DP83TD510E-EVM: DP83822H should not establish connection with laptop

Hi Shrikant,

Sorry, I am not following your questions completely. Hopefully the following comments answer your concern.

• DP83822 could link up with the PC even when the DP83TD510 is not link up with other link partner.

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Regards,

Hillman Lin

Yes, what you are saying is right, but I want exact reverse operation. When DP83TD510 link up then only DP83822 should link up with PC.

Hi Shrikant,

DP83822 link up with PC is independence with DP83TD510E. 

DP83822 can link up when DP83TD510 is link up.

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Regards,

Hillman Lin

DP83822 can link up when DP83TD510 is link up. Exactly I want this operation, but for this what need to do? 

Hi Shrikant,

Sorry I am still not following your concern. Are you not able to link up in DP83822?

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Regards,

Hillman Lin

Hi,

No issue with link up DP83822.

I want DP83822 in sleep mode at initial when DP83TD510 link up then only DP83822 should linkup.

Regards,

Shrikant

In this case circuit 1 is disconnected from circuit 2.

Now DP83TD510 has no link up but DP83822 has link up because it is connected with PC.

In this situation DP83822 also should not link up even it is connected with PC.

Hi Shrikant,

May I ask why you need DP83TD510 link up before DP83822? I don't think link up will be the concern if you configure DP83822 into 10Mbps.

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Regards,

Hillman Lin

Hi,

DP83822 should link down even it is connected with PC, when DP83TD510 disconnect from other device. This is our application need. Please suggest the solution.

Thanks, 

Shrikant

Hi Shrikant,

Again, DP83822 link up is independence for DP83TD510. DP83822 won't link down if DP83TD510 is link down. 

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Sincerely,

Hillman Lin

Is it possible to generate interrupt (pin no 21) on DP83TD510  while link up and link down ? and if possible then which configuration is needed ?

Hi Shrikant, 

Yes, it is possible to enable an interrupt on pin 21 on any link status change. This can be done by using the following registers. 

0x11[0] = 1 should change the function of pin 21 from PWD to INT

0x12[5] = 1 should enable the interrupt on link status change

Best,

Vivaan

Thank you for the solution.

I have one more question, can we do enable / disable RX_CLK (pin no 19) of DP83TD510 with link up / link down. If we can then how to configure it ?

And how to save changed configuration permanently ?

Hi Shrikant,

If you are configure in MII interface, the RX_CLK will always generate 2.5MHz by default when both the PHY is link up or link down.

If you are configure in RMII slave interface, the RX_CLK will always generate 50MHz by default when both the PHY is link up or link down.

You can configure the PHY into isolate mode to disable RX_CLK through register 0x0000 but you might need to get interrupt indication to set the PHY into isolate mode.

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Regards,

Hillman Lin