Facebook
Google
GitHub
Linkedin
Is this code turning on the LEDs one by one with a timer between them??
Rich (BB code):
;Declare some new variables...according to the datasheet, user RAM starts at address 0x0C
W_TEMP EQU 0x0C ;Temp storage of wreg in interupt
STATUS_TEMP EQU 0x0D ;temp storage of STATUS reg in interupt
TEMP1 EQU 0x0E ;temp storage
TEMP2 EQU 0x0F ;temp storage
SECH EQU 0x10 ;second counter high byte
SECL EQU 0x11 ;second counter low byte
T0OVFLCNT EQU 0x12 ;timer0 overflow count
TMR0 EQU 0x01 ;timer0 reg loc is 01H
INTCON EQU 0x0B ;INTCON reg loc is 0BH
T0IF EQU 2 ;T0IF is bit 2 in the INTCOM reg
T0IE EQU 5 ;t0IE is bit 5 in the INTCOM reg
GIE EQU 7 ;GIE is bit 7 in the INTCOM reg
;Here, a macro will be declared so that in the code, the same instructions won't need to be typed over ;and over to complete
;this function. Instead, wherever SUB1616 is located in the code, when the code is compiled, all these instructions
;will be inserted in that spot of the code.
;This macro does A1:A2 - B1:B2, only to check whether or not A1:A2 is >= B1:B2
SUB1616 macro A1,A2,B1,B2
MOVF B2,0 ;get low byte of second word and in Wreg
SUBWF A2,0 ;subtract low byte of second word from low ;byte of first word
MOVF B1,0 ;get high byte of second word
BTFSS STATUS,CARRY ;check for positive result from sub
INCFSZ B1,0 ;if not, borrow from higj byte by adding on ;to high bute of secnd word
GOTO $ + 3 ;if no rollover in high byte increment, ;jump to three instructions ahead
BCF STATUS,CARRY ;if rollover in high byte increment, sub ;result is not positive
GOTO $ + 2 ;sub finsihed, jump two instructions ahead
SUBWF A1,0 ;sub high byte of second word from high ;byte of first word
endm
;An interrupt will be used, so the main code address and the interrupt code address must be declared
;According to the datasheet, main code goes at 0x0000, and interrupt code goes at 0x0004
ORG 0x0000
GOTO MAIN
ORG 0x0004
MOVWF W_TEMP ;save current wreg
MOVF STATUS,0
MOVWF STATUS_TEMP ;save current STATUS reg
INT_TMR0 BCF INTCON,T0IF ;clear the TMR0 overflow interupt flag
INCF T0OVFLCNT,1 ;increment timer0 overflow count
BTFSS T0OVFLCNT,4 ;check bit 4 of timer0 overflow count
GOTO INT_TMR0END ;if 64 overflows have not occurred, return ;from interupt
CLRF T0OVFLCNT ;reset overflow count
INCFSZ SECL,1 ;increment seconds, check for rollover
GOTO INT_TMR0END ;if no rollover, return from interrupt
INCF SECH,1 ;if rolover, increment second count high ;byte
GOTO INT_TMR0END ;return from interupt
INT_TMR0END MOVF STATUS_TEMP,0 ;retrieve copy of STATUS reg
MOVWF STATUS ;restore pre-interupt STATUS reg
SWAPF W_TEMP,1
SWAPF W_TEMP,0 ;restore pre-interupt Wreg
RETFIE
MAIN CLRF PORTB ;all LEDs off
CLRF STATUS ;initailize registers
CLRF W_TEMP
CLRF STATUS_TEMP
CLRF TEMP1
CLRF TEMP2
CLRF SECH
CLRF SECL
CLRF T0OVFLCNT
CLRF TMR0
CLRF INTCON
BSF STATUS,RP0 ; select REG bank1
CLRF TRISB ;set PORTB to outputs
MOVLW 0x07
MOVWF OPTREG ;assign prescaler to TMR0
BCF STATUS,RP0 ;select register bank 0
CLRF TMR0 ;reset timer0
BCF INTCON,T0IF ;clear timer0
BSF INTCON,T0IE ;enable timer0 interupt flag
BSF INTCON,GIE ;enable global interupts
BSF PORTB,0 ;turn on LED connected to PB0
BCF STATUS,CARRY ;clear CARRY
A MOVLW 0x00 ;set first timer compare at 2 seconds
MOVWF TEMP1 ;0 for high byte
MOVLW 0x02
MOVWF TEMP2 ;2 for low byte
BCF INTCON,GIE ;disable interupts
SUB1616 SECH,SECL,TEMP1,TEMP2 ;
BSF INTCON,GIE ;
BTFSS STATUS,CARRY ;check for positive result from sub
GOTO A ;
BCF PORTB,0 ;clear PortB
B MOVLW 0x00 ;set first timer compare at 2 seconds
MOVWF TEMP1 ;0 for high byte
MOVLW 0x3E
MOVWF TEMP2 ;62 for low byte
BCF INTCON,GIE ;disable interupts
SUB1616 SECH,SECL,TEMP1,TEMP2 ;
BSF INTCON,GIE ;enable interupts
BTFSS STATUS,CARRY ;check for sub result >= 0
GOTO B ;if not, stay in loop
BSF PORTB,1 ;if >=0, turn on LED connected to PB1
C MOVLW 0x00 ;set third timer compare at 122 seconds ;(cumulative timer)
MOVWF TEMP1 ;0 for high byte
MOVLW 0x7A
MOVWF TEMP2 ;122 for low byte
BCF INTCON,GIE ;disable interupts
SUB1616 SECH,SECL,TEMP1,TEMP2 ;
BSF INTCON,GIE ;enable interupts
BTFSS STATUS,CARRY ;check for sub result >=0
GOTO C ;if not rollover in high byte increment to ;three instructions ahead
BSF PORTB,2 ;if >=0, turn on LED connected to PB2
D MOVLW 0x00 ;set second timer compare at 182 seconds
MOVWF TEMP1 ;0 for high byte
MOVLW 0xB6
MOVWF TEMP2 ;182 for low byte
BCF INTCON,GIE ;disable interupts
SUB1616 SECH,SECL,TEMP1,TEMP2 ;
BSF INTCON,GIE ;enable interupts
BTFSS STATUS,CARRY ;check for sub result >=0
GOTO D ;if not, stay in loop
BSF PORTB,3 ;if >=0, turn on LED connected to PB3
E MOVLW 0x01 ;set second timer compare at 302 seconds
MOVWF TEMP1 ;16-bit equivelant for 302 is 0x12E
MOVLW 0x2E
MOVWF TEMP2
BCF INTCON,GIE ;disable interupts
SUB1616 SECH,SECL,TEMP1,TEMP2 ;
BSF INTCON,GIE ;enable interupts
BTFSS STATUS,CARRY ;check for sub result >=0
GOTO E ;if not, stay in loop
BSF PORTB,4 ;if >=0, turn on LED connected to PB4
BCF INTCON,GIE ;disable interupts
BCF INTCON,T0IE ;disable timer0
CLRF TMR0 ;reset timer0
BCF INTCON,T0IF ;clear timer0 interrupt flag
GOTO E ;loop back to beginning
END
