DRA77P: PORZ after HALT command

Hi Aclemotte,

What is the use case can you give more details? Low power mode means what are the power domains that are
off? What is the state of MPU?

PORZ means will you not lose context?

Give us more details so that we can analyze and answer better.

- Keerthy

Hi Keerthy,

Use case: after a time programmable by SW, our system will call the HALT command to decrease the power consumption. An external signal will indicate to our system that it should return to a normal operating state, that is, the same as it was before the HALT command.

The state of MPU should be off. Maintaining context is not a requirement.

Hi Aclemotte,

Have you considered running powerOff?

If l look at the halt code:

void machine_halt(void)
{
local_irq_disable();
smp_send_stop();
while (1);
}

CPU Is basically busy looping.

Instead of that why not use Poweroff command? This will save power.

void machine_power_off(void)
{
local_irq_disable();
smp_send_stop();

if (pm_power_off)
pm_power_off();
}

Do you have any other core operational? If not poweroff seems to be better. PORZ seems good enough option.
What are your thoughts on the above?

Regards,
Keerthy

I'm designing the HW, so my main concern right now is around including everything necessary in our PCB to get out of the low-power state after the SW execute some low power command. We are using one of the two DSPs. Is the PORZ signal still valid to get out of this low power state?

Regards,