Pattern synchronizing circuit
First Claim
1. A pattern synchronizing circuit comprising:
- pre-clock eliminating means for eliminating one clock pulse from a high-speed clock input thereto upon each application thereto of a pre-clock pulse eliminating signal;
clock dividing means for frequency dividing the high-speed clock output from said pre-clock eliminating means to 1/N;
demultiplexing means for sequentially demultiplexing consecutive bits of high-speed input data into N parallel low-speed sequences on N output lines in synchronization with said high-speed clock and said N sequences of low-speed data are output in synchronization with said frequency divided clock, N being an integer equal to or greater than 2;
post-clock pulse eliminating means, supplied with said frequency divided clock, for eliminating one pulse from said frequency divided clock upon each application thereto of a post-clock pulse eliminating signal and outputting an output clock;
reference pattern generating means for generating N parallel sequences of reference patterns, sequentially displaced apart in phase, in synchronization with the output clock of said post-clock pulse eliminating means;
N comparators, whereby an Nth sequence of low-speed data, composed of data of every Nth bit of N-bit data being sequentially demultiplexed by said demultiplexing means into N parallel sequences and output upon each occurrence of said frequency divided clock is compared with said N parallel sequences of reference patterns, each of said N comparators outputting an agreement or disagreement signal;
asynchronism detecting means for generating said post-clock pulse eliminating signal upon detecting that each of said N comparators has output said disagreement signal; and
synchronization setting means for detecting one of said N parallel sequences of reference patterns with which an Nth sequence of low-speed data is synchronized and for generating said pre-clock pulse eliminating signals of a number corresponding to a line position of said sequence of reference patterns synchronized with said Nth sequence of low-speed data, whereby line positions of said N parallel sequences of low-speed data are sequentially shifted by said corresponding number in said demultiplexing means so that said Nth sequence of low-speed data assumes the same line position as that of said synchronized reference pattern.
1 Assignment
0 Petitions
Accused Products
Abstract
An Nth one of N parallel sequences of low-speed data demultiplexed by a demultiplexer from high-speed input data in synchronization with a high-speed clock is compared by N comparators with N parallel sequences of reference patterns. The N parallel sequences of reference patterns are each generated in synchronization with a frequency divided clock obtained by frequency dividing the high-speed clock into 1/N. When any of the comparators provides a disagreement output at least once, one clock pulse is eliminated by a post-clock eliminating circuit from the divided clock so that the N sequences of reference patterns are each delayed by one bit. When a counter detects that any one of the comparators does not provide the disagreement signal for n consecutive bits, the sequence of reference patterns corresponding to this comparator and the Nth sequence of low-speed data are in synchronization with each other. Clock pulses of the number corresponding to the line position of the synchronized sequence of reference patterns are eliminated by a pre-clock eliminating circuit from the high-speed clock which is applied to the demultiplexer. By this, line positions of the N parallel sequences of low-speed data are sequentially shifted so that the Nth sequence of low-speed data assumes the same line position as that of the synchronized reference pattern, and as a result, the N parallel sequences of low-speed data are synchronized with the N parallel sequences of reference patterns, respectively.
-
Citations
11 Claims
-
1. A pattern synchronizing circuit comprising:
-
pre-clock eliminating means for eliminating one clock pulse from a high-speed clock input thereto upon each application thereto of a pre-clock pulse eliminating signal; clock dividing means for frequency dividing the high-speed clock output from said pre-clock eliminating means to 1/N; demultiplexing means for sequentially demultiplexing consecutive bits of high-speed input data into N parallel low-speed sequences on N output lines in synchronization with said high-speed clock and said N sequences of low-speed data are output in synchronization with said frequency divided clock, N being an integer equal to or greater than 2; post-clock pulse eliminating means, supplied with said frequency divided clock, for eliminating one pulse from said frequency divided clock upon each application thereto of a post-clock pulse eliminating signal and outputting an output clock; reference pattern generating means for generating N parallel sequences of reference patterns, sequentially displaced apart in phase, in synchronization with the output clock of said post-clock pulse eliminating means; N comparators, whereby an Nth sequence of low-speed data, composed of data of every Nth bit of N-bit data being sequentially demultiplexed by said demultiplexing means into N parallel sequences and output upon each occurrence of said frequency divided clock is compared with said N parallel sequences of reference patterns, each of said N comparators outputting an agreement or disagreement signal; asynchronism detecting means for generating said post-clock pulse eliminating signal upon detecting that each of said N comparators has output said disagreement signal; and synchronization setting means for detecting one of said N parallel sequences of reference patterns with which an Nth sequence of low-speed data is synchronized and for generating said pre-clock pulse eliminating signals of a number corresponding to a line position of said sequence of reference patterns synchronized with said Nth sequence of low-speed data, whereby line positions of said N parallel sequences of low-speed data are sequentially shifted by said corresponding number in said demultiplexing means so that said Nth sequence of low-speed data assumes the same line position as that of said synchronized reference pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification