Method and apparatus for framing data in a digital transmission line
First Claim
1. A circuit for framing data in a digital transmission line comprising:
- a buffer coupled to an input signal, said input signal including data and flaming information bits, wherein said buffer is operative to output an output signal derived from said input signal in accordance with an external output clock;
a frame aligner coupled to said input signal, wherein said frame aligner is operative to determine which of said data and framing information bits are flaming information bits and to recognize a flaming format created by said framing information bits, said framing format being one of a plurality of predetermined framing format, and wherein said frame aligner is operative to output a frame aligning signal when a framing format is recognized; and
an output counter coupled to said frame aligning signal operative to count said data and framing information bits and output a frame synchronization signal in accordance with said output clock when a framing information bit is counted.
0 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for framing data in digital transmission lines automatically recognizes a framing format. The apparatus preferably includes a frame alignment apparatus that can recognize any one of a number of predetermined framing formats created by framing information on an input signal. The frame alignment apparatus outputs an aligning signal to an output frame counter, which counts the data and framing information on the input signal and outputs a frame synchronization signal according to the framing format. The input signal is also coupled to an output apparatus that outputs the input signal at the clock rate of a terminating apparatus. The frame alignment apparatus preferably includes a plurality of pattern recognizers able to recognize at least one of the framing formats and a storage apparatus for storing counts of successive data and framing information that match a framing pattern. The counts are preferably used to identify the framing information on the input signal and the framing format.
41 Citations
21 Claims
-
1. A circuit for framing data in a digital transmission line comprising:
-
a buffer coupled to an input signal, said input signal including data and flaming information bits, wherein said buffer is operative to output an output signal derived from said input signal in accordance with an external output clock; a frame aligner coupled to said input signal, wherein said frame aligner is operative to determine which of said data and framing information bits are flaming information bits and to recognize a flaming format created by said framing information bits, said framing format being one of a plurality of predetermined framing format, and wherein said frame aligner is operative to output a frame aligning signal when a framing format is recognized; and an output counter coupled to said frame aligning signal operative to count said data and framing information bits and output a frame synchronization signal in accordance with said output clock when a framing information bit is counted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A digital reception apparatus for framing data in a digital transmission line, the apparatus comprising:
-
a buffer coupled to an input signal, said input signal including data bits and framing information bits, wherein said data bits are organized in flames and said framing information bits designate successive flames of said data bits, and wherein said buffer is operative to output data bits derived from said input signal in accordance with an external output clock; a frame aligner coupled to said input signal, said frame aligner being operative to determine one of a plurality of possible framing formats from said data and flaming information bits by determining which of said data and flaming information bits are flaming information bits; and an output counter coupled to said frame aligner for counting said data and framing information bits and for outputting a frame synchronization signal, said frame synchronization signal identifying said flames of said output data bits. - View Dependent Claims (19, 20, 21)
-
Specification