Dear TI team,
I'm not an electrical engineer so please bear with me. Also, I would be UNABLE to share any schematic or any other confidential information.
We are using DP83TC812S-Q1 PHY interfacing with one of the port on managed switch.
During our initial development I'm using EVB-LAN8770M_MC boards to test the operation modes master/slave.
I'm trying to troubleshoot following two problems,
- When the PHY is in slave mode and the MC in master mode, the MC D4 Link LED along with the switch port NEVER detect the active link.
- When the PHY is in master mode and the MC in slave mode, FOLLOWIGN A POWER RESET OF DEVICE (WHOLE BOX INCLUDING SWITCH AND PHYs), the MC D4 Link LED along with the switch port takes hours before detecting the active link.
Following is what I've tried already,
- Using two MCs, one as master and other slave, the D4 Link LED show GREEN following SW1RESET of both boards. Changing the MC operation mode also works and show D4 Link LED GREEN following SW1RESET.
- When the PHY is master, MC is slave and the D4 Link LED is already GREEN (when it clears the problem 2 above), I could change the 0x1834 register to put PHY in slave mode (0x8000) and immediately to master mode (0xC000). The connected MC D4 Link LED immediately changes the state accordingly i.e. Green when PHY is master, when PHY is slave it stay OFF.
- Do hard/soft reset by changing the 0x1F register but that didn't help with any problem.
- Change the managed mode (0x1c4b) to autonomous mode (0x1c0b) by changing 0x18B register but that also didn't help. BTW, the is no details about 0x18B on datasheet.
- Disable the auto-negotiation (0x027a) by changing 0x608 register with no success.
Other important points, looking at the schematic.
- The PHY LED_0 is put in master mode by-default.
- The PHY LED_1 is put in managed mode by-default.
Is there anything else that I have missed, and I could check?
Thx for help,
