Hi to all,
I am facing a problem with my newly designed board specially on PHY IC(DP83848C) and few GPIO's. I am using LPC2388.
I received a new version of hardware which has all hardware's placed are same as previous board at least for Ethernet circuit. In my previous version of board all parts are working well.
With my new board i tried to write and read the Phy registers. I succeed on reading and writing to the Phy registers. But its always saying Link is broken and not available.
My speed LED is always high. When i connect RJ45 with my board no Link lED nor Ack LED is blinking. I would like to know what are the Ways available to debug my board specially on Ethernet circuit?
I would like to know what are the Debugging methods are mandatory and available to check a Phy IC whether its communicating with my Controller as well as to the network. I checked all the possible hardware connections. All are connected well.
If you face this kind of problem what you will do to diagnose the problem?
Please ask me if you are not clear at any point.
Thanks for your reply.
When i read the Link register when actually a link was presented, the return value of PHY said that there is no link. In the Init_ethernet(), before checking the Link status my LPC_EMAC.c code puts the PHY to Autonegotiation mode. But if read the PHY its not able to complete the Autonegotiation complete.
So i believe problem starts here. The document says the status of three LEDs at Reset/power-Up indicates the status of the ANAR reg. So is my PHY IC is not coming out of reset mode?
Link status bit in BMSR is defined by IEEE 802.3u Clause 22. It indicates if the link was lost since the last time this register was read. Its name (given by IEEE) is perhaps misleading. A more accurate name would have been the “Link lost” bit. If the actual present link status is desired, then either this register should be read twice or depending on the PHY, read the PHYSTS (0x10 bit 0 for 83848) register.