PIC18LF442-I/PT Microchip Technology, PIC18LF442-I/PT Datasheet - Page 4

• Manufacturer Part Number: PIC18LF442-I/PT
• Description: IC MCU FLASH 8KX16 A/D 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF442-I/PT

• Core Size: 8-Bit
• Program Memory Size: 16KB (8K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC18
• No. Of I/o's: 34
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 768Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TIMER1 MODULE
EXAMPLE 1:
EXAMPLE 2:
EXAMPLE 3:
DS80233C-page 4
Note:
ISR @ 0x004
RELOAD
EXIT
ISR @ 0x0008
HIGHINT
ISR @ 0x0018
RELOAD
EXIT
MOVWF
MOVF
MOVWF
BANKSEL PIR
BTFSS
GOTO
BSF
MOVF
MOVWF
SWAPF
SWAPF
RETFIE
BRA
BTFSC
BSF
RETFIE FAST
MOVFF
MOVFF
MOVFF
BTFSS
BRA
BSF
MOVFF
MOVFF
MOVFF
RETFIE
These instructions are required based on the function of the ISR. If the only code in the ISR is to reload
Timer1, then they are not required, but may be required if additional code is added.
HIGHINT
PIR,TMRIF
TMR1H,7
STATUS,STATUS_TEMP
WREG,WREG_TEMP
BSR,BSR_TEMP
PIR,TMRIF
EXIT
TMR1H,7
BSR_TEMP,BSR
WREG_TEMP,WREG
STATUS_TEMP,STATUS
PIC12/PIC14/PIC16 INTERRUPT SERVICE ROUTINE
w_temp
STATUS,w
status_temp
PIR,TMRIF
EXIT
TMR1H,7
status_temp,w
STATUS
w_temp,f
w_temp,w
PIC18 HIGH PRIORITY INTERRUPT SERVICE ROUTINE
PIC18 LOW PRIORITY INTERRUPT SERVICE ROUTINE
; (3-4Tcy), fixed interrupt latency
; (1Tcy), save off current W register contents
; (1Tcy), move status register into W register
; (1Tcy), save off contents of STATUS register
; (2Tcy), choose correct SFR bank
; (2Tcy), did a Timer1 overflow occur?
; No
; (1Tcy) Yes, reload for a 1 second overflow
; retrieve copy of STATUS register
; restore pre-isr STATUS register contents
; restore pre-isr W register contents
Total = 11-12 T
; (3-4Tcy), fixed interrupt latency
; (2Tcy), go to high priority interrupt routine
; (1Tcy), did a Timer1 overflow occur?
; (1Tcy) Yes, reload for a 1 second overflow
Total = 7-8 T
; (3-4Tcy), fixed interrupt latency
; (2Tcy), save STATUS register
; (2Tcy), save working register, refer to note 1
; (2Tcy), save BSR register, refer to note 1
; (2Tcy), did a Timer1 overflow occur?
; No
; (1Tcy) Yes, reload for a 1 second overflow
;restore BSR register, refer to note 1
;restore working register, refer to note 1
;restore STATUS register
Total = 12-13 T
CY
CY
CY
(if Timer1 overflow occurred)
(if Timer1 overflow occurred)
(if Timer1 overflow occurred)
© 2007 Microchip Technology Inc.