cycloneVGX transreceiver compatibilityi PCML to CML

[Altera_Forum]

Hello to all.. 

       I would understand if this SFP module (see image) is compatible with the transceiver CycloneVgx. In the fpga board the transreiceiver power is 2.5V. The sfp module is CML compatible. Can you help me?  Best regards, Luca

[Altera_Forum]

Does the SFP module you refer to comply with the inf-8074i specification (ftp://ftp.seagate.com/sff/inf-8074.pdf)? I suspect it does. 

 Refer to Altera's "serial gigabit media independent interface (https://www.altera.com/solutions/technology/transceiver/protocols/pro-sgmii.html)" page. This discusses connecting SFP modules to Altera FPGAs, including Cyclone V GX.  Cheers, Alex

[Altera_Forum]

I must use the sfp module at 3.125 Gbps (it support up 4.25Gbps). 

In my application i not use the gIgabit ethernet standard. I need to encode data with 8b/10b and then send it to sfp module.    --- Quote Start ---  Does the SFP module you refer to comply with the inf-8074i specification (ftp://ftp.seagate.com/sff/inf-8074.pdf)? I suspect it does.  Refer to Altera's "serial gigabit media independent interface (https://www.altera.com/solutions/technology/transceiver/protocols/pro-sgmii.html)" page. This discusses connecting SFP modules to Altera FPGAs, including Cyclone V GX.  Cheers, Alex  --- Quote End ---  

[Altera_Forum]

The SFP module is not tied to any particular protocol. It can carry Gig Ethernet but it doesn't have to. 

 So, you should have no problem sending 8b/10b data, at 3.125Gbps, from a Cyclone V GX device (transceiver speed grade 6).  Cheers, Alex

[Altera_Forum]

Hi Alex! 

I agree with you. But my problem is with the electric level compatibility, CML of the SFP module, and the PCML of the fpga     --- Quote Start ---  The SFP module is not tied to any particular protocol. It can carry Gig Ethernet but it doesn't have to.  So, you should have no problem sending 8b/10b data, at 3.125Gbps, from a Cyclone V GX device (transceiver speed grade 6).  Cheers, Alex  --- Quote End ---  

[Altera_Forum]

PCML is Altera's "Pseudo Current Mode Logic". The FPGA's I/O doesn't have a true CML structure - it can't, the I/O is flexible to accommodate a variety of I/O standards. So, Altera have simply named it PCML to clearly show that it isn't true CML. However, it can be used to connect directly** to an SFP module. 

 **Thanks to AC coupling in the serial links on the SFP module.  Have a look through App Note 518 - "sgmii interface implementation using soft cdr mode of altera fpgas (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/an/an518.pdf)". This discusses interfacing SFP modules to FPGAs.  You may want to refer to the following thread too:  (http://www.alteraforum.com/forum/showthread.php?t=30105)http://www.alteraforum.com/forum/showthread.php?t=30105  Cheers, Alex

[Altera_Forum]

Thank you!!:) 

   --- Quote Start ---  PCML is Altera's "Pseudo Current Mode Logic". The FPGA's I/O doesn't have a true CML structure - it can't, the I/O is flexible to accommodate a variety of I/O standards. So, Altera have simply named it PCML to clearly show that it isn't true CML. However, it can be used to connect directly** to an SFP module.  **Thanks to AC coupling in the serial links on the SFP module.  Have a look through App Note 518 - "sgmii interface implementation using soft cdr mode of altera fpgas (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/an/an518.pdf)". This discusses interfacing SFP modules to FPGAs.  You may want to refer to the following thread too: http://www.alteraforum.com/forum/showthread.php?t=30105  Cheers, Alex  --- Quote End ---  

[Altera_Forum]

Hi a_x_h_75! 

I need use a simple protocol 8b/10b in my application (2.5 Gbps DATA and then 3.125Gbps bit stream). Can i use a custom phy megafunction? is it configurable for this pourpose?

[Altera_Forum]

Yes, you can. 

 I suggest you use the "GIGE-2.50Gbps" template (from the library - double click on it) and work backwards from there, changing any settings you need to. Change the "Parameter validation rules" to "Custom" and ensure the 8b/10b encoder/decoder is selected on the "PCS Options" tab.  Cheers, Alex

[Altera_Forum]

GIGE 2500 is 2500Mbps data and then 3125Mbps on wire? 

is it right?    --- Quote Start ---  Yes, you can.  I suggest you use the "GIGE-2.50Gbps" template (from the library - double click on it) and work backwards from there, changing any settings you need to. Change the "Parameter validation rules" to "Custom" and ensure the 8b/10b encoder/decoder is selected on the "PCS Options" tab.  Cheers, Alex  --- Quote End ---  

[Altera_Forum]

That's right. 

Cheers, Alex