US 6,888,826 B1 · Pointer generator design that provides multiple outputs that can be synchronized to different clocks

Abstract

A SONET multiplexed communications system that facilitates the sharing of processing resources while reducing overall system complexity. The SONET multiplexed communications system includes a single multi-output pointer generator clocked by a system clock and a plurality of clock domain transfer circuits having respective FIFO buffers for transferring SONET signals from the system clock domain to respective outgoing line clock domains. The multi-output pointer generator and the clock domain transfer circuits compensate for timing differences between the system clock and the respective outgoing line clocks by either skipping or overwriting FIFO buffer address locations corresponding to TOH byte positions in outgoing SONET frames. The TOH bytes corresponding to the skipped or overwritten TOH byte positions are subsequently re-generated by respective TOH insertion circuits before the outgoing SONET frames are passed through outgoing SONET lines.

Claims19

Dependent claims

A SONET multiplexed communications system, comprising:

pointer processing circuitry clocked by a first clock, the pointer processing circuitry being configured to process at least one SONET signal comprising data and overhead information;
at least one overhead information insertion circuit clocked by a second clock, the insertion circuit being configured to re-generate the overhead information and insert the re-generated overhead information in the SONET signal;
and
at least one clock domain transfer circuit coupled between the pointer processing circuitry and the insertion circuit, the clock domain transfer circuit including at least one first buffer having a plurality of addressable locations configured to store the data and overhead information of the SONET signal,
wherein the clock domain transfer circuit is configured to compensate for timing differences between the first and second clocks by addressing the plurality of first buffer locations for selectively overwriting or skipping at least one location corresponding to the overhead information of the SONET signal.

2 more elements

Dependencies are inferred from the claim text.

Pointer generator design that provides multiple outputs that can be synchronized to different clocks

Life of this patent

Pointer generator design that provides multiple outputs that can be synchronized to different clocks

Life of this patent

Abstract

Claims19