Flash Unprotect

[bender]

Posted on August 31, 2006 at 05:38

Flash Unprotect

[bender]

Posted on August 30, 2006 at 14:04

Is anyone else having problems unprotecting flash?

I am using the Keil MCBSTR7 Evaluation board and am having the following problem:

If I add the following code at the start of the main function the only way I can get the chip to boot is to start it using the ULINK JATAG debugger.

I have narrowed it down to the register write that starts the flash controller, writing a one to

Bit 31 of the Flash Controller Register “DR0”. If I reset the board without the JATAG debugger running and then break into the system using the debugger the Undefined_Handler() function is constantly being called and the processor Mode is “Undefined”.

This problem also occurs on an OUMEX development board, so it is not a board problem.

Main()

{

//

// Initialize the FLASH

//

FLASH_Init () ;

FLASH_WaitForLastTask();

/* Set the Set protection Bit */

pFLASHR->CR0 |= FLASH_SPR_Mask;

/* Set the Register Address */

pFLASHR->AR = 0x4010DFB0;

/* Data to be programmed to the Protection Register */

pFLASHR->DR0 = FLASHPR->NVWPAR|FLASH_B1F1;

/* Set the WMS bit to Start the Sequence */

pFLASHR->CR0; |= FLASH_WMS_Mask

}