ml310 DDR problem

In our lab we have a number of ml310s and use them for both PPC and MicroBlaze designs. For the PPC designs using the external DDR SDRAM that came with the board we experience no issues.

However, the DDR when used with the MicroBlaze does not initially function correctly upon configuration and has to be reset using the CPU reset button, after which it works fine until the next configuration. This is true even for designs using the default BSB MicroBlaze design for the board.

Upon initial configuration, MicroBlaze programs as well as XMD return junk when reading from the memory and the MicroBlaze will sometimes hang on write attempts, more so it seems at lower operating frequencies. The garbage read from the memory appears to vary slightly between consecutive reads.

Again, everything works fine after a reset or two.

Does anyone have any idea what could be causing this?

Thank you in advance, Stephen

Reply to
Stephen Craven
Loading thread data ...

There is an implementation note in the XBD files for the ML310, which says among other things that a minimum clock frequency of 66MHz is required for the DDR parts on this board. It also has a reference to Answer Record 19385. Might be worth a look.

Cheers,

John

Reply to
John Williams

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.