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STM32F4DIS-BB ethernet clock problem

Question asked by donchev.petar on Jan 12, 2015
I just want to share one solution for a problem which I found on the expansion board STM32F4DIS-BB. I'm developing application which need high ethernet throughput, but faced a problem with many damaged rx frames (with bad CRC). I was sure, that this is probably a hardware problem and looked at the board schematic. What drew my attention was resistor R27 (220 Ohm) on the reference clock between PHY and MCU. I suspect that its value was intended to be 22 Ohm, but for some reason it is 220 Ohm. After shorting it the problem
disappeared. Not a single bad frame and the communication is now smooth and fast.