PIC18LF2682-I/P View Datasheet(PDF) - Microchip Technology
Part Name
Description
Manufacturer
PIC18LF2682-I/P
Microchip Technology
PIC18LF2682-I/P Datasheet PDF : 484 Pages
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PIC18F2682/2685/4682/4685
EXAMPLE 12-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
RTCinit
RTCisr
MOVLW
MOVWF
CLRF
MOVLW
MOVWF
CLRF
CLRF
MOVLW
MOVWF
BSF
RETURN
80h
TMR1H
TMR1L
b’00001111’
T1OSC
secs
mins
.12
hours
PIE1, TMR1IE
BSF
BCF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
MOVLW
MOVWF
RETURN
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
secs
secs
mins, F
.59
mins
mins
hours, F
.23
hours
.01
hours
; Preload TMR1 register pair
; for 1 second overflow
; Configure for external clock,
; Asynchronous operation, external oscillator
; Initialize timekeeping registers
;
; Enable Timer1 interrupt
; Preload for 1 sec overflow
; Clear interrupt flag
; Increment seconds
; 60 seconds elapsed?
; No, done
; Clear seconds
; Increment minutes
; 60 minutes elapsed?
; No, done
; clear minutes
; Increment hours
; 24 hours elapsed?
; No, done
; Reset hours to 1
; Done
TABLE 12-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on page
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE
RBIE TMR0IF INT0IF
RBIF
49
PIR1
PSPIF(1) ADIF
RCIF
TXIF
SSPIF CCP1IF TMR2IF TMR1IF
52
PIE1
PSPIE(1) ADIE
RCIE
TXIE
SSPIE CCP1IE TMR2IE TMR1IE
52
IPR1
PSPIP(1) ADIP
RCIP
TXIP
SSPIP CCP1IP TMR2IP TMR1IP
52
TMR1L Timer1 Register Low Byte
50
TMR1H TImer1 Register High Byte
50
T1CON
RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 50
Legend: x = unknown, u = unchanged, — = unimplemented, read as ‘0’.
Shaded cells are not used by the Timer1 module.
Note 1: These bits are unimplemented on PIC18F2682/2685 devices; always maintain these bits clear.
© 2007 Microchip Technology Inc.
Preliminary
DS39761B-page 155
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