restricted peripheral access

[drk_tg]

Hi,

I want to access restricted peripheral: TIMER0. After small research found that I should use sd_ wrappers, in my case sd_nvic_SetPendingIRQ(TIMER0_IRQn) however I got always NRF_ERROR_SOC_NVIC_INTERRUPT_NOT_AVAILABLE error. How can I check if resource is currently used by softDevice? __sd_nvic_app_accessible_irq(TIMER0_IRQn) also gives always false.

[drk_tg]

I have enabled timeslot and my question is related to timeslot. I want to terminate timeslot so I'm calling:

timer0_enter_critical();
radio_enter_critical();
//__disable_irq();

// terminate immediately if in timeslot
if(m_timeslot.in_timeslot)// && __sd_nvic_app_accessible_irq(TIMER0_IRQn)) // start immediately if in timeslot
{
	// set session terminate flag
	m_timeslot.terminate_flag = true;

	// report when session is closed
	m_timeslot.external_session_close_flag = true;

	// stop and clear TIMER0
	NRF_TIMER0->TASKS_STOP 	 = 1;
	NRF_TIMER0->TASKS_CLEAR  = 1;

	// disable TIMER0 interrupts
	NRF_TIMER0->INTENCLR 	 = ((TIMER_INTENSET_COMPARE1_Enabled  << TIMER_INTENSET_COMPARE1_Pos)  & TIMER_INTENSET_COMPARE1_Msk);
	NRF_TIMER0->CC[1]    	 = 0;

	// clear and set pending TIMER0 interrupt
	NVIC_ClearPendingIRQ(TIMER0_IRQn);
	NVIC_SetPendingIRQ(TIMER0_IRQn);
}
else
{
	// set session terminate flag
	m_timeslot.terminate_flag = true;

	// report when session is closed
	m_timeslot.external_session_close_flag = true;
}

timer0_exit_critical();
radio_exit_critical();
//__enable_irq();

I'm setting m_timeslot.in_timeslot to true after NRF_RADIO_CALLBACK_SIGNAL_TYPE_START and to false after NRF_EVT_RADIO_SESSION_IDLE

and in static nrf_radio_signal_callback_return_param_t * m_timeslot_callback(uint8_t signal_type):

...

if(m_timeslot.terminate_flag)
{
	//SEGGER_SYSVIEW_Print("terminate_flag");
	//SEGGER_RTT_printf(0,"terminate_flag\n");

	m_timeslot.terminate_flag = false;

	NRF_PPI->CHENCLR 								   = ((PPI_CHEN_CH8_Enabled << PPI_CHEN_CH8_Pos) & PPI_CHEN_CH8_Msk);
	signal_callback_return_param.params.request.p_next = NULL;
	signal_callback_return_param.callback_action       = NRF_RADIO_SIGNAL_CALLBACK_ACTION_END;
	m_timeslot.in_timeslot    						   = false;

	return ( &signal_callback_return_param );
}

...

But after some time I'm landing in hard fault handler so I'm guessing that problem is accesing TIMER0 while it's used by softdevice.

[Øyvind Karlsen]

Inside the timeslot event there will be no SoftDevice activity, set up a timer to terminate or extend the timeslot when it runs out of scheduled time. If you do not end the timeslot in time you will hardfault. A simple implementation of this is described in the timeslot tutorial.