Re: [lwip-users] stm32 ethernet interrup priority

[FreeRTOS Info]

On 22/08/2016 13:00, Erkan Ersoy wrote:
> Thank you Noam;
>
> Somethings are confusing but i think i get it

Yes, confusing.


> #define configKERNEL_INTERRUPT_PRIORITY (
> configLIBRARY_LOWEST_INTERRUPT_PRIORITY << (8 - configPRIO_BITS) )
> #define configMAX_SYSCALL_INTERRUPT_PRIORITY (
> configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY << (8 - configPRIO_BITS) )
>
> those values are
> configKERNEL_INTERRUPT_PRIORITY : 240
> configMAX_SYSCALL_INTERRUPT_PRIORITY: 80

Those values are used by FreeRTOS itself, which is portable across all 
ARM Cortex devices, which have varying number of implemented priority 
bits (in hardware).


> but they never used those defines so they used only values above 5
> without defines. Those defines stay there idle.

Some libraries want the full 8 bit values (which is how the hardware 
always sees the values), other libraries want unshifted values.


> I use 6 for ethernet interrupt and 7 for USART interrupt now it seems
> work fine

So 7 have a logically lower priority, despite being a higher numeric value.

The following link may make things clearer, or alternatively, murkier :o)

http://www.freertos.org/RTOS-Cortex-M3-M4.html

Regards,
Richard.

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