Create New RTX_Config.c

RL-ARM provides several versions of the RTX_Config.c file for ARM7™/ARM9™ RTX Kernel library. Each one configures the RTX kernel for a specific ARM device variant that RL-ARM supports. However the ARM family of devices is growing quickly, and it is possible that RL-ARM does not contain the configuration file for the device you use. In this case, you can take the RTX_Config.c file for the NXP device as a template and modify it for your particular ARM device.

RTX Kernel library for Cortex™-M has only one configuration file RTX_Conf_CM.c, which is common for all Cortex™-M device variants.

HW Resources Required

In order to run the RTX kernel, the following hardware resources are required from an ARM device:

• Peripheral Timer for generating periodic ticks. It is better to use a peripheral timer with an auto-reload function. RTX also supports timers with manual timer (or counter) reload. However, this can generate jitter and inaccuracy in the long run. The RTX kernel needs a count-up timer. If the timer used is a count-down timer, you need to convert the timer value.
• Timer Interrupts to interrupt the execution of a task and to start the system task scheduler.
• Forced Interrupts to force a timer interrupt when isr_ functions are used. If an isr_ function is called, the kernel forces the timer interrupt immediately after the interrupt ends. The forced timer interrupt activates the task scheduler. It is possible that a task has become ready. If this task has a higher priority than the currently running task, a task switch must occur.

All hardware dependent definitions are extracted from the code and defined with configuration macros. This makes it possible to customize the configuration without modifying the code.

Note

• The RTX configuration files are located in the \Keil\ARM\RL\RTX\Config directory.