Tag Archives: fillword

Signal quality and link stability

I really think I should stop with fillword discussions but here is one more. What happens even if you have set the correct fillword, have made sure all hardware is in tip-top shape and still the encoding errors fly around like a swarm of hornets. Then the problem of ISI might be more problematic.

The main issue still is that the receiving side is unable to distinguish between a 0 and 1. The so called eye-pattern is too narrow or too distorted in such a way the receiver is just seeing gibberish.

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Fillwords IDLE vs ARBff (one last time)

I’ve written about fillwords a lot (see here, here, and here) but I didn’t show you much about the different symptoms an incorrect fillword setting may incur.

As you’ve seen fillwords are a very nifty way of maintaining bit and word-sync on a serial transmission link when no actual frames are sent. Furthermore they also are replaceable with other primitive signals (Like R_RDY, VC_RDY etc) to utilize a very simple instruction method between two ports without interfering with actual frames. That means that fillwords are ALWAYS squeezed in between frames.


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