Hi
We have a board with 2 x C6657, each with 2 x MT41J256M16HA-125 DDR3 memories.
We have followed the TI guidelines with respect to the tracking of the PCB, matched track lengths etc, used the spreadsheets DDR3 PHY Calc v11.xlsx and DDR3 Register Calc v4.xlsx, and have a fully working board with extensively tested memory interfaces.
As with other TI processors we've used in the past, the DDR interface works much faster than that stated in the datasheets. In the case of our C6657 board, as we're using DDR1666 devices, we can actually run at this speed over the temperature range that we need (10 to 30C).
My question is, I know that running at 1666MT/s (833MHz) would not be guaranteed by TI, but is there also a reliability issue running at the full 1333MT/s speed limit, or should we reduce this?
