3.2 Tsk sem lab

Introduction

This lab module will help you become familiar with the TI DSP/BIOS TSK module and SEM module.

Reading

• SPRU423 TMS320 DSP/BIOS Users Guide: Read the sections on Semaphores and Tasks.

Lab module prerequisites

None

Laboratory

Part 1

• In this part we will create two tasks that will have the same priority and will run independent of each other.
• Follow the procedure in Code Composer Studio v4 DSP/BIOS Project to create a new CCS DSP/BIOS project. Name the project tsklab . Your project should have a DSP/BIOS configuration file named tsklab.tcf .
• Create a LOG object by right clicking on Instrumentation->LOG and selecting Insert LOG. Change the name to trace . Set its properties to have a length of 128 and be a fixed buffer.
• Create two TSKs with the following properties

1. Name: TSK0 , priority: 1, function: _funTSK0 .
2. Name: TSK1 , priority: 1, function: _funTSK1 .

• Create a main.c file and include a main function that does nothing.
• In the main.c file make functions for your TSKs, funTSK0 and funTSK1 . Each function should print to the trace LOG object once at the beginning of the function to indicate that the particular TSK is starting and once at the end of the function to indicate that the particular TSK is ending.
• Add code to each task that loops 5 times and prints to trace the task number and the loop number each time through the loop. It should look something like:

• The basic structure of main.c should be:

• Start the debug session.
• Open the log view by selecting Tools->RTA->Printf Logs .
• Run the program and record the results.

Part 2

• In this part we will change the tasks so that they yield to each other within their loops.
• Have in your system two TSKs with the following properties

1. Name: TSK0 , priority: 1, function: _funTSK0 .
2. Name: TSK1 , priority: 1, function: _funTSK1 .
3. Each yields to the other in their loop.

• Copy the main.c file from above to a new file main2.c . Exclude the main.c from your project build.
• Change the code so that the two tasks yield to each other within the loop. Put a print statement before the yield and one after the yield so you will know when the function has completed the loop. Do this for subsequent parts of this lab also.
• Start the debug session.
• Open the log view by selecting Tools->RTA->Printf Logs .
• Run the program and record the results.

Part 3

• In this part we will change the tasks so that one is a higher priority than the other. They yield to each other in their loops.
• Have in your system two TSKs with the following properties

1. Name: TSK0 , priority: 2, function: _funTSK0 .
2. Name: TSK1 , priority: 1, function: _funTSK1 .
3. Each yields to the other in their loop.

• This part will still be executing main2.c .
• Set TSK0 to a higher priority than the other.
• Start the debug session.
• Open the log view by selecting Tools->RTA->Printf Logs .
• Run the program and record the results.
• Does the execution appear different from part 2?