9
DSP/BIOS and RTDX Using MATLAB, Visual C++, Visual Basic, and LabVIEW
A number of examples in this chapter illustrate the use of the DSP/BIOS real-time operating system and the real-time data exchange module RTDX.
DSP/BIOS provides real-time scheduling, analysis, and data transfer capabilities for an application running on a Texas Instruments DSP. RTDX allows the exchange of data, in real time, between a DSP and an application running on a host computer. Examples are given of host applications using MATLAB, Visual C++, Visual Basic, and LabVIEW.
9.1 INTRODUCTION TO DSP/BIOS
The following examples introduce some of the real-time scheduling and real-time analysis features of DSP/BIOS. Example programs from previous chapters are adapted to run as DSP/BIOS applications.
DSP/BIOS Threads
At the heart of DSP/BIOS is a preemptive real-time scheduler. This determines which one of a number of different threads is executed by the DSP at any given time. Threads are DSP/BIOS objects that contain program code (functions). The scheduler determines which thread to execute according to its type, priority, and other object properties. There are several different types of thread that can be used in a DSP/BIOS application.
- Hardware interrupts (HWIs) have the highest priority in a DSP/BIOS application. Their execution is triggered by interrupts from on-chip peripherals or external devices and they always run to completion. HWI threads are not preempted by any other threads. For that reason, HWIs ...
