Author Topic: TE0720 Ethernet interface questions for custom carrier board  (Read 2022 times)

joseer

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TE0720 Ethernet interface questions for custom carrier board
« on: January 07, 2018, 08:18:05 PM »
Hello,

I'm working in a  custom carrier board for TE0720. I've got the TE0703 carrier and I'm using it as a main reference. I've got a couple of questions about the Ethernet interface side:

1. In the TE0703 carrier board the ETH-VCC signal of the JB1 connector is connected to the gigabit RJ45 jack pin 1 but at the TE0720 side the same pin (PHY_COM) is not connected, so the RJ45 magnetics are not powered? is it an error in the schematic? if not, why it is like that?

2. For another side in my design I don't need to work with the gigabit capabilities of the TE0720 board with 10/100 Ethernet will be enough, and I'm planning to connect this board: https://www.proto-pic.co.uk/sparkfun-rj45-magjack-breakout.html with this RJ45 Fast Ethernet mag jack: https://www.sparkfun.com/datasheets/Prototyping/MagJack.pdf

Do you know if the Ethernet interface (for 10/100) will work doing the next connections?:

PHY_MDI0_P --> P1
PHY_MDI0_N --> P2
ETH-VCC       --> P3
NC                --> P4
NC                --> P5
ETH-VCC       --> P6
PHY_MDI1_P --> P7
PHY_MDI1_N --> P8

Thanks in advance.

Vadim Yunitsky

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Re: TE0720 Ethernet interface questions for custom carrier board
« Reply #1 on: January 10, 2018, 12:05:31 PM »
Hello joseer,

1. Marvel Alaska 88E1512 PHY Evaluation Board describe the same connection when transformer mid-point connected to ground via capacitor. It works in all 10/100/1000Mbps Modes.

2. 88E1512 PHY allow to operate in 10/100 Mbps modes (100BASE-TX and 10BASE-T standards) using 2 lanes instead of 4. As I know our engineers use 4-lanes for all modes and didn't test 2-lane connection.

Standard pin positions are 1,2,3,6 (PHY_MDI0 and PHY_MDI1), others are not used.
You use correct lanes but non-standard RJ45 connection. Also I don't know a reason why you need to connect ETH-VCC to  P3 and P6.

You could try to test connection using external loopback option.

joseer

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Re: TE0720 Ethernet interface questions for custom carrier board
« Reply #2 on: January 10, 2018, 06:36:59 PM »
Hi Vadim,

Thanks for the answers.

Looking at the RJ45 jack's schematic (page 2) that I'm using: https://www.sparkfun.com/datasheets/Prototyping/MagJack.pdf , the transformers mid-points are P3 and P6, so I connected both to the TE0720 ETH-VCC signal, given the previous datasheet, do you think that should it be connected in another way?

« Last Edit: January 10, 2018, 06:38:34 PM by joseer »

Vadim Yunitsky

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Re: TE0720 Ethernet interface questions for custom carrier board
« Reply #3 on: January 11, 2018, 04:40:02 PM »
Joseer,

I didn't realize that you are talking about 10/100BASE RJ45 jack.

According to Ethernet PHY Alaska 88E1512 Evaluation Board schematic I offer you to connect P3 and P6 mid-point to ground via capacitor and also connect to pin ETH-VCC (like in our design TE0703), but it's not mandatory.

Some other PHYs (like Marvel 88E1111 or from Microchip) require connection of mid-point to VCC.
ETH-VCC pin was reserved on base board to have opportunity to use some other module with different 100Mbps Ethernet PHY (for example TE0600).

Here you could find our other base board TEB0729 (for module TE0729) with 1x 1000Mbps (88E1512-A0-NNP2I000) and 2x 100Mbps (KSZ8081MLXCA) Ethernet PHYs.
Baseboard TE0729 - https://shop.trenz-electronic.de/de/TEB0729-03A-Traegerboard-fuer-TE0729-Zynq-7020-SoC-mit-USB-A-Host-Connector?path=Trenz_Electronic/carrier_boards/TEB0729/REV03/Documents
Module TE0729 - http://www.trenz-electronic.de/fileadmin/docs/Trenz_Electronic/TE0729/REV02/Documents/SCH-TE0729-02-2IF.PDF

or TE0600 with PHY 88E1111-B2-NDC2I000

Module TE0600 - http://www.trenz-electronic.de/fileadmin/docs/Trenz_Electronic/TE0600/TE0600/REV03/Documents/TRM-TE0600-03.pdf
Baseboard TE0603 - http://www.trenz-electronic.de/fileadmin/docs/Trenz_Electronic/TE0600/TE0603/REV03/Documents/SCH-TE0603-03.PDF

Also I offer you to test link with standard 4 lane RJ45 jack where you use only 2 lanes (1,2,3,6) and cut out other lanes.
« Last Edit: January 11, 2018, 04:50:52 PM by Vadim Yunitsky »

joseer

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Re: TE0720 Ethernet interface questions for custom carrier board
« Reply #4 on: January 11, 2018, 05:42:58 PM »
Hi Vadim,

Thanks for the info I'll have a look to the other PHY's options.

Yes, the system will work on 10/100Base, so in theory the 2 additional gigabit Ethernet lanes won't be used  so I'm planning to connect a 10/100Base RJ45 jack (which we already have) to TE0720 as I described in the first post,
do you think should it work with the TE0720's PHY ?

Vadim Yunitsky

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Re: TE0720 Ethernet interface questions for custom carrier board
« Reply #5 on: January 11, 2018, 05:46:58 PM »
In my point of view it should work.