Are duplicated with all the electronic interchangers the highway data receiver and the manner

摘要

An apparatus and a method for receiving dual highway data in an electronic switching system. First and second highway data are latched in response to an input latch clock signal and any one thereof waits for the output at a rising edge of the input latch clock signal. A parity bit of the first or second highway data is checked and the checked result is outputted for a first half period of a reference clock signal. The reference clock signal has half a period of the input latch clock signal. If a selected one of the first and second highway data has a parity error in accordance with the checked result, it is replaced by the other highway data for a latter half period of the reference clock signal while it waits for the output at the rising edge of the input latch clock signal. The replaced highway data is outputted at the rising edge of the input latch clock signal. If the first and second highway data are both valid and any one thereof has a parity error, a toggling operation is performed to alternately select the first and second highway data. Therefore, when parity errors are successively or randomly generated in one highway data due to a failure in a data reception integrated circuit or cable contact badness, the other highway data with no parity error can be accurately selected.