Change system clock frequency to 150MHZ

timmermans — Fri, 13 May 2022 14:49:32 GMT

I need my system clock to run on 150 MHz. But I also need to read&write to Flash.
To achieve this I wanted to change the clock from 150 MHz to 75 MHz and after the Flash operation bump the speed back up to 150 MHz.

But I am not sure how to do this.
I wanted to do is in the following way:

void System::decreaseMainClockSpeed()
{
CLOCK_SetClkDiv(kCLOCK_DivAhbClk, 2U, false);
POWER_SetVoltageForFreq(75000000);
SystemCoreClock = 75000000;
}

void System::resetMainClockToOriginalSpeed()
{
POWER_SetVoltageForFreq(150000000);
CLOCK_SetClkDiv(kCLOCK_DivAhbClk, 1U, false);
CLOCK_GetFreq(kCLOCK_BusClk);
SystemCoreClock = 150000000;
}

The decreaseMainClockSpeed function works like it should. But when I call the resetMainClockToOriginalSpeed everything breaks after the CLOCK_SetClkDiv(kCLOCK_DivAhbClk, 1U, false); function.

Can someone help me?

Re: Change system clock frequency to 150MHZ

Pavel_Hernandez — Mon, 16 May 2022 22:20:17 GMT

Hello,

I recommend the use of the MCU config tool, try to change the frequency and evaluate what changes were made in the code then implement them in your application.

LPC MicrocontrollersのトピックChange system clock frequency to 150MHZ

Change system clock frequency to 150MHZ

Re: Change system clock frequency to 150MHZ