP0 ;switch back to bank 0 movlw 0x07 ; movwf CMCON ;comparators off bcf STATUS,RP0 ;bank 0 clrf cntr_lo clrf cntr_mi clrf cntr_hi call outchg ;write out ;------------------------------------------------------------ repeat call pressck ;look for incr/decr button press movlw 0x80 ;delay 100 milliseconds movwf mcount loadn movlw 0xff movwf ncount decn decfsz ncount,f ;decrement N goto decn ;again decfsz mcount,f ;decrement M goto loadn ;again goto repeat ;------------------------------------------------------------ pressck btfss PORTB,BDEC ;decrease button pressed? call deccntr ;yes, decrement cntrs btfss PORTB,BINC ;increase button pressed? call inccntr ;yes, increment cntrs return ;------------------------------------------------------------ inccntr movf cntr_lo,w ;test for maximum sublw 0xff btfss STATUS,Z goto do_i ;not at maximum movf cntr_mi,w sublw 0xff ;compare btfss STATUS,Z goto do_i ;not at maximum movf cntr_hi,w ;test for maximum sublw 0xff btfss STATUS,Z goto do_i ;not at maximum goto inc ;at maximum do_i incf cntr_lo,f ;increment btfss STATUS,Z goto inc incf cntr_mi,f btfss STATUS,Z goto inc incf cntr_hi,f goto inc incf cntr_hi,f inc call outchg ;write out return ;press check done ;------------------------------------------------------------ deccntr movf cntr_lo,w ;test for minimum sublw 0x00 btfss STATUS,Z goto do_d ;not at minimum movf cntr_mi,w sublw 0x00 ;compare btfss STATUS,Z goto do_d ;not at minimum movf cntr_hi,w ;test for minimum sublw 0x00 btfss STATUS,Z goto do_d ;not at minimum goto dec ;at minimum do_d decf cntr_lo,f ;decrement movf cntr_lo,w sublw 0xff btfss STATUS,Z goto dec decf cntr_mi,f ;decrement movf cntr_mi,w sublw 0xff btfss STATUS,Z goto dec decf cntr_hi,f ;decrement dec call outchg ;write out return ;press check done ;------------------------------------------------------------ outchg movfw cntr_hi call set_leds ;write out bits <16:23> movfw cntr_mi call set_leds ;write out bits <8:15> movfw cntr_lo call set_leds ;write out bits <0:7> return ;------------------------------------------------------------ include "595.INC" ; ; end ;------------------------------------------------------------ ; memory unprotected ; watchdog timer disabled (default is enabled) ; INT_OSC (using 4 MHz osc for test) INT ; power-up timer on ; brown-out detect on ;============================================================