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Altera_Forum's avatar
Altera_Forum
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16 years ago

question about __attribute__

There are two memory section in my Nios system, one external chip SDRAM and another onchip memory:a 16K byte ram which is generated by the SOPC tool. Our project need to put one function code in the ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Hello,

How are your code sections being initialised? It may be that your on-chip memory has not been loaded. In my system I use flash to store the code images, which are then loaded into RAM by the bootloader at startup. My main code is loaded into an external RAM and I have an ISR which is loaded into on-chip RAM (specified using the __attribute__ keyword as you have described).

I'm not 100% sure, but your setup may require you to re-compile your Quartus project (or update RAM contents at least) so that your on-chip RAM is initialised by the FPGA configuration. You should find that the IDE has created a file called onchip_mem.hex in your hardware folder which is used to set the initial contents of your on-chip RAM.

I hope this helps.

Cheers