Inventors:
Nikola S. Subotic - Ann Arbor MI
Michael T. Eismann - Saline MI
International Classification:
G11C 1300
Abstract:
Two dimensional charge coupled device (CCD) memories are coupled to acoustic charge transport devices (ACT) which act as input and/or output multiplexers for the memories. In a preferred embodiment of the invention, the input to a NXM memory is in the form of an optical image projected on the CCD device and the output stage of each column of the memory is provided to one of N FET switches. A 1-D ACT device has multiple taps each connected to the gate of one of the FET switches and as an impulse signal propagates along the ACT channel, the FET switches are successively triggered causing the column outputs to be provided to a summing device to generate a serial output. In an alternative embodiment forming a corner-turn memory, an ACT tapped delay line has a number of equally spaced electrode taps equal to the number of columns of a CCD corner-turn array and each tap is connected to an electrical switch which in turn is connected to an input cell of a bordering row of the array. A serial data stream which may be either analog or digital is provided to the electrical switches which are timely activated by the ACT device and is fed in parallel to the array and then shifted between columns, in parallel, to fill the array. An output ACT multiplexer employing FET switches is provided orthogonally to the input multiplexer and receives the output of each column of the array and generates a serial output stream.