User guide

Selecting Channel Bonding Schemes
In Arria 10 devices, select PMA and PCS bonding for bonded protocols that are explicitly supported by
the hard PCS blocks. For example, PCI-Express, SFI-S, and 40GBASE-KR.
Select PMA-only bonding when a bonded protocol is not explicitly supported by the hard PCS blocks. For
example, for Interlaken protocol, PMA-only bonding is used and a soft PCS bonding IP is implemented in
the FPGA fabric.
Skew Calculations
To calculate the maximum skew between the channels, the following parameters are used:
• PMA to PCS datapath interface width (S)
• Maximum difference in number of parallel clock cycles between deassertion of each channel's FIFO
reset (N).
To calculate the channel skew, the following five scenarios are considered:
• Non-bonded
In this case, both the PMA and PCS are non-bonded. Skew ranges from 0 UI to [(S-1) + N*S] UI.
• PMA bonding using x6 / xN clock network
In this case, the PCS is non-bonded. Skew ranges from [0 to (N*S)] UI + x6/xN clock skew.
• PMA bonding using the PLL feedback compensation clock network
In this case, the PCS is non-bonded. Skew ranges from [0 to (N*S)] UI + (reference clock skew) + (x6
clock skew).
• PMA and PCS bonding using the x6 / xN clock network
Skew = x6 / xN clock skew.
• PMA and PCS bonding using PLL feedback compensation clock network
Skew = (reference clock skew) + (x6 clock skew).
PLL Feedback and Cascading Clock Network
The PLL feedback and cascading clock network spans the entire side of the device, and is used for PLL
feedback compensation bonding and PLL cascading.
UG-01143
2015.05.11
Selecting Channel Bonding Schemes
3-47
PLLs and Clock Networks
Altera Corporation
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