topic Re: fsl_iap Erase/Program checks clock in 25.6 in LPC Microcontrollers

fsl_iap Erase/Program checks clock in 25.6

Folkert — Mon, 22 Sep 2025 09:03:42 GMT

With an update of the fsl-library to 25.6, I noticed that in fsl_iap.c the erase and program functions have a check on the clock being higher than 100MHz.

Here the kCLOCK_CoreSysClk is checked, which is the main_clk in fig 4 in UM11126, page 43. I think this should be checked against kCLOCK_BusClk, which is the actual clock to the CPU.

Kind regards,

Folkert

Re: fsl_iap Erase/Program checks clock in 25.6

Harry_Zhang — Tue, 23 Sep 2025 10:25:52 GMT

Hi @Folkert

I checked this demo.

I found that

CLOCK_SetClkDiv(kCLOCK_DivAhbClk, 1U, false);

So the kCLOCK_BusClk is the same with the kCLOCK_CoreSysClk.

And i print them. they are same.

You can tested it.

Harry

Re: fsl_iap Erase/Program checks clock in 25.6

Folkert — Wed, 24 Sep 2025 09:39:55 GMT

Dear @Harry_Zhang

Thank you for your answer.

We use the LPC55S69 with the clock connected to PLL0, which runs at 150MHz and normally, we have kCLOCK_DivAhbClk set to 1. When we want to write to flash, we set kCLOCK_DivAhbClk to 2 to have the CPU running at 75MHz, which is functional.
In this case, the fsl_iap functions should check on kCLOCK_BusClk, because then it differs from kCLOCK_CoreSysClk.

Kind regards,

Folkert

Re: fsl_iap Erase/Program checks clock in 25.6

Harry_Zhang — Thu, 25 Sep 2025 06:21:23 GMT

Hi @Folkert

Yes, you are right.

When we set kCLOCK_DivAhbClk to 2,

the fsl_iap functions should check on kCLOCK_BusClk.

Harry