Unlock instant, AI-driven research and patent intelligence for your innovation.

Single crystal vibrator digital phase-locked loop device realizing E1/T1 debouncing

A digital phase-locked loop and de-jitter technology, which can be used in synchronization devices, digital transmission systems, automatic power control, etc., and can solve problems such as increasing capacity and increasing costs.

Inactive Publication Date: 2007-08-01
SANECHIPS TECH CO LTD
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The two patents use different crystal oscillators and different control circuits for E1 / T1, so that chips with a large number of channels will increase the capacity, and at the same time, because there are two crystal oscillators, the cost will be increased.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Single crystal vibrator digital phase-locked loop device realizing E1/T1 debouncing
  • Single crystal vibrator digital phase-locked loop device realizing E1/T1 debouncing
  • Single crystal vibrator digital phase-locked loop device realizing E1/T1 debouncing

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0020] E1T1 is a slow data stream. In order to ensure the uniformity of the output clock, a high-speed clock must be used for frequency division. The present invention uses a 58.32M crystal oscillator. However, there will always be a deviation between the input rate and the output rate. In order to ensure the correctness of the data flow, FIFO must be used to absorb the gap between the two sides. At the same time, the deviation between the input and output data streams can be known through the difference between the read and write pointers. And pass it to the frequency division circuit to adjust the ratio of frequency division. By giving the difference between the reference value of E1 and T1 under the 58.32M crystal oscillator and the input data of the 11BIT register, and adding the difference every E1 / T1 cycle in a multi-frame time, the output clock is adjusted according to the carry value Frequency of. Each circuit is described in detail below.

[0021] As shown in Figure...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The single crystal vibrator digital phase-locked loop device realizing E1T1 debouncing includes FIFO, read / write pointer comparator circuit, register-1, subtractor, adder, register-2, E1 / T1 frequency divider circuit, E1 / T1 memory for saving E1 / T1 value, and E1 / T1 selector for selecting E1 or T1 reference value fed to the subtractor. The present invention needs only one crystal vibrator and has the same control circuit for debouncing of both E1 and T1, so that it has reduced chip capacity and low cost.

Description

technical field [0001] The present invention relates to an optical synchronous digital transmission system (abbreviated as SDH / SONET), and specifically relates to a single-crystal oscillator digital phase-locked loop device for 2M / 1.5M PDH interface to realize E1T1 dejittering. Background technique [0002] When VC4 receives it, it is decomposed into 63 TU12 and 84 TU11 signals. To get a pure 2M / 1.5M signal, the overhead and stuffing bytes must be removed, and there may be pointer adjustments in the transmission TU12 / TU11 , so the demapped 2M / 1.5M signal has a gap, if it is directly output to the PDH end, it will cause a lot of jitter. The G.783 protocol has a jitter index limit for the 2M / 1.5M PDH interface. The de-jittering method adopted in the mapping chip is a combination of de-leakage circuit and digital phase-locked loop (DPLL). When the transmitted signal contains two data streams, it is necessary to debounce the two data streams. Through searching, it is found tha...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H03L7/06H04L7/00H04L7/033
CPCH04J3/076
Inventor 郭金玉舒保健田津宁丽霞邓春松
Owner SANECHIPS TECH CO LTD