Abstract: A device for simultaneous data input and output and program execution support in digital processors is disclosed. The device includes a plurality of controllable input and output ports for inputting and outputting data from the device, a data cache memory which is selectively couplable to each of the plurality of input and output ports, and a controller for controlling the plurality of input and output ports and the data cache memory. The connectivity and controlablity provided by the present invention effectuates a transfer of data between any of the plurality of input and output ports or the data cache memory. The device provides multiport high-speed and high-throughput non-multiplexed data input and output while maintaining the speed and throughput characteristics of the digital processor because the input/output data transfer takes place simultaneously with digital processor program execution. The processor need not wait for data transfers from external data sources when this device is used.

Abstract: A device for multi-precision and block arithmetic support in a digital processor including a multiplier for multiplying two signed, unsigned or signed and unsigned binary numbers and having a dynamic range greater than -1 to +1, an arithmetic and logic unit for performing arithmetic and logic operations, a barrel shifter for barrel shifting at least one binary number, shifters for selectively shifting the output of the multiplier and multiplexers for selecting and interconnecting the outputs and inputs of the multiplier, the arithmetic and logic unit, the barrel shifter and the shifters.

Abstract: An autozero loop for eliminating offsets in the analog to digital converter section of a voice frequency coder-decoder (CODEC) utilizing an array of capacitors and a linear resistor string. The autozero loop functions with a relatively small time constant to null offsets quickly during the power-up phase of CODEC operation and with a higher time constant after the power-up phase. A dual bandwidth sub-circuit in the loop is connected to a voltage generator and controlled by signals from a logic circuit to operate at different bandwidths and thus provide different offset cancelling feedback signals during the power-up and normal operating phases.