8-bit Microcontrollers中的主题 Re: Flash Writing and Erasing for the MC9S08QG8

Flash Writing and Erasing for the MC9S08QG8

kdelbarba — Thu, 22 Jun 2006 23:10:48 GMT

I've read all the previous topics related to this and have not found one to help. Right now I'm trying to write single bytes to Flash and erase pages in flash. I've written a function that seems to work when using single step but if I just let it run the flash isn't written to or erased.

void WriteToFlash(char charinput, int address, short erase)
{
char *write;
int done;

write = (char * )address;

if (1 == FSTAT_FACCERR)
{
FSTAT_FACCERR = 0;
} // end if // clearing Error Field

while (0 == FSTAT_FCBEF)
{
feedCOP();
} // end while // FCBEF Command buffer empty flag 1 means it's empty

*write = charinput; // load into buffer address and char going to write

if (0 == erase) // write
{

FCMD = 0x20; // write one byte
} // end if
else
{
FCMD = 0x40; // erase page the byte would be in

} // end erase else

FSTAT_FCBEF = 1;

asm
{
MUL;
}

if (FSTAT_FACCERR == 1 | FSTAT_FPVIOL == 1)
{
SendMsg("Error!!!!!!");
}

FSTAT_FCBEF = 0;

} // end write to flash

Thanks,

Kdelbarba

Re: Flash Writing and Erasing for the MC9S08QG8

glork — Fri, 23 Jun 2006 07:13:18 GMT

Hello kdelbarba.
I think you need to run the page-erase and byte-write functions in ram because flash is disabled during the process (so your program can't run...).
Also, I don't see where you initialize the flash clock divider, etc.
Look up application notes regarding 'Do-on-stack' which is a freescale flash-write routine.
ron

Re: Flash Writing and Erasing for the MC9S08QG8

fire — Tue, 04 Jul 2006 16:55:40 GMT

i agree with you glork .We shouldrun the WRITE and ERASE code in RAM.

You have to copy the code to RAM and rin it.

Re: Flash Writing and Erasing for the MC9S08QG8

irob — Thu, 06 Jul 2006 00:06:23 GMT

kdelbarba coded:

if (FSTAT_FACCERR)
{
FSTAT_FACCERR = 0; // clearing Error Field
}

According to page 55:

FACCERR is cleared by writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect.

Re: Flash Writing and Erasing for the MC9S08QG8

irob — Thu, 06 Jul 2006 01:53:57 GMT

kdelbarba, have you seen this post? It's a great tech note with sample code on copying a function from flash to RAM and then running the function from RAM. Works nicely with your function.

Re: Flash Writing and Erasing for the MC9S08QG8

Bud — Wed, 12 Jul 2006 06:02:03 GMT

Irob,

You mentioned page 55 on this forum.. the question is.. what note/document are you accessing? I plan to implement a flash page erase function as part of my application using a gt16.

Bud

Re: Flash Writing and Erasing for the MC9S08QG8

irob — Wed, 12 Jul 2006 06:08:29 GMT

Sorry about that. I was referring to the MC9S08QG8 datasheet: LINK.