8/24/2021

16f628a Simple Programming

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Read about 'Programming PIC 16F628A' on element14.com. I am looking for someone in the USA who has a PIC programmer and who would be willing to put a Program that I already have on a couple of PIC16F628 chips. This is because the pic 16f648a / 16f628a is an 8-bit microcontroller this means that we can store any binary number from all zeros 00000000 to all ones 11111111 (all zeros in binary 0000000 is equal to zero decimal 0) and (all ones in binary 11111111 is equal to 255 decimal) this means that there are 256 combinations within each 8-bit variable. Softlog SEC-DS Secure Programming Upgrade for ICP2 Programmers ( SW500090 ) The Softlog SEC-DS Secure Programming Upgrade is a 'Secure Programming' extension for the ICP2 and ICP2(HC) programmers that provides several layers of protection-utilizing breakthrough technology-dramatically reducing the risk of unauthorized reconstruction of hex data and limiting how many times a hex file. The PIC processor is based on advanced RISC architecture and comes with 35 instruction set that is simple to use and easy to configure. Like some controllers in the PIC community, the PIC16F628a features operating range around 2 to 5.5 V where the temperature range is -40 to 125 °C. Programmable memory size is 3.5 KB and SRAM is 224 bytes. The PIC16F628A has a PGM pin that it uses in LVP (Low Voltage Programming) mode. It shares the same pin as RB4. The PGM pin must be tied to ground under normal operation and pulled high during programming (your programmer should pull it high during a programming sequence).

Introduction

Welcome to the start of the PIC Tutorial. These pages will take you form the basic structure of the device, right through to programming methods and techniques. Also, there will be suggestions on how to modify the code so that you can adapt the PIC to suit your applications within Cybot. We will not be including any internal architecture diagrams, as this may only lead to confusion. If you want to look at the datasheet, then this can be downloaded from Microchips' web site.

To start, let us take a look at the PIC.

Microchip PIC 16F84 Microcontroller

Microchip manufacture a series of microcontrollers called PIC. You can see the range of their microcontrollers here. There are many different flavours available, some basic low memory types, going right up through to ones that have Analogue - To- Digital converters and even PWM built in. We are going to concentrate on the 16F84 PIC. Once you have learnt how to program one type of PIC, learning the rest is easy.

There are several ways of programming the PIC - using BASIC, C, or Assembly Language. We are going to show you the Assembly Language. Don't be put off by this. There are only 35 instructions to learn, and it is the cheapest way to program the PICs, as you do not need any extra software other than the freebies.

The 16F84 Pins

Below is a diagram showing the pin-outs of the PIC 16F84. We will go through each pin, explaining what each is used for.

RA0 To RA4

RA is a bidirectional port. That is, it can be configured as an input or an output. The number following RA is the bit number (0 to 4). So, we have one 5-bit directional port where each bit can be configured as Input or Output.

RB0 To RB7

RB is a second bidirectional port. It behaves in exactly the same way as RA, except there are 8 - bits involved.

VSS And VDD

These are the power supply pins. VDD is the positive supply, and VSS is the negative supply, or 0V. The maximum supply voltage that you can use is 6V, and the minimum is 2V.

OSC1/CLK IN And OSC2/CLKOUT

These pins is where we connect an external clock, so that the microcontroller has some kind of timing.

MCLR

This pin is used to erase the memory locations inside the PIC (i.e. when we want to re-program it. In normal use it is connected to the positive supply rail.

INT

This is an input pin which can be monitored. If the pin goes high, we can cause the program to restart, stop or any other single function we desire. We won't be using this one much.

T0CK1

This is another clock input, which operates an internal timer. It operates in isolation to the main clock. Again, we won't be using this one much either.

How To Program The PIC

OK, so you haven't been put off so far. Now, you want to know how to program the PIC, but apart from learning the assembly code instructions, how do you go about actually programming the information in? Well, there are two ways - the easy way, and the DIY way. The easy way is to buy a PIC programmer (around £35), which will connect to your PC and you can program your PIC using the software provided. The DIY way is to build your own programmer (cheapest is just under £20) and use free software from the Internet and program it that way.

If you want to go for a DIY method, then We thoroughly recommend this site, and click on 'Supported Programmers' for circuits. The cheapest is TAIT Classic Programmer. Software for programming the PIC can also be downloaded from this site, under Download

If you want to go down an easier route, then check out this site. Here you can either buy a kit of parts or a ready made unit.

16f628a

Another good site for some FREE software is here This software allows you to use any programmer, as the software is fully configurable.

Either method will do, as they both result in the same thing - program a PIC.

The next thing you will need is an assembler. This converts the program that you write into a format that the PIC understands. The best one around is from Microchip themselves, called MPLAB. It is windows based, and includes an editor, simulator, and assembler. This is the de-facto software, as it is written by the manufacturers of the PIC, and above all it is FREE!

We also recommend using Breadboard to make your circuits up, while you are playing with the PIC. There are various sizes available, which come with their own costs. Check out the Maplin Electronics links on the home page for more details of prices etc.

16f628a Simple Programming Language

Next, we will look at how to connect up a simple circuit for PIC development.

Click here to Start Tutorial >>
(Connect to the PIC Microcontroller)

Introduction

Welcome to the start of the PIC Tutorial. These pages will take you form the basic structure of the device, right through to programming methods and techniques. Also, there will be suggestions on how to modify the code so that you can adapt the PIC to suit your applications within Cybot. We will not be including any internal architecture diagrams, as this may only lead to confusion. If you want to look at the datasheet, then this can be downloaded from Microchips' web site.

To start, let us take a look at the PIC.

Microchip PIC 16F84 Microcontroller

Microchip manufacture a series of microcontrollers called PIC. You can see the range of their microcontrollers here. There are many different flavours available, some basic low memory types, going right up through to ones that have Analogue - To- Digital converters and even PWM built in. We are going to concentrate on the 16F84 PIC. Once you have learnt how to program one type of PIC, learning the rest is easy.

There are several ways of programming the PIC - using BASIC, C, or Assembly Language. We are going to show you the Assembly Language. Don't be put off by this. There are only 35 instructions to learn, and it is the cheapest way to program the PICs, as you do not need any extra software other than the freebies.

The 16F84 Pins

Below is a diagram showing the pin-outs of the PIC 16F84. We will go through each pin, explaining what each is used for.

RA0 To RA4

RA is a bidirectional port. That is, it can be configured as an input or an output. The number following RA is the bit number (0 to 4). So, we have one 5-bit directional port where each bit can be configured as Input or Output.

RB0 To RB7

RB is a second bidirectional port. It behaves in exactly the same way as RA, except there are 8 - bits involved.

VSS And VDD

These are the power supply pins. VDD is the positive supply, and VSS is the negative supply, or 0V. The maximum supply voltage that you can use is 6V, and the minimum is 2V. First grademrs. macsmith's marvelous music site.

OSC1/CLK IN And OSC2/CLKOUT

These pins is where we connect an external clock, so that the microcontroller has some kind of timing.

MCLR

This pin is used to erase the memory locations inside the PIC (i.e. when we want to re-program it. In normal use it is connected to the positive supply rail.

INT

This is an input pin which can be monitored. If the pin goes high, we can cause the program to restart, stop or any other single function we desire. We won't be using this one much.

16f628a Simple Programming Manual

T0CK1

This is another clock input, which operates an internal timer. It operates in isolation to the main clock. Again, we won't be using this one much either.

How To Program The PIC

16f628a Simple Programming

OK, so you haven't been put off so far. Now, you want to know how to program the PIC, but apart from learning the assembly code instructions, how do you go about actually programming the information in? Well, there are two ways - the easy way, and the DIY way. The easy way is to buy a PIC programmer (around £35), which will connect to your PC and you can program your PIC using the software provided. The DIY way is to build your own programmer (cheapest is just under £20) and use free software from the Internet and program it that way.

If you want to go for a DIY method, then We thoroughly recommend this site, and click on 'Supported Programmers' for circuits. The cheapest is TAIT Classic Programmer. Software for programming the PIC can also be downloaded from this site, under Download

If you want to go down an easier route, then check out this site. Here you can either buy a kit of parts or a ready made unit.

16f628a Programmer

Another good site for some FREE software is here This software allows you to use any programmer, as the software is fully configurable.

Either method will do, as they both result in the same thing - program a PIC.

16f628a Simple Programming Instructions

The next thing you will need is an assembler. This converts the program that you write into a format that the PIC understands. The best one around is from Microchip themselves, called MPLAB. It is windows based, and includes an editor, simulator, and assembler. This is the de-facto software, as it is written by the manufacturers of the PIC, and above all it is FREE!

We also recommend using Breadboard to make your circuits up, while you are playing with the PIC. There are various sizes available, which come with their own costs. Check out the Maplin Electronics links on the home page for more details of prices etc.

Programming

Next, we will look at how to connect up a simple circuit for PIC development.

Click here to Start Tutorial >>
(Connect to the PIC Microcontroller)