PIC18F4520-I/P Microchip Technology, PIC18F4520-I/P Datasheet - Page 105

• Manufacturer Part Number: PIC18F4520-I/P
• Description: IC MCU FLASH 16KX16 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4520-I/P

• Program Memory Type: FLASH
• Program Memory Size: 32KB (16K x 16)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1536 B
• Interface Type: MSSP, SPI, I2C, PSP, USART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 1 x 8
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, 53275-917, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136, DM163022
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 13 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: DVA18XP400 - DEVICE ADAPTER 18F4220 PDIP 40LD444-1001 - DEMO BOARD FOR PICMICRO MCUACICE0206 - ADAPTER MPLABICE 40P 600 MIL
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

9.6
External interrupts on the RB0/INT0, RB1/INT1 and
RB2/INT2 pins are edge-triggered. If the corresponding
INTEDGx bit in the INTCON2 register is set (= 1), the
interrupt is triggered by a rising edge; if the bit is clear,
the trigger is on the falling edge. When a valid edge
appears on the RBx/INTx pin, the corresponding flag
bit, INTxF, is set. This interrupt can be disabled by
clearing the corresponding enable bit, INTxE. Flag bit,
INTxF, must be cleared in software in the Interrupt
Service Routine before re-enabling the interrupt.
All external interrupts (INT0, INT1 and INT2) can wake-
up the processor from Idle or Sleep modes if bit INTxE
was set prior to going into those modes. If the Global
Interrupt Enable bit, GIE, is set, the processor will
branch to the interrupt vector following wake-up.
Interrupt priority for INT1 and INT2 is determined by the
value contained in the interrupt priority bits, INT1IP
(INTCON3<6>) and INT2IP (INTCON3<7>). There is
no priority bit associated with INT0. It is always a high
priority interrupt source.
EXAMPLE 9-1:
 2004 Microchip Technology Inc.
MOVWF
MOVFF
MOVFF
;
; USER ISR CODE
;
MOVFF
MOVF
MOVFF
INTn Pin Interrupts
W_TEMP
STATUS, STATUS_TEMP
BSR, BSR_TEMP
BSR_TEMP, BSR
W_TEMP, W
STATUS_TEMP, STATUS
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
PIC18F2420/2520/4420/4520
Preliminary
; W_TEMP is in virtual bank
; STATUS_TEMP located anywhere
; BSR_TMEP located anywhere
; Restore BSR
; Restore WREG
; Restore STATUS
9.7
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh
16-bit mode, an overflow in the TMR0H:TMR0L regis-
ter pair (FFFFh
can be enabled/disabled by setting/clearing enable bit,
TMR0IE (INTCON<5>). Interrupt priority for Timer0 is
determined by the value contained in the interrupt pri-
ority bit, TMR0IP (INTCON2<2>). See Section 11.0
“Timer0 Module” for further details on the Timer0
module.
9.8
An input change on PORTB<7:4> sets flag bit, RBIF
(INTCON<0>). The interrupt can be enabled/disabled
by setting/clearing enable bit, RBIE (INTCON<3>).
Interrupt priority for PORTB interrupt-on-change is
determined by the value contained in the interrupt
priority bit, RBIP (INTCON2<0>).
9.9
During interrupts, the return PC address is saved on
the stack. Additionally, the WREG, Status and BSR reg-
isters are saved on the fast return stack. If a fast return
from interrupt is not used (see Section 5.3 “Data
Memory Organization”), the user may need to save
the WREG, Status and BSR registers on entry to the
Interrupt Service Routine. Depending on the user’s
application, other registers may also need to be saved.
Example 9-1 saves and restores the WREG, Status
and BSR registers during an Interrupt Service Routine.
TMR0 Interrupt
PORTB Interrupt-on-Change
Context Saving During Interrupts
0000h) will set TMR0IF. The interrupt
00h) will set flag bit, TMR0IF. In
DS39631A-page 103