Hi, we have built our design based on the 52259EVB from Freescale, but unfortunately we can not get the 83640 PHY from National to report ethernet link. This problem is probably not realted to uTasker, but any help would be appreciated.
We have built three prototypes with similar results:
a. No ethernet link at all in 100Mb mode.
b. If we force 10Mb mode by writing to the 0x0 register in the PHY and force the PC's network card to 10BaseT, the pc reports link, but our design doesnt.
c. We checked straps, reset and clock (25mhz) to be ok in the 83640.
d. We compared waveforms in our design and in the EBV and found that TX_CLK and RX_CLK signals in the 83640 are 50mhz with lots of jitter instead of the 25 Mhz required for the part to run in 100Mb mode. Also in 10Mb mode, frequency is 5Mhz instead of 2.5Mhz
e. The normal Link pulse sent every 16ms is 50ns instead of 100.
f. We compared all the 83640 registers in our design with the registers in a running EBV board, and the contents are identical!
We tried several prototypes with and without the 82259 installed and observed similar results. We were wondering if anybody designed based on the 82259 EVB board and had similar problems, or maybe can suggest an approach for debugging this problem.
Thanks for your time
Elio Mussini