High capacity elastic store having continuously variable delay

An elastic store for receiving data bits at a variable line rate comprising

• a first buffer store (102) having a number of storage cells (201, 202, 203, 204),
• first means (205, 206) for writing in said data bits into said storage cells at said variable line rate, and
• a second buffer store (104) having a number of addressable storage cells,
• means for addressing (110) the storage cells in said second buffer,
• characterized by
• secod means (513, 514, 515, 516, 517, 518, 519) for reading out said data bits from said first buffer store and writing in said bits into addressed cells in said second buffer store at a given rate, the read-out cycle of said first buffer normally occurring subsequent to the write-in cycle of said first buffer,
• third means (513, 514, 519, 120) for reading out said data from said second buffer store at a predetermined rate,
• control means (112) for rendering variable the number of storage cells in said second buffer that are addressed, and
• first buffer monitor means (501, 502, 503, 504, 506) for examining the phase between the read-out and write-in cycles of said first buffer and producing control signals when the phase drifts by a preselected amount, said control signals causing said given rate to increase or decrease depending upon the relative direction of said drift, said control signals further directing said control means to respectively increase or decrease the number of storage cells in said second buffer that are addressed.