Hi, I'm designing a data logger that samples at a given interval. This interval is user-set, so I want it to be recalled when the devices is reset or after power-down. I imagine I would do this by writing a byte to ROM, and then reading it upon bootup. How can I do this? 

Thank you,

b

Normally the ROM is not writable (ROM = Read Only Memory) but you'll find an EPROM usermodule which allows you to store data whivh will be kept between power-offs.

Have a look into its datasheet to find out how to use it.

Bob

 Got it. Thank you! Now I have a new problem though. EEPROM seems to write to memory fine. I have 2K of EEPROM on my chip, so I write some parameters to row 126, which is towards the end. Then I try to read from it and store it in an array.

uint8 romParamaters[SIZEOF_EEPROM_ROW];

reg8 * RegPointer = (reg8 *) (126*CYDEV_EEPROM_ROW_SIZE + CYDEV_EE_BASE);

uint16 i = 0;

    for(i=0u;i<CYDEV_EEPROM_ROW_SIZE;i++){

        romParamaters[i] = RegPointer[i];

}

If I put a breakpoint at the for loop, I see that the EEPROM wrote the right data to memory. The next line, where I do the assignment, crashes however. Not sure why. Any clues? Thanks again.

b

When you turn off optimization for your project and rebuild it, debugging will work, I cannot see any error in your code.

Bob

I assume when you stated write to ROM you meant FLASH.

Seems like your project lends itself to EEPROM, but if you find yourself needing

more storage than the 2KB you can also write to FLASH. Number erase cycles drops

from 1,000,000 to 100,000 however.

Regardsm Dana.

 Hi Dana - Thank your for your help. This is still not workign for me. It's driving me absolutely crazy. I put a breakpoint before I do the assignment to my local array from EEPROM. I have a pointer to memory:

uint8 * RegPointer = (uint8 *) (STARTING_PARAMETER_ROW*CYDEV_EEPROM_ROW_SIZE + CYDEV_EE_BASE)

I break, and can see the contents of memory in the debugger. Everything looks right, until I try to read from these addresses. Then thigns crash completely and the debugger freezes. Where do I turn off optimization? Looks like GCC is aloready not using it in build settings. Any help would be appreciated. Basically, reading from ROM is crashing my stuff. 

thanks!

 Sorry, but I figured it out. I never wrote a fully initilized 16 bytes to EEPROM at once. Once I wrote a full array, it worked. Thanks!

 I take it back. It's doing it again. Jsut plain freezing. I'm back to taking advice. thanks