IAP call crashes when trying to read UID

[koen2]

I am using the LPCOpen library at the moment with MCU LPCExpresso IDE for  the LPC1830 chip.

For a project I need to read the UID of the CPU. I tried it with the following functions:

But it crashes and I don't know why. Maybe someone can help me?

I increased the cpuUID size to 5, but 4 is enough.

Program counter has weird number: 0x12345678 

uint32_t cpuUID[5] = {0};
 Chip_IAP_ReadUID(&cpuUID[0]);

//The function call crashed on this function:

/* Read the unique ID */
uint32_t Chip_IAP_ReadUID(uint32_t uid[])
{
 uint32_t command[5], result[5], i;

 command[0] = IAP_READ_UID_CMD;
//CRASH
 iap_entry(command, result); //IAP ENTRY CRASH

 for(i = 0; i < 4; i++) {
 uid[i] = result[i + 1];
 }

 return result[0];
}


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Note in this picuture: uint32 needs to be uint32_t (line 103)

[koen2]

Thanks for you answer Bernhard. After searching in the datasheet I found the same information. 

To fix this issue I used the following code to just read the UID of the CPU:

Chip_OTP_Init(); //located in  "otp_18xx_43xx.h"
unsigned char buf[16];
uint32_t * pntrID = (uint32_t *) 0x40045000; 

memcpy(buf,pntrID,16); //this will copy from memory location 0x40045000 16 bytes into an buffer. Containing the UID.

//DumpHex(buf,16,"UUID"); //own function


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[bernhardfink · Accepted solution]

IAP is intended to deal with an internal flash. There would be commands like ReadUID which do not work directly on the flash, however it is a restriction in the flashless parts of LPC1800 and LPC4300.

See error sheet, chapter 3.4

https://www.nxp.com/docs/en/errata/ES_LPC18X0.pdf 

Regards,

Bernhard.