8-bit MicrocontrollersのトピックVariable initialization in EEPROM at Compile Time

Variable initialization in EEPROM at Compile Time

belskyc — Sat, 06 Feb 2010 04:55:13 GMT

Hello,

I'm a user of the 8-bit HCS08 microprocessors (in this project I'm using the HCS08DZ60A). Does anyone know of a technique where I can initialize a variable that's declared in EEPROM at compile time? In other words, I'd like to do something like the following:

#pragma DATA_SEG _EEPROM
// Variable initialized during compile.
volatile unsigned char eeprom_byte = 0xAB;

So that after programming the microprocessor, the variable eeprom_byte is initialized to value 0xAB.

What I'm trying to accomplish is a method for detecting a 'virgin load' of the firmware into the micro, and store the status in this byte.

Thanks much,

~Chris

Re: Variable initialization in EEPROM at Compile Time

ok2ucx — Sat, 06 Feb 2010 06:09:03 GMT

Chris,

looks like that accidentally the same question has already been answered in the following thread: http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&thread.id=15738

Hope this helps you,

Pavel

Re: Variable initialization in EEPROM at Compile Time

CompilerGuru — Sat, 06 Feb 2010 08:15:07 GMT

Note that the key is that the segment used in the prm file must be using the READ_ONLY type,

not that the variable is const. I would actually make the variable const as the varible is not writable with a simple write, but as far as the tools are concerned they do not insist.

Everything in a READ_ONLY segment gets programmed at download time, everything in a READ_WRITE segment gets initialized during program startup (and everything in a NO_INIT or PAGED segment does not get initialized automatically at all).

Daniel