PIC16F628A 8-bit PIC Microcontroller

29 October 2020 - 0 Comments

PIC16F628A PIC Microcontroller

PIC16F628A Pinout

PIC16F628A is a CMOS FLASH-based mid-range 8-bit microcontroller that comes with an 18-Pin package, out of which, 16 pins can be used as I/O pins. This microcontroller has 4 Mhz of internal oscillator with 128 bytes of EEPROM data memory, packed with a single Capture/Compare/PWM, and a USART module with 2 comparators. Low voltage programming is supported by this microcontroller unit.

PIC16F628A Pin Configuration

Pin Number	Pin Name	Description
1	RA2/AN2/VREF	Bidirectional I/O pin of port A bit 2 or Analog comparator input channel 2 or Analog Voltage Reference output
2	RA3/AN3/CMP1	Bidirectional I/O port or Analog comparator input or Comparator 1 output.
3	RA4/T0CKI/CMP2	Bidirectional I/O pin of port A bit 4 or timer 0 clock input or comparator channel 2 output.
4	RA5/MCLR/VPP	Input port or Master clear or Programming voltage input. When configured as MCLR, this pin is an active-low Reset to the device, mainly used for Programming or Port A bit 5 Pin.
5	VSS	Power Ground pin.
6	RB0/INT	Bidirectional I/O pin of port B bit 0 or External interrupt pin.
7	RB1/RX/DT	Bidirectional I/O pin of port B bit 1 or USART Recieve pin or synchronous data I/O.
8	RB2/TX/CK	Bidirectional I/O pin of port B bit 2 or USART Transmit pin or synchronous clock I/O.
9	RB3/CCP1	Bidirectional I/O pin of port B bit 3 or Capture compare PWM I/O.
10	RB4/PGM	Bidirectional I/O pin of port B bit 4 or Low voltage Programming pin.
11	RB5	Bidirectional I/O pin of port B bit 5.
12	RB6/T1OSC/T1CKI/PGC	Bidirectional I/O pin of port B bit 6 or Timer1 Oscillator output or Timer1 Clock input or ICSP Programming clock mainly used for Programming purposes.
13	RB7/T1OSI/PGD	Bidirectional I/O pin of port B bit 7 or Timer1 Oscillator input or ICSP Programming data mainly used for Programming purposes.
14	VDD	Positive Power Pin.
15	RA6/OSC2/CLKOUT	Bidirectional I/O pin of port A bit 6 or Oscillator crystal output or Clock out in RC/INTOSC
16	RA7/OSC1/CLKIN	Bidirectional I/O pin of port A bit 7 or Oscillator crystal input or External Clock input
17	RA0/AN0	Bidirectional I/O pin of port A bit 0 or Analog comparator input channel 0.
18	RA1/AN1	Bidirectional I/O pin of port A bit 1 or Analog comparator input channel 1

Features and Specification of the PIC16F628A Microcontroller

PIC16F628A - Simplified Features and Specification
CPU	Mid-Range 8-bit
Number of Pins	18
Operating Voltage (V)	2 - 5.5 V
Number of I/O pins	16
ADC Module	Nil
Timer Module	3
Comparators	2
DAC Module	Nil
Communication Peripherals	UART(1)
External Oscillator	Yes
Internal Oscillator	4 MHz
Program Memory (KB)	3.5 KB
CPU Speed (MIPS)	5
RAM Bytes	224 bytes
Data EEPROM	128 bytes

Note: Complete technical details can be found in the PIC16F628A Datasheet linked at the bottom of this page.

Alternative for PIC16F628A

Alternative products for PIC16F628A microcontroller are listed below-

PIC12F629
PIC12F683
PIC16F505
PIC12F508
PIC16F676
PIC16F72
PIC16F873A
PIC16F876A
PIC16F886
PIC16F252

Other 8-bit Microcontroller

PIC16F1503

Introduction to PIC16F628A

PIC16F628A is a CMOS FLASH-based mid-range 8-bit microcontroller that comes with an 18-Pin package, out of which, 16 pins can be used as I/O pins. This microcontroller has 4 Mhz of internal oscillator with 128 bytes of EEPROM data memory, packed with a single Capture/Compare/PWM, and a USART module with 2 comparators. Low voltage programming is supported by this microcontroller unit.

PIC16F628A microcontroller also has two 8-bit and one 16-bit timer suitable for timing-related mid-range applications where different timers are required.

PIC16F628A works with 2V to 5.5V operations, thus it is suitable for 3.3V and 5.0V logic level applications. Brow-out Reset, Power-on Reset, Watchdog timer with an independent oscillator, Power-saving sleep modes are also supported by the PIC16F628A microcontroller. PIC16F628A pin mapping is shown below-

Detailed Features of PIC16F628A

PIC16F628A –Detailed Features
CPU	Mid-Range 8 - Bit
Architecture	8 - bit
Program Memory Size (Kbytes)	3.5 KB
RAM (bytes)	224 bytes
EEPROM/HEF	128 bytes
Pin Count	18
Max. CPU Speed (MHz)	20 MHz
Peripheral Pin Select (PPS)	No
Internal Oscillator	4 MHz
No. Of comparators	2
No. Of Operational Amplifier	Nil
No. Of ADC channels	Nil
Max ADC Resolution (bits)	-
ADC with Computation	No
Number of DAC Converter	Nil
Max DAC resolution	-
Internal Voltage Reference	2 - 5.5V
Zero Cross Detect	No
No. Of 8-bit timers	2
No. Of 16-bit Timers	1
Signal Measurement Timer	No
Hardware Limit Timer	No
No. Of PWM outputs	1
Max PWM resolution	1024
Angular Timer	No
Math Accelerator	No
No. Of UART module	1
No. Of SPI Module	Nil
No. Of I2C module	Nil
No. Of USB Module	Nil
Windowed Watchdog Timer (WWDT)	No
CRC/Scan	No
Numerically Controlled Oscillator	No
Cap. Touch Channels	Nil
Segment LCD	Nil
Minimum Operating Temperature (*C)	-40°C
Maximum Operating Temperature (*C)	125°C
Minimum Operating Voltage (V)	2 V
Maximum Operating Voltage (V)	5.5V
High Voltage Capable	No

Programming PIC Microcontroller

PIC microcontrollers can be programmed with different software that is available in the market. There are people who still use Assembly language to program PIC MCUs. The below details is for the most advanced and common software and compiler that has been developed by Microchip itself.

In order to program the PIC microcontroller, we will need an IDE (Integrated Development Environment), where the programming takes place. A compiler, where our program gets converted into MCU readable form called HEX files. An IPE (Integrated Programming Environment), which is used to dump our hex file into our PIC MCUs.

IDE: MPLABX v3.35

IPE: MPLAB IPE v3.35

Compiler: XC8

Microchip has given all these three software for free. They can be downloaded directly from their official page. I have also provided the link for your convenience. Once downloaded, install them on your computer. If you have any problem doing so, you can post them in the comment below.

To dump or upload our code into PIC, we will need a device called PICkit 3. The PICkit 3 programmer/debugger is a simple, low-cost in-circuit debugger that is controlled by a PC running MPLAB IDE (v8.20 or greater) software on a Windows platform. The PICkit 3 programmer/debugger is an integral part of the development engineer's tool suite. A basic programming circuit for PIC16F628 is shown below.

PIC16F28A Programming Circuit

In addition to this, we will also need other hardware like a Perf board or breadboard, Soldering station, PIC ICs, Crystal oscillators, capacitors, etc.