LPC5528 Simple CRP enable/disable

[bressan]

I want to write a simple code read protection for LPC5528, which can be enabled/disabled via USB.

Until now, I have only LPC55S28.

Afraid of bricking the device, I tried writing in customer area first.

I tried writing on a LPC55S28 via FFR this way:

DisableIRQ(); setcpu100MHz();
Status = FLASH_Init(&flashInstance); //returns 0
Status = FFR_Init(&flashInstance);  //returns 0=ok
FLASH_GetProperty(&flashInstance, kFLASH_PropertyPflashPageSize, &PflashPageSize);

Status = FFR_InfieldPageWrite(&flashInstance, iap_FlashRam, len);
//returns 0x64. why?

iap_flashram contains a copy of the 0x09df00 region with modified data at offset 0x100. len is 32 bytes.

[bressan]

For all users, which want to implement simple CRP (Code Read Protection) for LPC55xx / LPC55Sxx:

Disable debug, and fully read protection: CMPA cc_socu_pin / cc_socu_dflt to 0xFC0003FF / 0xFFFF0000

Reenable debug: CMPA cc_socu_pin / cc_socu_dflt to 0/0 and CFPA set all 0 and increase version.

[Alice_Yang · Accepted solution]

Hello Bressan,

Yes, the length must equal the page size.

There may be different length for other part flash page.

BR

Alice

[bressan]

I was able to write, if len==0x200.
It seems, like I must write the full page at once. So, why is there a parameter for the length?