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Understanding Circuit Emulation PIC Clocking Features


All Circuit Emulation PICs support the following clocking features:

  • External clocking—Also known as loop timing. Clock is distributed via TDM interfaces.

  • Internal clocking with external synchronization—Also known as external timing or external synchronization.

  • Internal clocking with PIC-level line synchronization—The PIC’s internal clock is synchronized with a clock recovered from a TDM interface local to the PIC.

This feature set is useful for aggregation in mobile backhaul applications.


The primary reference source (PRS) of the clock recovered from one interface may not be the same as that of another TDM interface. There is a limitation on the number of timing domains that can be supported in practice.

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