DP83TD510E-EVM: How to implement the 10BASE T1L function

Hi, 

Lumina Gui said:

1) Is there a requirement for internal/external delay in RGMII timing?

Timing requirements for RGMII are listed in section 5.6 of the datasheet

Lumina Gui said:

2) Does the main control/bridge chip come with TXC delay? What are the precautions for Layout?

The PHY comes with the ability to tune both RX and TX Clock to ensure the timing requirements are met. This setting is found under register 0x17. For the layout, we want to make sure that the impedance of the line is 50 Ohms and that the lines are all length matched

Lumina Gui said:

What kind of SPE transformer/isolation is used? Is there any recommended model?

Depending on the application, the customer can use different circuits on the MDI side. An overview of this can be found in section 7 of the datasheet. Generally, we use capacitors for isolation

Lumina Gui said:

4) After power on, the default is 10BASE-T1L, or does it need to be configured?

This device is only capable of 10Base-T1L so it is the only mode it can operate in. Settings such as voltage level on MDI side, RMII/RGMII interfaces, etc. can be configured through registers.

Lumina Gui said:

1) Is there a case of using DP83TD510E on Linux 4.9? We have noticed that TI's official driver is from 2020, which is the Linux 5.4+kernel.

Unfortunately, we have not used linux 4.9. You would need to port it using the 5.4 version driver (and maybe some generic 4.9 version PHY driver).

Lumina Gui said:

2) Does the 10BASE T1L protocol completed internally? or does it require additional support from the kernel, such as some network protocols. Are there any requirements for the kernel version?

Device configuration and use as a network interface should be unaffected even in 4.9, but certain generic utilities may be affected, such as ethtool.

Best,

Vivaan

Hi，Vivaan

We would like to consult about the feasibility of the following Ethernet architecture:

1. Is it possible to use the USB interface of the Amlogic S905D2, convert it to MII, and then connect it to DP83TD510E (10BASE-T1L PHY)?

The reason is that the on-chip Ethernet MAC of the host is currently occupied by RTL8211, so we are exploring alternative interfaces.

2. Alternatively, is it feasible to use a USB-to-RJ45 solution with an RGMII PHY (such as DP83822), and then connect that to DP83TD510E?

Could you please advise whether either of these solutions is technically viable, and if there are any recommended reference designs or constraints we should be aware of?

Hi Zihao, 

Zihao Chen said:

Is it possible to use the USB interface of the Amlogic S905D2, convert it to MII, and then connect it to DP83TD510E (10BASE-T1L PHY)?

Yes, you can utilize a USB to MII converter device to achieve this functionality.

Zihao Chen said:

Alternatively, is it feasible to use a USB-to-RJ45 solution with an RGMII PHY (such as DP83822), and then connect that to DP83TD510E?

Is this referring to the Green part in the picture provided? You could simply use the RGMII interface on the 510 instead of using an 822.

Best,

Vivaan