DS110DF111: Using a DS110DF111 to convert a 10GBASE-KR interface to a SFI interface of a SFP+ module for a 10GBASE-SR application

Hi,

Harold Steger said:

I'm trying to understand the relationship between the 10GBASE-KR signals and protocols and how to convert that interface to the SFI interface (electrical) of a SFP+ optical transceiver of a 10GBASE-SR interface.  I believe TI's DS110DF111 can be used in this media converter application but I'd like to understand the relationship between these two interfaces.

I suggest reading Clause 72 (Physical Medium Dependent sublayer and baseband medium, type 10GBASE-KR) and Clause 52 (Physical Medium Dependent (PMD) sublayer and baseband medium, type 10GBASE-S (short wavelength serial), 10GBASE-L (long wavelength serial), and 10GBASE-E (extra long wavelength serial)) of the IEEE802.3 standard. These sections should provide more details about these protocols.

Additionally we have some application notes which discuss using 10G retimers in 10GBASE-SR applicaitons.

https://www.ti.com/lit/an/snla225/snla225.pdf?ts=1701284097814&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDS110DF111

https://www.ti.com/lit/an/snla325/snla325.pdf?ts=1701287815054&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDS110DF410

One key thing to note is that link training should be disabled on the 10GBASE-KR side. Our retimers are protocol unaware and do not support link training. If link training is required, then I suggest using one of our 10G redrivers instead.

Harold Steger said:

Are there any restrictions or special conditions required to interface the Ice Lake's 10GBASE-KR interface to the DS110DF111 for this 10Gb SFI connection?

Make sure to disable link training.

Harold Steger said:

Does this interface need to support CEI (Common Electrical I/O interface)? 

Our retimers adhere to IEEE802.3 and OIF-CEI standards.

Harold Steger said:

I've read that some applications require PHY-specific files programmed into the EEPROM that interfaces to the DS110DF111.  Is that the case for this application?

It's your decision whether you want to program the DS110DF111 with an EEPROM or an SMBus controller.

Best,

Lucas