topic Xgate on Flash in S12 / MagniV Microcontrollers

Xgate on Flash

RubenCG — Wed, 25 Apr 2007 15:37:49 GMT

Hi,
I'm working with mc9s12xdp512 16-bit proccessor. This MCU has Xgate co-processor. Xgate is a great idea for the purpouse of my application but I have some questions that, perphaps, you can resolve.

Is it possible to execute Xgate code from Flash or is it a must the code was executed from RAM?

Thanks in advance
Ruben

Re: Xgate on Flash

Steve — Wed, 25 Apr 2007 19:06:00 GMT

XGATE has access to about 30k of flash and you can use this for whatever purpose you want including code space.

Be aware that XGATE will run at half the speed when fetching code from flash (i.e. same bus speed as the CPU - 40MHz max.) and this is the reason that RAM is the primary recommendation. Essentially flash is slow compared to RAM.

To place XGATE code in RAM you define the appropriate code segment in the linker file and the linker will place the code where you want it to be.

Re: Xgate on Flash

RubenCG — Wed, 25 Apr 2007 20:18:10 GMT

Thank you Steve for your quickly answer. Now I know that I have the two possibilities, probably I'll use the RAM.