On 7/1/2013 12:56 AM, Claudius Zingerli wrote:
...This may further be related to the usage of RMII between the MAC and PHY and creating the RMII-Clock with the STM32-PLL. Datasheet jitter and precision should be OK for the PHY, but this might not be the cleanest solution (There is some hint in the datasheet that good guys should source the RMII clock by bypassing the PLL). So in a next step, I'm going to use a dedicated 50MHz oscillator to clock the PHY and MCU.
This is a known issue. Deriving the RMII-Clock with the STM32-PLL is just not a robust design.
There are several PHY chips (Micrel, etc) that have built in RMII clock generators that can use a low cost 25MHz crystal and provide a nice low jitter clock back to the MCU.
-- Later, Jeff _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users