Could not read the Interrupt Priority after vTaskStartScheduler()

[ebast]

Hi All,

I want to use NVIC_GetPriority(DMA1_Channel4_IRQn) function with FreeRtos. I can use this function before the vTaskStartScheduler(); but, when I call NVIC_GetPriority(DMA1_Channel4_IRQn) function after vTaskStartScheduler();, it does not work do you have any suggestion?

#include <FreeRTOS.h>
#include <queue.h>
#include <task.h>
/* -- */
static void vTest_NVIC( void *pvParameters )
{
 tprintf("\r\nTask Started..."); 
 /* -- */
 while(1) {
 /* -- */ 
 taskENTER_CRITICAL(); 
 tprintf("\r\npriority= %d",NVIC_GetPriority(DMA1_Channel4_IRQn));	
 taskEXIT_CRITICAL();
 	vTaskDelay(3000);;		
 }
}
int main()
{
 portBASE_TYPE xReturn;		
 /* -- */
 xReturn = xTaskCreate ( vTest_NVIC, ( const signed portCHAR * const )"Test_NVIC", configMINIMAL_STACK_SIZE<<4, NULL, tskIDLE_PRIORITY, NULL );
 if( xReturn != pdPASS ) {
 tprintf("\n\rTest_NVIC initilisation problem.\n\r");
 }
 
 NVIC_InitTypeDef NVIC_InitStructure;
 NVIC_SetPriorityGrouping(3);
 /* DMA1 Channel4 interrupt setting */
 NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 11;
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
 NVIC_Init(&NVIC_InitStructure);	
 
 tprintf("\r\npriority= %d",NVIC_GetPriority(DMA1_Channel4_IRQn)); 
 /* Now all the tasks have been started - start the scheduler. */
 vTaskStartScheduler();

The output of the program is like that.

priority= 11
 
Task Started...

Do you have any suggestions? thanks from now