LPC MicrocontrollersのトピックLPC55S69 : exit from PowerDown mode

LPC55S69 : exit from PowerDown mode

EugeneHiihtaja — Fri, 20 Dec 2019 07:50:26 GMT

Hi !

In Datasheet is written :

"Power Library in SDK sets the flash wait states based on the frequency selected."

When MCU is exit from PowerDowm mode it is clocked by using FRO_12Mhz,

but in SDK examples you still call BOARD_BootClockFRO12M() after wakeup.

Can it be so that only line SystemCoreClock = BOARD_BOOTCLOCKFRO12M_CORE_CLOCK;

is need ?

All other setting is done by Powerlib already.

Is this so ?

xiangjun_rong — Wed, 25 Dec 2019 09:15:02 GMT

Hi, Eugene,

I think you are right, after sleep/deepsleep/powerdown, the cpu core clock is restored to FRO_12MHz, so the code line

BOARD_BootClockFRO12M(); is unnecessary. Because DEMO_PowerDownWakeup() is called after waking up.

Hope it can help you

XiangJun Rong

void DEMO_PowerDownWakeup(void)
{
BOARD_BootClockFRO12M();
BOARD_InitDebugConsole();
}