Hi,
We are debugging a system equipped with p2020 processor and micron MT47H64M16HR DDR2 memories. Unfortunately we can't get u-boot loading correctly to the DDR. We've managed to get u-boot loaded to the L2 cache and to put our own DDR debugging code into the board initialization code (namely into board specific ddr.c file). It seems, that the DDR is not initialized properly by standard u-boot DDR2 parameters for P1_P2_RDB board.
We've analyzed thoroughly the datasheet:
formatting link
and we've found that the required initialization procedure (see pp.
86-88 in the datasheet) is quite complicated. The p2020 contains a versatile DDR controller, but it seems to be unable to perform e.g. multiple loading of the MR register (first with DLL reset command as required in step 8, and then without that command as required in step 11).
So my question is:
- Has anybody managed to force the internal P2020 DDR controller to succesfully initialize this memory?
- Has anybody prepared the DDR initialization data for boot_format, so that P2020 on-chip loader is able to initialize this memory executing the configuration data form the SD card? (In fact this seems to be necessary, as before the DDR is initialized we are not able to load the u-boot! We were not able to build correctly working L2 cache loaded u-boot for P2020 :-( ).
- Has anybody implemented the initialization procedure for that memory for u-boot?
-- TIA & Regards, Wojtek