gpio use in a task based on freertos

eric

Hi TI,

I am confused by this phenomenon when test a gio output in RM48HDK.

If I put the gioInit() in the beginning of a task, the gio manipulation failed.

If I put the gioInit() in the beginning of the main (that is before the running of the task), the gio manipulation success.

I attach my project also. It is a IAR(7.1) project based on the RM48HDK. (HCG 04.05.02)3582.IAR_RM48_GPIO_FreeRTOS_TEST.zip

over 9 years ago

0 Bob Crosby over 9 years ago

TI__Guru 72500 points

The first instruction in the function gioInit is to bring the GIO module out of reset by writing to the GCR0 register. This write must be done in privileged mode. Inside the tasks of FreeRTOS you are in user mode. That is why the gioInit function does not work when placed inside of a task. The gioInit function should be called one time before executing any tasks.

0 Anthony F. Seely over 9 years ago in reply to Bob Crosby

TI__Guru 69070 points

You can use the xTaskCreateRestricted API of FreeRTOS to create a task that runs with privilege.
Please consult the FreeRTOS documentation.

0 eric over 9 years ago in reply to Anthony F. Seely

Intellectual 885 points

Hi Anthony,

I have tested what you suggested. It works.

Best Regards,

Eric

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gpio use in a task based on freertos