S12 / MagniV MicrocontrollersのトピックRe: How can I place an array of constants in program memory?

How can I place an array of constants in program memory?

Mel1949 — Tue, 21 Mar 2006 00:16:14 GMT

DSP56F805 (DSP56800 series)

CW 5.6.1.1658 - DSP56800-R7.0

I need to move a "large" (2k) array out of data memory and place it in program memory. In the DSP56800E version there is a __pmem modifier to cause variables to be place in program memory but this is unavailable on the 56800 version. Could I use inline asm code and org it P the create the array. If so, how do I reference a variable created in assembly from the main program?

Re: How can I place an array of constants in program memory?

imajeff — Tue, 21 Mar 2006 05:58:56 GMT

It seems to me that you can declare a const variable, which would go into flash in the section (or whatever it's called in CW) for read-only data (I call ".rodata"). If needed, you would use pragma to direct it to any other section.

Re: How can I place an array of constants in program memory?

Mel1949 — Wed, 22 Mar 2006 02:38:56 GMT

Thanks Jeff

I was getting a linker error Segment Overflow with the pRom-xRam target. Changed target to xRom-xRam and it links fine.

Re: How can I place an array of constants in program memory?

glenn_calmotion — Thu, 28 Feb 2008 01:37:56 GMT

We have a similar problem but we have arrays that are 16K+ in total size. The linker wants to move this array into data flash or data ram but there isn't enough space.

We just want to keep all of our arrays in program flash and access it there since there is 128K flash there. Nothing works, constants, __pmem, making our own memory sections...

Anyone have the answer to this simple need?