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.@.@.v.@.@.
Contributor
Contributor
803 Views
Registered: ‎09-25-2017

Aurora IP Core - Disable Clock Compensation Sequence

I don't care about hot-swapping and I have boards that have a shared clock that is both phase and frequency locked.

How do I disable the clock compensation logic for my case?

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guozhenp
Xilinx Employee
Xilinx Employee
758 Views
Registered: ‎05-01-2013

Why do you want to disable it? Can you just leave it?

Do you need more bandwidth or less resource utilization?

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.@.@.v.@.@.
Contributor
Contributor
743 Views
Registered: ‎09-25-2017

I have the tx/rx simplex example design for Aurora running on a KCU105 in a loopback.

The link goes down for ~600 cycles every so often - we can't go down that long, it is A) too much latency and B) would massively increase the amount of buffering we need to do.

I thought the link doing that was due to clock compensation, so I'd like to disable it or minimize it as much as possible.

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guozhenp
Xilinx Employee
Xilinx Employee
729 Views
Registered: ‎05-01-2013

Do you mean "link down" to Aurora lane_up/channel_up or your data continuous transmission?

CC should not affect the Aurora link.

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.@.@.v.@.@.
Contributor
Contributor
720 Views
Registered: ‎09-25-2017

It looks to me like tready is going down while channel bonding and/or clock compensation occurs - if this goes down, I'm unable to hand data to the core, so I have to buffer it externally.

The ~600 cycles I'm seeing are from channel bonding, and during that time it looks like tready is low, so I'd have to buffer a tremendous amount of data.

The cores are simplex - we do not have a back-channel, so the simplex TX core periodically asserts channel bonding. The best I think I can do (without going full duplex) is to feed back the "rx lane up" to the tx simplex core (1 line) so as to prevent recurring channel bonding (unless there's an error, of course).

So basically I'd need to control channel bonding in the case of a simplex design, in order for the core to continually accept data, unless there's something else I don't understand.

 

 

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