topic Re: Task with priority 8 and kernel isr how works the system? in MQX Software Solutions

Task with priority 8 and kernel isr how works the system?

admin — Wed, 27 Oct 2010 20:38:42 GMT

Hi,

I have a system that works with MQX RTOS 3.5 on Coldifire MCF52259 one task always active with priority 8 plus a kernel isr

TASK_TEMPLATE_STRUCT MQX_template_list[] =
{
// Task number, Entry point, Stack, Pri, String, Auto?
{ MAIN_TASK, Main_task, 5000, 8, "main_prof", MQX_AUTO_START_TASK, 0L, 0},
{ 0, 0, 0, 0, 0, 0, 0L, 0 }
};

#define GPT0_INTERRUPT_LEVEL 7
#define GPT0_INTERRUPT_PRIORITY 7

_int_install_kernel_isr(MCF5225_INT_TIMA_C0F,(void (_CODE_PTR_)(void))isrINT_CF0);

_mcf5225_int_init(MCF5225_INT_TIMA_C0F,GPT0_INTERRUPT_LEVEL,GPT0_INTERRUPT_PRIORITY,TRUE);

With this configuration, when my hw interrupt starts, the system blocks the task and execute the interrupt or I need to use task queue inside interrupt kernel for suspending the task?

Re: Task with priority 8 and kernel isr how works the system?

admin — Wed, 27 Oct 2010 22:24:09 GMT

Reading the MQX User guide I see there are restrictions on ISRs, so if I use a kernel interrupt I can't use _taskq_suspend()
_taskq_suspend_task()

these restrictions are valid also for kernel interrupts?

Re: Task with priority 8 and kernel isr how works the system?

PetrL — Mon, 01 Nov 2010 04:01:36 GMT

The kernel isr is not handled by MQX at all - it must not call any MQX function.

You should pass information to other tasks (if required) by an application-implemented mechanism (usually
ring buffers with head and tail pointers and total size fields).

For more information see Reference Manual chapter:

2.1.45 _int_install_kernel_isr

PetrL

Re: Task with priority 8 and kernel isr how works the system?

Geek19 — Thu, 09 Aug 2012 02:41:43 GMT

Hi Shinji,

I am having difficulty getting my kernel interrupt working for me, I do not know how/what to save/restore before and after my function call in kernel ISR, I was wondering if you could explain to me about your approach on how you are doing your kernel ISR?

Thanks;

Geek19