Metering pulse generation circuit of farm-village exchange system

摘要

end. TECHNICAL FIELD OF THE INVENTION;And more particularly, to a metering pulse generating circuit for charging a meter in a subscriber line interface circuit of a farm / village switcher (SDX-RB) in a private exchanger or a public telephone providing a service by sending a metering pulse.;I. Technical Problems to be Solved by the Invention;It is possible to climb the fare when the service is provided from a private exchange or public telephone connected to the farm-and-village exchange system.;All. Summary of the Invention:;A decoder which is enabled by subscriber line car enable (/ CARD EN) data and outputs a subscriber selection enable signal by decoding channel allocation signal BA12 and port selection signal BA3; An address latch for latching the billing start data D3 and the channel address A0 to A2 upon being enabled by the enable signal and outputting a channel selection signal for selecting a corresponding channel among 16 channels per subscriber, A clock generation unit receiving a signal FS and a system clock signal / 2MCLK to generate a metering synchronization signal Msync and a metering pulse signal MSO; And for outputting 16 switching selection signals for interrupting the metering pulses sent to the 16 subscriber ports in synchronization with the metering synchronization signal (Msync) outputted from the clock generating section, Constitute the adjustment element.;la. Important Uses of the Invention;Applies to agricultural and fishery exchanges.