V-Series Transceiver PHY IP Core User Guide

ID 683171
Date 7/26/2022
Document Table of Contents

13.7. xN Non-Bonded Clocking

Non-bonded clocking routes only the high-speed serial clock from the TX PLL to the transmitter channels. The local clock divider of each channel generates the low-speed parallel clock. Non-bonded channels support dynamic reconfiguration of the transceiver.
xN non-bonded clocking has the following advantages:
  • Supports data rate negotiation between link partners on a per-channel basis.
  • Supports data rates are not simple integer multiples of a single base data rate.
  • Supports PLL and channel reconfiguration.

The Native PHY preset for CPRI specifies non-bonded clocks. In multi-channel configurations, CPRI can use both ATX PLLs in a transceiver bank to generate two base data rates. When necessary, CPRI uses dynamic reconfiguration to change the local clock dividers to generate the negotiated clock rate.

The channel span for xN non-bonded clocks is almost identical to the span for bonded clocks as illustrated in Figure 72. However, the center channel that provides central clock divider cannot be used as a data channel because this channel cannot generate the parallel clock. The maximum channel span is 26 channels. There is a single-channel break in the contiguous channel sequence.