raja.cedt wrote on Nov 21st, 2013, 11:40am:2.Why always TX eye mask will be different than RX mask (actually i don't know how to describe here, TX mask will rectangular,RX will be like rambus shape)
I have designed a transceiver for USB in the past and the TX is rectangular because it needs to be as perfect as it can be before going into the "channel" (in my case, pins, board, connectors and a long USB cable with reflections and mismatches).
The RX pattern that the chip needs to be able to detect will therefore be non-ideal (i.e. rambus shaped), i.e. a very small eye opening. This is due to the imperfections in the "channel" mentioned above.
Depending on where you measure/define your "channel" / system, the TX/RX eye templates will be different (getting worse going from TX to RX)
Was that what you were asking ?