PIC18F4550 Pin Diagram_0



PIC18F4550 is an 8-bit microcontroller of PIC18 family. PIC18F family is based on 16-bit instruction set architecture. PIC18F4550 consists of 32 KB flash memory, 2 KB SRAM and 256 Bytes EEPROM.


This is a 40 pin PIC Microcontroller consisting of 5 I/O ports (PORTA, PORTB, PORTC, PORTD and PORTE). PORTB and PORTD have 8 pins to receive/transmit 8-bit I/O data. The remaining ports have different numbers of pins for I/O data communications.


PIC18F4550 can work on different internal and external clock sources. It can work on a varied range of frequency from 31 KHz to 48 MHz. PIC18F4550 has four in-built timers. There are various inbuilt peripherals like ADC, comparators etc in this controller.


PIC18F4550 is an advanced microcontroller which is equipped with enhanced communication protocols like EUSART, SPI, I2C, USB etc.



Pin Description: 

Pin No. Name Description Alternate Function
1 MCLR/VPP/RE3 Master clear Vpp: programming voltage inputRE3: I/O pin of PORTE, PIN 3
2 RA0/AN0 PortA I/O Pins 1-6 AN0: Analog input 0
3 RA1/AN1 AN1: Analog input 1
4 RA2/AN2/VREF-/CVREF AN2: Analog input 2VREF-: A/D reference voltage (low) input.CVREF: Analog comparator reference output.
5 RA3/AN3/VREF+ AN3: Analog input3VREF+: A/D reference voltage (high) input
6 RA4/T0CKI/C1OUT/RCV T0CKI: Timer0 external clock input.C1OUT: Comparator 1 outputRCV:External USB transceiver RCV input.
7 RA5/AN4/SS/HLVDIN/C2OUT AN4: Analog input 4SS: SPI slave select inputHLDVIN: High/Low-Voltage Detect input.

C2OUT: Comparator 2 output.

8 RE0/AN5/CK1SPP PortE I/O Pins 1-3 AN5: Analog input 5CK1SPP: SPP clock 1 output.
9 RE1/AN6/CK2SPP AN6: Analog input 6CK2SPP: SPP clock 2 output
10 RE2/AN7/OESPP AN6: Analog input 7OESPP : SPP Enabled output
11 VDD Positive supply
12 Vss Ground
13 OSC1/CLKI Oscillator pin 1 CLKI: External clock source input
14 OSC2/CLKO/RA6 PortE I/O Pin 7 CLKO: External clock source outputOSC2: Oscillator pin 2
15 RC0/T1OSO/T13CKI PortC I/O Pins 1-3 T1OSO :Timer1 oscillator outputT13CKI: Timer1/Timer3 external clock input.
16 RC1/T1OSI/CCP2/UOE T1OSI: Timer1 oscillator outputCCP2:Capture 2 input/Compare 2 output/PWM2 outputUOE: External USB transceiver OE output
17 RC2/CCP1/P1A CCP1: Capture 1 input/Compare 1 output/PWM1 output.P1A :Enhanced CCP1 PWM output, channel A.
18 VUSB Internal USB 3.3V voltage regulator output, positive supply for the USB transceiver.
19 RD0/SPP0 PortD I/O Pins 1-4 SPP0-SPP4Streaming Parallel Port data
20 RD1/SPP1
21 RD2/SPP2
22 RD3/SPP3
23 RC3/D-/VM PortC I/O Pins 4-5 D-: USB differential minus line (input/output)VM: External USB transceiver VM input.
24 RC4/D+/VP D+: USB differential plus line (input/output).VP: External USB transceiver VP input.
25 RC6/TX/CK PortC I/O Pins 7-8 TX: EUSART asynchronous transmit.CK: EUSART synchronous clock (see RX/DT).
26 RC7/RX/DT/SDO RX: EUSART asynchronous receive.DT: EUSART synchronous data (see TX/CK).SDO: SPI data out.
27 RD4/SPP4 PortD I/O Pins 5-8 SPP4:Streaming Parallel Port data
28 RD5/SPP5/P1B SPP5:Streaming Parallel Port dataP1B: Enhanced CCP1 PWM output, channel B
29 RD6/SPP6/P1C SPP6:Streaming Parallel Port dataP1C: Enhanced CCP1 PWM output, channel C
30 RD7/SPP7/P1D SPP7:Streaming Parallel Port dataP1D: Enhanced CCP1 PWM output, channel D
31 Vss Ground
32 VDD Positive supply
33 RB0/AN12/INT0/FLT0/SDI/SDA PortB I/O Pins 1-8 AN12: Analog input 12.INT0: External interrupt 0.FLT0: Enhanced PWM Fault input (ECCP1 module).

SDI: SPI data in.

SDA: I2C data I/O.

34 RB1/AN10/INT1/SCK/SCL AN10: Analog input 10.INT1: External interrupt 1.SCK: Synchronous serial clock input/output for SPI mode.

SCL: Synchronous serial clock input/output for I2C mode.

35 RB2/AN8/INT2/VMO AN8: Analog input 8.INT2: External interrupt 2.VMO: External USB transceiver VMO output.
36 RB3/AN9/CCP2/VPO AN9: Analog input 9.CCP2: Capture 2 input/Compare 2 output/PWM2 output.VPO: External USB transceiver VPO output.
37 RB4/AN11/KBI0/CSSPP AN11: Analog input 11.KBI0: Interrupt-on-change pin.CSSPP: SPP chip select control output.
38 RB5/KBI1/PGM KBI1: Interrupt-on-change pin.PGM: Low-Voltage ICSP Programming enable pin.
39 RB6/KBI2/PGC KBI2: Interrupt-on-change pin.PGC: Low-Voltage ICSP Programming enable pin.
40 RB7/KBI3/PGD KBI3: Interrupt-on-change pin.PGD: In-Circuit Debugger and ICSP programming data pin.