pic16f84

Description: The Microchip PIC 16C84 was one of the first serial in-system programmable microcontrollers. PIC serial programmers were published in electronic magazines in 1993. Currently, numerous PIC programmer circuits for serial and parallel PC ports are available on the Internet. Despite its somewhat unconventional design, including 128-byte page RAM/Register direct and indirect memory mapping, it remains a popular microcontroller, now available and programmable as the flash microcontroller 16F84. The MPLAB development environment from Microchip is free of charge, and many application examples are accessible. A serial programmer is preferred, as it does not require an external power supply and draws power from the PC's RS232 connection. The circuit functions well with laptop computers, even with their often lower RS232 voltages. The 9-pin female connector (CON1) connects directly to the PC's serial output. It is not intended as a production programmer, so it does not include a ZIF socket; an open IC socket should be used instead. A 1:1 PCB layout is available as a PDF file named pic16f84.pdf. The PCB package used locates the layout at the bottom of the page. The PCB etching page should be viewed to produce the PCB. Programming software and application examples can be found through various online resources.

The Microchip PIC 16C84 microcontroller is a notable device in the realm of embedded systems, primarily due to its early adoption of in-system programming capabilities. This feature allows users to program the microcontroller while it is installed in the circuit, offering significant convenience during development and debugging phases. The transition from the PIC 16C84 to the more advanced PIC 16F84 introduced flash memory technology, enhancing programmability and reliability.

The serial programmer circuit designed for this microcontroller is particularly advantageous because it operates without the need for an external power supply. It utilizes the power available from the RS232 connection of the PC, making it suitable for portable applications, especially with laptops that may have different voltage levels on their serial ports. The design includes a 9-pin female connector (CON1) that interfaces directly with the PC's serial output, allowing for straightforward connectivity and ease of use.

The absence of a ZIF (Zero Insertion Force) socket indicates that this programmer is not intended for high-volume production but rather for prototyping and development purposes. Instead, an open IC socket is recommended for inserting the PIC microcontroller, facilitating easier replacement and testing.

The PCB layout for the programmer is provided in a 1:1 scale PDF format, ensuring that users can accurately reproduce the circuit board for their applications. The PCB manufacturing process involves etching, and the specific layout can be found at the bottom of the provided documentation. Additionally, the MPLAB development environment offers a wealth of programming software and application examples, further supporting developers in their projects involving the PIC 16C84 and 16F84 microcontrollers. This comprehensive ecosystem of tools and resources contributes to the ongoing popularity of these microcontrollers in various electronic applications.The Microchip PIC 16C84 was one of the first serial in-system programmable microcontroller. I saw PIC serial programmers published in Electronic magazines in 1993. Today, many PIC programmer circuits - for serial and parallel PC ports - are published on the Internet. Despite its somewhat unusual design - like the 128 byte page RAM/Register direct/ indirect memory mapping - it is a popular microcontroller, easily available and programmable now as flash microcontroller 16F84. The developer environment MPLAB from Microchip is free of charge and many application examples are available.

I prefer a serial programmer. It does not require an external power supply, it extracts power from the PC RS232 connection. The circuit below also works fine with laptop computers, despite their often too low RS232 voltages. The 9-pin female connector (CON1) connects directly to the PC serial output. It is not designed as a production programmer, so it lacks a ZIF-socket. Use an open IC-socket instead. The 1:1 PCB layout is available as PDF formatted file: pic16f84. pdf. The PCB package I use locates the layout at the bottom of the page. View the PCB etching page to produce the PCB. Programming software and application examples could be found for example at the links of, or.