PIC18F4550-I/P Microchip Technology Inc., PIC18F4550-I/P Datasheet - Page 135

• Manufacturer Part Number: PIC18F4550-I/P
• Description: 40 PIN, 32 KB FLASH, 2048 RAM, FS-USB 2.0
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4550-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 34
• Interface: I2C/SPI/UART/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

EXAMPLE 12-1:
TABLE 12-2:
© 2006 Microchip Technology Inc.
INTCON
PIR1
PIE1
IPR1
TMR1L
TMR1H
T1CON
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.
Note 1:
RTCinit
RTCisr
Name
These bits are unimplemented on 28-pin devices; always maintain these bits clear.
Timer1 Register Low Byte
TImer1 Register High Byte
GIE/GIEH PEIE/GIEL
SPPIE
SPPIP
SPPIF
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
RD16
Bit 7
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
(1)
(1)
(1)
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
80h
TMR1H
TMR1L
b’00001111’
T1OSC
secs
mins
d’12’
hours
PIE1, TMR1IE
TMR1H, 7
PIR1, TMR1IF
secs, F
d’59’
secs
secs
mins, F
d’59’
mins
mins
hours, F
d’23’
hours
d’01’
hours
T1RUN
ADIE
ADIP
ADIF
Bit 6
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
TMR0IE
RCIE
RCIP
RCIF
Bit 5
PIC18F2455/2550/4455/4550
; 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
INT0IE
Preliminary
TXIE
TXIP
Bit 4
TXIF
SSPIF
SSPIE
SSPIP
RBIE
Bit 3
TMR0IF
CCP1IF
CCP1IE
CCP1IP
Bit 2
TMR1CS
TMR2IF
TMR2IE
TMR2IP
INT0IF
Bit 1
TMR1ON
TMR1IF
TMR1IE
TMR1IP
RBIF
DS39632C-page 133
Bit 0
on page
Values
Reset
51
54
54
54
52
52
52