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ADIN1300 100Base-TX RGMII delay setting

Hi

I am considering designing with ADIN1300.
So I have a question about the Subsystem RGMII Configuration Register.

I would like to know the values of the clock delay and internal clock delay of RGMII at 100Base-TX.

Register: For GE_RGMII_RX_SEL and GE_RGMII_GTX_SEL, you can specify the delay by (10 to 7) x tu + 400ps.
Registers: GE_RGMII_RX_ID_EN and GE_RGMII_TX_ID_EN allow you to set the internal delay of the 2ns transmit / receive clock.

Will 400ps and 2ns change if I enable RGMII delay (GE_RGMII_100_LOW_LTNCY_EN) at 100Base-TX?
Or is 100Base-TX the same, with a delay of (10-7) x tu + 400ps or 2ns?

Best regards

Yuya

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  • Hi Yuya,

     

    The GeRgmii100LowLtncyEn bit refers to the latency from the MAC to MDI. When this bit is enabled (it is enabled by default) the TX_ER is not used. In switch application TX_ER is not needed since the MAC will never generate errored data. TX_ER is used with repeaters that need to ensure propagation of errors. If TX_ER needs to be used in the TX side (for a repeater/media converted application), the GeRgmii100LowLtncyEn register should be set to "0". This enables TX_ER in RGMII mode but increases the TX latency (~ 20ns increase can be expected). This bit is separate from the RXC/TXC delay settings so it wouldn’t have any impact on these delay settings.

     

    Best Regards,

    Mark

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  • Hi Yuya,

     

    The GeRgmii100LowLtncyEn bit refers to the latency from the MAC to MDI. When this bit is enabled (it is enabled by default) the TX_ER is not used. In switch application TX_ER is not needed since the MAC will never generate errored data. TX_ER is used with repeaters that need to ensure propagation of errors. If TX_ER needs to be used in the TX side (for a repeater/media converted application), the GeRgmii100LowLtncyEn register should be set to "0". This enables TX_ER in RGMII mode but increases the TX latency (~ 20ns increase can be expected). This bit is separate from the RXC/TXC delay settings so it wouldn’t have any impact on these delay settings.

     

    Best Regards,

    Mark

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