Ex-Bit =1 in linker.cmd | Freescale DSPs

Technical discussions about Freescale (Motorola) DSPs (including the DSP56000, DSP56300, DSP56600, 56800 DSPs).

Hello, I'm trying to build a stand-alone application that processes a lot of data that has to be stored in external data memory. I plan on using about 4MB of external data memory by expanding the 16bit address space with 5 GPIOs. My problem is that I do not understand how to setup the linker.cmd file for this. At the moment I'm programming the DSP56F807EVM with CW 5.2 and SDK 3.0. As I understand the ExtRam-Target is only for development purposes and not what I'm looking for anyway since I want my program to be located in internal memory. As for the Flash-Target I see that there is a ExRam segment but I want to use the whole of the 64k adress-space and not only what is left after stack, peripherals etc. have been allocated. I guess I can solve this problem by setting the Ex-Bit in the OMR- register in order to access the entire 64k of external memory. Does this mean that I have to change the EX-Bit all the time when I want to upload this data to the PC? - in order to upload the data from external data memory to the PC do I really need to read every single word into a ALU-register, change the Ex-Bit to 0 and then write it to the on-chip peripheral memory for the SCI? - could anybody send or post a linker.cmd file where EX-Bit=1? in all the linker.cmd files I have seen the EX-Bit is always = 0 - is there a SDK function that I can use to access external memory I appreciate any comments or examples of how to do this. Thanks hans

(You need to be a member of motoroladsp -- send a blank email to motoroladsp-subscribe@yahoogroups.com )

Sign in

Search motoroladsp

Subscribe to motoroladsp

motoroladsp by Keywords

Discussion Groups

Discussion Groups | Freescale DSPs | Ex-Bit =1 in linker.cmd

Ex-Bit =1 in linker.cmd - horba77 - Jul 30 12:26:00 2003