Part Number: DP83848J
Hi,
I am using an Arty board (Digilent) and trying to communicate with DP83848JSQ from an FPGA.
I am able to communicate with the Ethernet PHY via MDIO interface and read the vendor ID and other status registers.
Now After reset release , when I plug the RJ45 jack of Arty board to PC the link up status remain low. I have tried reading BMSR register . Here the link up bit remains low.
I guess the device is in default state as i have not initiated any configuration.
i was expecting Link detection OK if I plug into a PC.
Below is the reading I obtained from PHY when unconnected and connected to PC. I guess PC cable is straight . At PC side auto-negotiation is enabled.
| Register ADDR | REG NAME | Content (RJ45 unconnected) | Content (RJ45 Connected to PC) |
| 0000h | BMCR | 3100h | 3100h |
| 0001h | BMSR | 7849h | 7849h |
| 0002h | PHYIDR1 | 2000h | 2000h |
| 0003h | PHYIDR2 | 5C90h | 5C90h |
| 0004h | ANAR | 01E1h | 01E1h |
| 0005h | ANLPAR | 0000h | 0000h |
| 0006h | ANER | 0004h | 0004h |
| 0007h | ANNPTR | 2001h | 2001h |
| 0008h | 0000h | 0000h | |
| 0009h-000Fh | Reserved | ||
| 0010h | PHYSTS | 0000h | 0000h |
| 0011h-0013h | Reserved | ||
| 0014h | FCSCR | 0000h | 0000h |
| 0015h | RECR | 0000h | 0000h |
| 0016h | PCSR | 0100h | 0100h |
| 0017h | RBR | 0001h | 0001h |
| 0018h | LEDCR | 0000h | 0000h |
| 0019h | PHYCR | 8001h | 8001h |
| 001Ah | 10BT_ SCR | 0804h | 0804h |
| 001Bh | CDCTRL1 | 0000h | 0000h |
| 001Ch | Reserved | ||
| 001Dh | EDCR | 6011h | 6011h |
What could be the issue?? Do I need to do some configuration for Link status detect.
