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Connecting two Marvell PHY devices to one Cyclone III FPGA

Altera_Forum
Honored Contributor II
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Hi, 

 

- We need to send data from one Cyclone III development board to two receivers. One of these receivers is a displaying panel while the other one is sent to another cyclone III development board (that is connected to a displaying panel too). 

 

- This is implemented as shown in the attached image, by branching the required signals like mdio, mdc,data,.. . 

 

When assigning the mdio to two pins one of them is D2 in bank 1 and the other one is the already assigned pin in cyclone III development board (AB2) "PHY not found in PHY profile" error occurred. If changing the pin location to IOBANK_1 , the connection is successfully established & there is no error detected. 

 

Kindly note that this error occurred without connecting the second board? 

 

Can any one help us. 

 

Thanks & Regards
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Altera_Forum
Honored Contributor II
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Why do you use two extra pins? Both PHYs can be connected to the same MDC/MDIO lines. 

Anyway I think your problem is with ORing the mdio_in signals. A non driven mdio line will pull to a high level, then the OR gate will always result in receiving all ones. 

Replace OR with AND.
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Altera_Forum
Honored Contributor II
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--- Quote Start ---  

Why do you use two extra pins? Both PHYs can be connected to the same MDC/MDIO lines. 

Anyway I think your problem is with ORing the mdio_in signals. A non driven mdio line will pull to a high level, then the OR gate will always result in receiving all ones. 

Replace OR with AND. 

--- Quote End ---  

 

 

 

Thank you very much for your reply :) 

 

1- We use extra pins to connect to another PHY that is not existing in Cyclone III development board. These pins are connected to the second designed board via the HSMC connector 

 

2- Regarding your suggestion we are going to replace the Or gate with an AND one. 

 

Kind Regards
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