Good idea! Thank you.
Regarding the 10k Pullups to 1.8V. My guess is they were trying to terminate this bus and keep power low. It is certainly not ideal from a signal integrity perspective. Along with this there is another odd issue with this memory bus, the DDR clk 100 ohm termination resistor is located before the two DDR memories. This would typically be at the end of the pair. I'm not sure it is related however I have an issue with one of these 5125 tower boards where it is not stable when run at 0 degrees C. Basically Linux hangs in about 5 minutes.
This is reply of freescale.
"These are 10k weak pull-up resistors to fix logic level at negated state. They have no effect on the DDR functioning. You can omit them or provide Vtt termination. In the last case, the value should be selected according to results of simulation. For example, on MPC5121ADS board 200 Ohm Vtt termination is provided on MBA, MCS#, MRAS#, MCAS#, MWE# signals."
In the document, I find that the two USB part and the two FEC part are multiplexed, so if I want to use two USB port , two FEC port and LCD, it is impossible if I don't expand other parts. Am I right?
Retrieving data ...