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This module describes the basics of the TI DSP/BIOS Task Module (TSK).

Introduction

DSP/BIOS provides several different managers manage threads of execution. One of them is the Task Manager (TSK). This module explains the basics of TSK objects and use. This module only explains the use of static TSK objects which are set up using the configuration tool.

Reading

  • SPRU423 TMS320 DSP/BIOS Users Guide: Read the section on Tasks

Tsk module

Tasks are independent threads of code that conceptually run concurrently. The processor time is shared among the tasks. Each task has a priority which is used to determine which task gets processor time.

Each task has its own stack to store local variables, nesting function calls and for saving the task state when it is preempted. The stack size can be set individually for each task.

A task is always in one of four states

  • Running , which means the task is the one actually executing on the system’s processor;
  • Ready , which means the task is scheduled for execution subject to processor availability;
  • Blocked , which means the task cannot execute until a particular event occurs within the system; or
  • Terminated , which means the task is “terminated” and does not execute again.

Figure 1 shows a state transition diagram for a task. There is only one thread in the TSK_RUNNING state. When a task is in the TSK_RUNNING state all the other tasks in the TSK_READY state are at the same or lower priority. When a task of higher priority enters the TSK_READY state a preemption immediately occurs and the running task enters the TSK_READY state and the higher priority task enters the TSK_RUNNING state. Tasks can become blocked when a resource is unavailable or when some other event that causes blocking occurs. Semaphores are used to synchronize access to resources and can cause a task to block. When the resource becomes available the task enters the TSK_READY state.

State transition diagram for a task

To create a TSK object, open the configuration file, right click on Scheduling->TSK and select Insert TSK . You can right click on the object and select Properties to change its properties. Set the TSK priority on the General tab. Click on the Function tab and put the function name (preceded by an underscore) in for the function you want to handle the TSK. Figure 2 shows a view of the configuration file where the TSKs can be seen in their corresponding priority. Notice that the TSK_idle is priority 0 and it is reserved. This is the idle task.

When your program runs, the tasks with the same priority will get initialized in the order that they are shown in the configuration tool.

Configuration file showing TSKs and priorities

There are many functions in the TSK module. Some of the more commonly used ones are:

  • TSK_disable - Disable DSP/BIOS task scheduler
  • TSK_enable - Enable DSP/BIOS task scheduler
  • TSK_yield - Yield processor to equal priority task
  • TSK_sleep - Delay execution of the current task

As an example, suppose there are two task at the same priority as shown in the configuration file in Figure 3. To set up the threads of execution, change the Function properties to _funTSK0 for task TSK0 and _funTSK 1 for task TSK1 as shown in Figure 4.

Configuration tool showing two tasks at Priority 1

Function name for the Task

Then the main.c file will need two functions funTSK0 and funTSK1 as shown in the following listing.

#include<std.h>#include<log.h>#include<tsk.h>#include "tskcfg.h"Void main() {}Void funTSK0() {LOG_printf(&trace, "TSK0 Start"); TSK_yield();LOG_printf(&trace, "TSK0 Main"); TSK_yield();LOG_printf(&trace, "TSK0 Finish"); }Void funTSK1(){ LOG_printf(&trace, "TSK1 Start"); TSK_yield();LOG_printf(&trace, "TSK1 Main"); TSK_yield();LOG_printf(&trace, "TSK1 Finish"); }

When the program starts, the TSK0 runs first since it is the first on the list under Priority 1. It will print one statement and then yield to another task at the same priority, which will be TSK1. TSK1 will then begin its execution. The result of the whole run is:

TSK0 Start TSK1 StartTSK0 Main TSK1 MainTSK0 Finish TSK1 Finish

Viewing objects

Whe debugging a project it is important to see the characteristics of the components in your project. When using DSP/BIOS in CCS it is possible to view the DSP/BIOS objects and their properties using the RTSC Object Viewer (ROV). RTSC is Real Time Software Components which is a standard for developing software modules/libraries.

To view the DSP/BIOS v5.x objects and properties in the debug mode, select Tools->ROV . This will bring up a window that looks like the following figure.

RTSC Object Viewer

This figure shows the TSK module and the two tasks in the project. Notice the different properties that can be seen for each task.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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Source:  OpenStax, Ti dsp/bios lab. OpenStax CNX. Sep 03, 2013 Download for free at http://cnx.org/content/col11265/1.8
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