DP83869HM: DP83869HM

Hi,

125MHZ is the clock requirement of GTX clock for 1000MBPS(RGMII) to Fiber mode conversion. This GTX clock is input in RGMII mode, Can we short RX clock and GTX clock for RGMII to fiber mode media convertor?

Please suggest.

Hi Vysali, 

The GTX clock signal is sourced from the MAC interface being used to ensure that proper sampling of the data is done by the PHY. It cannot be shorted to RX_CLK since that is the PHYs recovered clock, not the MACs transmitted clock. 

Best,

Vivaan

Hi,

Thanks for the clarification.

Do we need to use 125MHz clock externally incase of media convertor. As this chip converts copper to fiber and no need of the MAC interface, please suggest how to connect this GTX clock.

Hi Vysali, 

1000BASE-T to 1000BASE-X conversion mode does not use a MAC interface and therefore does not need a GTX clock. The MAC interface would only come into play for RGMII to 1000BASE-X conversion.

vysali kottapudi said:

1000MBPS(RGMII) to Fiber mode conversion.

Are you trying to convert 1000BASE-T to 1000BASE-X or RGMII to 1000BASE-X ?

Best,

Vivaan

Hii,

Thanks for reply.

We are trying media conversion of RGMII to 1000Base-X. please suggest how to connect GTX clock, RX and TX signals.

Hi Vysali, 

Since you are using a RGMII input, the GTX Clock, and all RX/TX signals should be connected to the MAC being used.

Best,

Vivaan

HIi,

 As strap options are available, we understood no need of external controller for RGMII to fiber media converter(RGMII to 1000Base-X).

Is it required to use an external controller for RGMII to fiber media conversion also or can we use media converter for RGMII to Fiber without any external controller????? 

Hi Vysali, 

I am not sure what you mean by an "external controller". Are you talking about MDIO Access to change memory registers or the MAC?

Best,

Vivaan

Media_Convertor_Schematics.pdf

Hii,

I am sharing my schematics, kindly review and offer your comments. 

Please suggest how to connect TX_D0_1 to RX_D0_1, TX_D3_1 to RX_D3_1, GTX_CLK_1, TX_CTRL_1, RX_CTRL_1,RX_CLK_1 signals.

I mean any external device is required to control the DP83869 to achieve RGMII to fiber mode configuration or only DP83869 capable enough to operate in RGMII to fiber mode configuration by using of STRAP options?

Hi Vysali, 

The 869 can be booted up in RGMII to fiber mode, register access should not be needed for that. However, register access is a useful debug tool that lets us know the state that the PHY is in, and it is recommended to keep it. 

vysali kottapudi said:

Please suggest how to connect TX_D0_1 to RX_D0_1, TX_D3_1 to RX_D3_1, GTX_CLK_1, TX_CTRL_1, RX_CTRL_1,RX_CLK_1 signals.

As mentioned earlier, these signals are routed to the host MAC interface from which you are expecting the data to come from. What MAC interface are you using for this?

Best,

Vivaan 

Media_Convertor_block diagram.pdf

We are not using any MAC, as it is suggested in the DP83869 datasheet without any MCU and with strap options we can use DP83869 as media convertor. 

the blcok diagram is attached for your reference, kindly suggest without using any controller(MCU as per datasheet) how to use this DP83869 as a RGMII to Fiber media convertor.

kindly provide your contact so that we will held a meeting regarding this issue so that we will get clarity. or send us a link we will join.

Hii,

We are trying to convert 1000BASE-T to 1000BASE-X. in this scenario how to connect GTX clock, tx and rx signals.

DS83869 how this IC will manage full duplex mode(copper to fiber and vice-versa)? and Tx and Rx signals need to be shorted or left floating in 1000Base-T to 1000Base-X?

Hi Vysali, 

Yes, the DP83869 will manage full duplex copper to fiber media conversion in the 1000M Media Converter Mode. 

vysali kottapudi said:

Tx and Rx signals need to be shorted or left floating in 1000Base-T to 1000Base-X

Vivaan Jaiswal said:

As mentioned in my above comment, for 1000BASE-T to 1000BASE-X, the RX/TX signals do not need to be connected.

As mentioned here, these signals do not need to be connected and can be left floating

Best,

Vivaan