PIC18F1230 MICROCHIP [Microchip Technology], PIC18F1230 Datasheet - Page 111

• Manufacturer Part Number: PIC18F1230
• Description: 18/20/28-Pin, Enhanced Flash Microcontrollers with nanoWatt Technology, High-Performance PWM and A/D
• Manufacturer: MICROCHIP [Microchip Technology]

EXAMPLE 12-1:
TABLE 12-2:
© 2006 Microchip Technology Inc.
INTCON
PIR1
PIE1
IPR1
TMR1L
TMR1H
T1CON
Legend: x = unknown, u = unchanged, — = unimplemented, read as ‘0’.
RTCinit
RTCisr
Name
Shaded cells are not used by the Timer1 module.
Timer1 Register Low Byte
Timer1 Register High Byte
GIE/GIEH
RD16
MOVLW
MOVWF
CLRF
MOVLW
MOVWF
CLRF
CLRF
MOVLW
MOVWF
BSF
RETURN
BSF
BCF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
MOVLW
MOVWF
RETURN
Bit 7
—
—
—
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
PEIE/GIEL
0x80
TMR1H
TMR1L
b’00001111’
T1OSC
secs
mins
.12
hours
PIE1, TMR1IE
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
secs
secs
mins, F
.59
mins
mins
hours, F
.23
hours
.01
hours
T1RUN
ADIF
ADIE
ADIP
Bit 6
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
TMR0IE
RCIF
RCIE
RCIP
Bit 5
Advance Information
INT0IE
TXIE
TXIP
Bit 4
TXIF
; 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
CMP2IF
CMP2IE
CMP2IP
RBIE
Bit 3
PIC18F1230/1330
CMP1IF
CMP1IE
CMP1IP
TMR0IF
Bit 2
CMP0IE TMR1IE
CMP0IP TMR1IP
CMP0IF
INT0IF
Bit 1
TMR1IF
RBIF
Bit 0
DS39758B-page 109
Values on
Reset
page
41
43
43
43
42
42
42