KR200178748Y1 - Apparatus for duplicated clock generation/distribution in the atm switching system - Google Patents

Abstract

The present invention relates to an Asynchronous Transfer Mode (ATM) switching system, and in particular, a redundant clock in an ATM switching system capable of generating and distributing a system clock provided in a switch block and various matching blocks in one board. A generation / distribution apparatus.

Conventionally, since the clock generation means and the clock distribution means are connected by separate cables, there is a disadvantage that jitter occurs in the clock input from the clock distribution means or the clock stability is not reliable due to synchronization loss. As the distribution board is used, component cost and manufacturing cost increase.

In the present invention, when generating and distributing the system clock required in the switch block and various matching blocks of the ATM switching system, the clock generation and distribution function is performed in one board, thereby preventing delay or jitter of the system clock. It is possible to prevent the loss of synchronization to provide a stable system clock, and to reduce the number and volume of circuit boards, improving the economics.

Description

Apparatus for duplicated clock generation / distribution in the ATM switching system

The present invention relates to an Asynchronous Transfer Mode (ATM) switching system. In particular, a redundant clock generation / distribution in an ATM switching system capable of generating and distributing a system clock provided in a switch block and various matching blocks in one board. Relates to a device.

In general, a clock generation / distribution apparatus in an ATM switching system includes a clock generation means 10 for generating a system clock and a clock distribution means 20 for distributing the generated clock as shown in FIG. 1. Lose.

The clock generating means 10 receives an externally provided synchronization reference clock, generates a system clock synchronized with an external synchronization reference clock in a DP-PLL (Digital Processing Phase Locked Loop) method, and provides the clock distribution means to the clock distribution means 20. Perform the function.

The clock distribution means 20 distributes the system clock provided from the clock generation means 10 to a switch block and various matching blocks through an intermodule interface. Here, the clock generation means 10 is configured by triplexing the three clock generation boards (11 to 13) in consideration of the stability and reliability of the clock, the system clock generated from each clock generation board (11 to 13) Is duplicated and output to the clock distribution means 20 side.

In addition, the clock distribution means 20 is doubled into two clock distribution boards 21 and 22 in order to maintain reliability, and the system clock provided from each clock generation board 11 to 13 of the clock generation means 10 is provided. Select one of the outputs.

That is, when the system clocks (Clock0 to Clock2) generated by the clock generation boards 11 to 13 of the clock generation means 10 are outputted to the clock distribution means 20, the clock distribution board of the corresponding clock distribution means 20 ( 21 and 22 select one of the system clocks provided from the clock generating means 10 as a system reference clock and distribute the same to the switch block and various matching blocks through the inter-module interface.

As described above, in the conventional redundant clock generation / distribution apparatus, the clock generation means and the clock distribution means are connected by separate cables, so that the clock stability may be reliably clocked due to jitter or loss of synchronization from the clock inputted from the clock distribution means. There is a problem that is not present, and there is a problem that the unit cost and manufacturing cost increases as a plurality of clock generation boards or distribution boards are used.

The object of the present invention is to solve the above-mentioned problems. The purpose of the present invention is to perform a clock generation and distribution function for a system clock required for a switch block and various matching blocks of an ATM switching system, thereby delaying the corresponding system clock. In addition to preventing jitter, it is possible to provide a stable system clock and to reduce the quantity and volume of circuit boards.

1 is a block diagram illustrating a redundant clock generation / distribution apparatus in a conventional ATM switching system.

2 is a block diagram of a redundant clock generation / distribution apparatus in an ATM switching system according to the present invention;

3 is a detailed block diagram of the redundant clock generation and distribution board in FIG.

* Description of the symbols for the main parts of the drawings *

30: clock generation board 40a, 40b: clock generation and distribution board

41: clock generator 42, 43: clock divider

The present invention for achieving the above object, in the redundant clock generation / distribution apparatus of the ATM switching system for distributing the system clock to the switch block and various matching blocks, the system clock synchronized with the external reference clock provided from the outside It includes a redundant clock generation and distribution board that generates and distributes to the switch block and various matching blocks.

On the other hand, the clock generation and distribution board, the clock generator for generating a system clock synchronized with an external reference clock provided from the outside; The apparatus may further include a redundant clock divider that receives a system clock from the clock generator and distributes the system clock to a switch block and various matching blocks through an interface between modules.

Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention in detail as follows.

The redundant clock generation / distribution apparatus in the ATM switching system according to the present invention includes two clock generation and distribution boards 40a and 40b as shown in FIG. 2. Each of the clock generation and distribution boards 40a and 40b generates a system clock based on an external reference clock provided from the outside, and distributes the clock to the switch block and various matching blocks, as shown in FIG. 3. It consists of a generator 41 and two clock dividers 42 and 43.

The clock generator 41 generates a system clock having good stability and accuracy in a DP-PLL synchronization manner to an external reference clock provided from the outside and provides the clock to the clock dividers 42 and 43. The clock distributors 42 and 43 receive a system clock from the clock generator 41 and distribute the system clock to switch blocks and various matching blocks through an interface between modules.

Referring to the redundant clock generation and distribution operation in the ATM switching system according to the present invention configured as described above are as follows.

That is, an external reference clock is provided to each clock generation and distribution board 40a and 40b, and the clock generator 41 of each clock generation and distribution board 40a and 40b is DP-PLL synchronized with the external reference clock. Therefore, a system clock having good stability and accuracy is generated and provided to each of the clock distribution units 42 and 43 so that the system clock is duplicated.

On the other hand, the clock distribution units 42 and 43 of the clock generation and distribution boards 40a and 40b provide the system clock provided from the clock generation unit 41 to the switch block and various matching blocks through the inter-module interface. In this case, the clock distribution units 42 and 43 output the system clocks in pairs through the output ports and provide the corresponding switch blocks and various matching blocks to duplicate and distribute the system clocks.

That is, the clock generation and distribution boards 40a and 40b generate their own system clocks and simultaneously distribute and distribute the system clocks to switch blocks and matching blocks. Can be distributed. In addition, the clock generation and distribution boards 40a and 40b include a clock generation unit and a clock distribution unit, thereby reducing the quantity and volume of the circuit board.

As described above, the present invention performs the clock generation and distribution functions for the system clocks required by the switch block and various matching blocks of the ATM switching system in one board, thereby preventing the delay or jitter of the system clock. This provides a stable system clock, and can reduce the number and volume of circuit boards, improving the economics.

Claims (2)

A clock generation / distribution apparatus of an ATM switching system for distributing system clocks to switch blocks and matching blocks, ATM switching system comprising a redundant clock generation and distribution board configured to generate a system clock synchronized with an external reference clock provided from the outside and distribute the same to the switch block and various matching blocks in one board Clock generation / distribution device in. The method of claim 1, The clock generation and distribution board may include: a clock generator which generates a system clock synchronized with an external reference clock provided from the outside; And a redundant clock divider for receiving a system clock from the clock generator and distributing it to the switch block and various matching blocks through an interface between modules.