lpcware

LPC4357 (with LPCOpen): Splitting code between off-chip ROM and on-chip IROM

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by AlexMSmithCA on Thu Jun 05 00:47:22 MST 2014
Hi,

I have been looking around and haven't found an answer that I was able to use.  I have a monolithic piece of code (web pages stored as byte code in an array) that I want to off-load to a 4MB external flash chip (SPIFI) since it does not fit within the two 512kB on-chip flash.  I'm using uVision 4 and right now I have it set up so that the on-chip IROM1 is my start-up location, and I just try to shift over the web code to the ROM1 off-chip memory.  When I run it, I get "Cannot access memory" and it seems that all of the off-chip memory cannot be accessed.

I have not worked with embedded devices too much, and am not sure if this is a clocking issue, or if the code can only be stored in one block of memory, or what it might be.

If I put everything within the off-chip memory the program runs fine, albeit slower.  If I put it all on the on-chip memory (minus the web pages), it also works fine.  It seems only when I try to split the code between the two I run into issues.

Any help is greatly appreciated!  I can also provide more information, just tell me where to look.

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