MDK-ARM Keil, MDK-ARM Datasheet - Page 19

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Getting Started: Building Applications with RL-ARM
RTX Kernel
RTX consists of a scheduler that supports round-robin, pre-emptive, and co-
operative multitasking of program tasks, as well as time and memory
management services. Inter-task communication is supported by additional
RTOS objects, including event triggering, semaphores, Mutex, and a mailbox
system. As we will see, interrupt handling can also be accomplished by
prioritized tasks, which are scheduled by the RTX kernel.
The RTX kernel contains a
scheduler that runs program code
as tasks. Communication
between tasks is accomplished
by RTOS objects such as events,
semaphores, Mutexes, and
mailboxes. Additional RTOS
services include time and
memory management and
interrupt support.
Tasks
The building blocks of a typical C program are functions that we call to perform
a specific procedure and which then return to the calling function. In an RTOS,
the basic unit of execution is a “Task”. A task is very similar to a C procedure,
but has some fundamental differences.
We always expect to return from C functions, however, once started an RTOS
task must contain an endless loop, so that it never terminates and thus runs
forever. You can think of a task as a mini self-contained program that runs
within the RTOS. While each task runs in an endless loop, the task itself may be
started by other tasks and stopped by itself or other tasks. A task is declared as a
C function, however RTX provides an additional keyword __task that should be
added to the function prototype as shown above. This keyword tells the compiler
Procedure
unsigned int procedure (void)
}
…
…
return (val);
{
Task
__task void task (void)
}
for (;;) {
}
…
{
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