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Altera_Forum
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14 years ago

StratixIV GX and SFP

I want use GXB_RX and GXB_TX link to the SFP. The GXB_RX and GXB_TX are LVDS levels. The SFP is LVPECL or CML levels. How to link them? In the StratixIV GT board of Altera, they just li...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Thanks very much for your reply.

I check the StratixIV handbook, the GXB_RX and GXB_TX are PCML signals.

I want to communication with 2.5GHz SFP(small form-factor pluggable )models using GXB_RX and GXB_TX pins. In SFP, the tx and rx are AC coupled LVPECL signals.

My questions are,

1. how to link GXB_RX and GXB_TX pins with SFP? Just connect them directly or using some voltage level change chips? In the schematic of StratixV developboard, they connect directly.

2. What PCML standard should chose, 1.4 V PCML, 1.5 V PCML or 2.5 V PCML?

3. In configing ALTGX ip, the Vcm is 0.82V or 1.1V?

Thanks.