I would like to use the DP83910A, but it's 10MBps bit rate is a little high for my application. I thought about using a 2MHz external clock instead of a 20MHz clock oscillator, but I'm not sure how flexible the chip's PLL is with different clocks. Please advise me on whether it is possible to reduce the chip's clock rate as I have described, or if there are other ways I could go about it.