Experiment 5 Interface of the 8088 MPU with 8254 PTC and 8255 PPI

  How time flies.Now we have to do the experiment 5.This course requires us to do 6 Experiment and 1 mini project.So you see ,we don't have many chances to do experiment.The last four experiments makes me know better about the Microprocessor and the function of the chips.So I have a confidence to do this experiment well.

  In this experiment ,our mission is to write the program in Assembly language,then we have to program this in the chips to control the LEDS and the buzzer.

8254A Programmable Timer Controller

The position of 8254A in PCB

  Since we have to know the basic knowledge of Assembly Language,we have to study how to get the meaning of a example code in the Experiment,which is a huge task.It is not the same as C language,and we have not use Assembly Language to make a program.

The program in Assembly Language

  There is always a question which confuses me for a long time,that is how the assembly language can make the chips in the CPU work.Why a series of ‘0’‘1’can command the computer to do so many things.Actually ,Assembly Language is fun.

Assembly Language is fun

  We have talked about the background of the Experiment 5 for such a long time,and now I will come back to the subject.Before we put the code into the chips, we have to wrap the wires to the certain pins of the chips ,just as the  photo in left side shows: 

  To be honest, it is not easy to connect the pins with wires, you have to concentrate because once you connected the wrong chips it will cost you much time to debug.And you have to make the length of the wire properly,either too long or too short wires may lead to error.

Tools for wrapping wires

You have to use the tools to remove the insulator.

  Then we wrap the metal part of the wires in the pins.And make sure we have to rotate clockwise.If you have made a mistake, you change the other side of the stick and rotate again.

  After the wrapping ,you may get a PCB like this:

Sample of the wrapped PCB

  Now let's come back the program,you just use the software to put your exe5.bin file into the 8254A,and connect the PCB to the power,you will get the result.

  This experiment is prepared for my final mini project, and I find that we have to be careful in each details.It is worthy for us to spend more time on the wrapping.Although it may cost more time ,but it will save time in debugging.Debug can make people crazy.And I think I should know more about the Assembly Language.

Reference::                           IERG 3810 Lab Mannul