Serkan Erdogan wrote: > I need to reduce dm355 pll and ddr ram speed and adjust ddr2 ram parameters > (CAS and Reading Latency etc. ) to make it suitable for my mainboard layout, > but i could not find initialization code for this hardware modules in kernel > tree.
I can only speak for DM644x, but these systems need to be initialized by the initial bootload (TI UBL) before any other code is run. > Please say me where and what to change? Is there any possiblity for > that uboot does all PLL and DRAM initialization and linux kernel doesn't > touch it again? If this is true my job is more clear and easy but i need > help... Well, I think you can change the PLL from u-boot, but the SDRAM settings are definitely done inside the TI UBL code. For the DM644x, we use the "Flash & Boot Utils" package from TI. I think they're all very similar, so if you get that package for DM355 and look in <install_dir>/Common/src/device.c you should see constants for SDRAM timing. We did switch chips from the ones that were on the EVM and I had to use the ram datasheet to modify these timing constants for our custom board... the hardest part is figuring out the manufacturer's abbreviations for the constants. Unfortunately, I can't tell you what those constants need to be, you'll have to consult your ram datasheet for that. Hope this helps out, David -- DAVID A. KONDRAD Software Design Engineer Legrand Home Systems Division http://www.legrand.us/onq This email, and any document attached hereto, may contain confidential and/or privileged information. If you are not the intended recipient (or have received this email in error) please notify the sender immediately and destroy this email. Any unauthorized, direct or indirect, copying, disclosure, distribution or other use of the material or parts thereof is strictly forbidden. _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
