topic how to access FLASHBAR in ColdFire/68K Microcontrollers and Processors

how to access FLASHBAR

fire — Fri, 16 Jun 2006 12:36:10 GMT

Hai.

I amworking with MCF5282.In this how we can set FLASHBAR.

Actually internal memory is write protected by default.I want to change that bit.

how i can do that.

thanks in advance.

Re: how to access FLASHBAR

DavidS — Fri, 16 Jun 2006 22:49:46 GMT

Hi fire,

By definition flash is a write protected device that requires a flash programming algorythm to program/write to it.

Examples of flash routines on the ColdFire MCF5282/1/0 product web pages.

Specific ex: http://www.freescale.com/files/netcomm/software/app_software/code_examples/MCF5282SC.zip

Regards, DavidS

Re: how to access FLASHBAR

alexod — Tue, 05 Jun 2007 11:43:28 GMT

That was a nice example, but seems to address external flash. What about the internal flash in an MCF5213? The WP bit in FLASHBAR is a read only bit, and set at reset. How do I use the internal flash as non volatile memory? Do I need some magic pullups on the board? The only pertinent signals I could find would be TEST and RCON#.

I'm not talking re-flashing the firmware. I would like to know how to save user config there, same as I would on an external flash. This is especially important since I'm a low power app, and the battery backed SRAM is not implemented (correctly) on the MCF5213.

Thanks

Alex

Re: how to access FLASHBAR

mccPaul — Tue, 05 Jun 2007 15:09:41 GMT

Why do you think that the WP bit in FLASHBAR is read only? The dox I have seen (for 5216 and 5282) say it is write only (5282) or read/write (5216).

There are various write protect and security bits in the configuration register that are set on boot according to the values of various magic words in the flash. It took me some time to work out what the documentation was trying to say so I admit that it ain't simple!

Post back if you'd like to see an example for 5282, but I may not have time to post it until tomorrow.

Cheers,

Paul.