PIC18F8520-I/PT Microchip Technology Inc., PIC18F8520-I/PT Datasheet - Page 141

• Manufacturer Part Number: PIC18F8520-I/PT
• Description: 80 PIN, 32 KB FLASH, 2048 RAM, 68 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F8520-I/PT

• A/d Inputs: 16-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 1024 Bytes
• Input Output: 68
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 80-pin TQFP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 40 MHz
• Timers: 2-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part

EXAMPLE 12-1:
TABLE 12-2:
 2004 Microchip Technology Inc.
INTCON
PIR1
PIE1
IPR1
TMR1L
TMR1H
T1CON
Legend:
RTCinit
RTCisr
Name
Holding Register for the Least Significant Byte of the 16-bit TMR1 Register
Holding Register for the Most Significant Byte of the 16-bit TMR1 Register
GIE/GIEH PEIE/GIEL
x = unknown, u = unchanged, – = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.
PSPIF
PSPIE
PSPIP
RD16
Bit 7
MOVLW
MOVWF
CLRF
MOVLW
MOVWF
CLRF
CLRF
MOVLW
MOVWF
BSF
RETURN
BSF
BCF
INCF
MOVLW
CPFSGT secs
RETURN
CLRF
INCF
MOVLW
CPFSGT mins
RETURN
CLRF
INCF
MOVLW
CPFSGT hours
RETURN
MOVLW
MOVWF
RETURN
PIC18F6520/8520/6620/8620/6720/8720
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
0x80
TMR1H
TMR1L
b’00001111’
T1OSC
secs
mins
.12
hours
PIE1, TMR1IE
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
secs
mins, F
.59
mins
hours, F
.23
.01
hours
ADIE
ADIP
ADIF
Bit 6
—
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu
TMR0IE
RCIE
RCIP
RCIF
Bit 5
; 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
Bit 4
TXIF
TXIE
TXIP
SSPIF
SSPIE
SSPIP
RBIE
Bit 3
TMR0IF
CCP1IF
CCP1IE
CCP1IP
Bit 2
TMR2IF
TMR2IE
TMR2IP
INT0IF
Bit 1
TMR1IE
TMR1IP
TMR1IF
Bit 0
RBIF
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0111 1111 0111 1111
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
POR, BOR
Value on
DS39609B-page 139
Value on
all other
Resets