LPC Microcontrollers中的主题 Re: Disable crp3 lpc2478

Disable crp3 lpc2478

alessandro_dipi — Tue, 24 Dec 2019 07:53:23 GMT

Hi everyone, how can I disable this level of protection and go to other levels also wanting NO_CRP to test and then go back to a level of protection? thanks for the support

Re: Disable crp3 lpc2478

xiangjun_rong — Thu, 02 Jan 2020 03:08:30 GMT

Hi, Alessandro,

Regarding your requirement, I do not think it is feasible to change the CRP level, after test has completed, restore the original CRP level, because the CRP level is valid only after power off and power on.

Pls refer to part in section 8. Code Read Protection (CRP) in UM10237 Reversion 04.

Important: any CRP change becomes effective only after the device has gone
through a power cycle.

It means that after you change the CRP value, it is not valid until you power off and power on.

The CRP purpose is to block the JTAG port even block bootloader so that invader can not read your code and data from flash or RAM.

Hope it can help you

XiangJun rong

Re: Disable crp3 lpc2478

alessandro_dipi — Thu, 02 Jan 2020 17:45:45 GMT

Instead I reply saying that I have disabled crp3 from bin file, now if I write the flash with jlink it does not lock even after a cycle of ignitions, so I can rewrite the flash as many times as I want

Re: Disable crp3 lpc2478

xiangjun_rong — Fri, 03 Jan 2020 09:45:30 GMT

Hi,Alessandro,,

I suppose that you do not write the CRP value to flash which is located at 0x000001FC,pls check it.

XiangJun Rong