Forum Discussion
New ContributorArria10 Transceiver Oversampling
Regular ContributorHi,
The example design document says the following:
The channel runs @ 150 Mbps after reprogramming the clock to 150 Mhz. This 150 Mbps is achieved using 11x oversampling (both on the transmit and receive side), the transceiver itself is configured at 1650 Mbps.
Oversampling has to be at both Tx and Rx side. Tx side you will be sending at the rate much higher than required and at Rx also you will have multiple samples of the same data, hence, oversampling.
For your case XCVR will run at 1250 Mbps only but at the Rx side you need to discard extra samples received.
Hope that clarifies.
Regards
japetersThanks for your answer. I would like to post my solution here that I found in the meantime.
I managed to set up the MGT such that the data (8b10b encoded) is sent at a rate of 125 Mbps. The 10-bit encoded words are handed over to a module that repeats each single bit 10 times, giving me 100-bit wide words. For example, the three-bit word "101" becomes "111111111100000000001111111111". These 100-bit words are sliced into 5 20-bit wide words, which are handed over to the MGT. The IP core of the MGT has to be set up so that it can handle the 20-bit words. The set rate is still at 1250 Mbps, and the clock from the fPLL is set to 625 MHz. With these settings, it works. However, I do not know whether that is the best way to implement 10x Oversampling.
