Configuring Transceiver Pins for Cyclone V GX: 1.5V PCML

You had solved?

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Hello, I am using the Cyclone V GX to interface with a Fiber-optic transceiver that is CML. The datasheet for the Fiber-optic transceiver has the following:

Transmitter

Input differential impedance 100-ohms

Single ended data input swing min(90mV) max(350mV)

Receiver

Single ended data output swing min(275mV) max(425mV)

I intend to use the Altera Transceiver PHY IP core to interface with the fiber-optic transceiver. I have been looking over the Cyclone V Datasheet and I believe that should configure the tx/rx differential pins to 1.5V PCML. Also, on page 22 table 21 it lists the TX Vod settings. I believe that I should choose Vod setting 16 which is Vod value 320mV, is that correct?

Using Table 20 I get the following:

Transceiver (AC Coupled)

Vod (max) = 1200mV

Vod (typ) = --

Vod (min) = --

Vocm = 0.65V

Receiver (AC Coupled)

Vid (max) = 1600mV

Vid (typ) = ----

Vid (min) = --

Vicm = 0.8V

I am have not used the Altera transceivers before so what I have described so far does anyone see any red flags? The fiber-optic transceiver has integrated capacitors so I'm thinking of simply connecting the fpga right up to the transceiver tx/rx pins. If anyone has experience with this please share any comments you may have.

thanks,

joe

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Thieulam,

Hello, that was a long time ago and I never received any help from the Forum or Altera. At that time my co-worker saw no red flags. That board has not been built yet and I've had to change to a larger Cyclone. I will be revisiting this again to make sure things are correct. I will let you know how things turn out. Joe

thank you Joe.

I have the same problem with cycloneVgx starter kit (terasic).

I would like to use an SFP module with CML ac coupled interface.

But I do not understand if the standards 1.5V PCML is compatible ..

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Thieulam,

Hello, that was a long time ago and I never received any help from the Forum or Altera. At that time my co-worker saw no red flags. That board has not been built yet and I've had to change to a larger Cyclone. I will be revisiting this again to make sure things are correct. I will let you know how things turn out. Joe

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Hello, it is my understanding that they are compatible. I did have some questions so I referred to Cyclone V Device Datasheet pages 16-18 regarding 1.5V PCML. Here is what I have found.

Transceiver (AC Coupled)Vod (max) = 1200mVVod (typ) = 660mV (my co-worker found this somewhere)

Vod (min) = 120mV (my co-worker found this somewhere)

Vocm = 0.65VReceiver (AC Coupled)

Vid (max) = 1600mVVid (typ) = 200mV(my co-worker found this somewhere)

Vid (min) = 700mV(my co-worker found this somewhere)

Vicm = 0.8V

I also contacted the vendor of the SFP which was very helpful.

You might consider contacting a Field Applications Engineer from Altera, must open a Service Ticket with Altera, ask you questions and also ask contact an FAE.

I think you will be okay.

Thank you.

I open a ticket with altera.

Regards, Luca

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Hello, it is my understanding that they are compatible. I did have some questions so I referred to Cyclone V Device Datasheet pages 16-18 regarding 1.5V PCML. Here is what I have found.

Transceiver (AC Coupled)Vod (max) = 1200mVVod (typ) = 660mV (my co-worker found this somewhere)

Vod (min) = 120mV (my co-worker found this somewhere)

Vocm = 0.65VReceiver (AC Coupled)

Vid (max) = 1600mVVid (typ) = 200mV(my co-worker found this somewhere)

Vid (min) = 700mV(my co-worker found this somewhere)

Vicm = 0.8V

I also contacted the vendor of the SFP which was very helpful.

You might consider contacting a Field Applications Engineer from Altera, must open a Service Ticket with Altera, ask you questions and also ask contact an FAE.

I think you will be okay.

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Thank you.

I open a ticket with altera.

Regards, Luca

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Hello,

I have the same doubt. Instead of launching another request to Altera, would you be able to share with us the answer Altera gives you?

Thank you.

Best regards,

Carlos

The answer of altera:

The PCML is compatible with any CML sfp ac coupled.

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Hello,

I have the same doubt. Instead of launching another request to Altera, would you be able to share with us the answer Altera gives you?

Thank you.

Best regards,

Carlos

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