Issue with Low Voltage detect and reset on S32K144

[akumars4]

Hi,

I wanted to configure Low voltage detect and low voltage reset in my S32K144 device.

Case 1: I was successfully able to generate the interrupt on LVDF when LVDIE is set in LVDSC1. The breakpoint hits the ISR when I reduce the voltage on the supply less than VLVD 2.875V .

/***********Code ***********/

IP_PMC->LVDSC1 |= PMC_LVDSC1_LVDIE_MASK; /* Enable Low Voltage Detect Interrupt */

/***************************/

Case2: I enabled both LVDIE and LVDRE at the same time. But with this configuration when I reduce the voltage on the supply less than VLVD 2.875V the debugger connection is lost which means the controller has reset and I have a UART print statement based on reset reason due to LVD. 

/***********Code ***********/

IP_PMC->LVDSC1 |= (PMC_LVDSC1_LVDRE_MASK | /* Enable Low Voltage Reset */
                                             PMC_LVDSC1_LVDIE_MASK); /* Enable Low Voltage Detect Interrupt */

/***************************/

But according to the datasheet typical VLVD = 2.875V and VLVR = 2.58V

Can anyone tell me is this a expected behavior?

Regards

Ajeeth Kumar

S32K144EVB 

[davidtosenovjan · Accepted solution]

If you have set LVDRE (as you have) then reset is triggered below V_lvd threshold.

If LVDRE is cleared, then reset will be triggered below V_lvr threshold.

So yes, it is expected.

[akumars4]

Thanks for your swift reply.
So I can either enable LVDRE or LVD interrupt. right ?

[davidtosenovjan]

Yes, correct.