Double buffer type elastic store comprising a pair of data memory blocks

Abstract

In an elastic store supplied with a sequence of reception data, a sequence of reception clock pulses, a sequence of reception frame pulses, a sequence of system clock pulses, and a sequence of system frame pulses comprising successive system frames each of which has a system frame phase, a first signal generating circuit alternately controls write-in operation of first and second data memory blocks in response to the reception clock pulses and the reception frame pulses. The first and the second data memory blocks thereby memorize the reception data as first and second memorized data, respectively. A second signal generating circuit alternately controls read-out operation of the first and the second data memory blocks in response to the system clock pulses and the system frame pulses. The first and the second data memory blocks thereby deliver the first and the second memorized data as first and second read-out data, respectively. A selector selects one of the first and the second read-out data as selected data and delivers the selected data as output data synchronized with the system frame phase within a predetermined phase difference.