An output buffer holds N words arranged as N/J mutually exclusive output buffer word groups (OBWG) of J words each. N processing units (PU) are arranged as N/J mutually exclusive PU groups each having an associated OBWG. Each PU has an accumulator, an arithmetic unit, and first and second multiplexed registers each having at least J+1 inputs and an output. A first input receives a memory operand and the other J inputs receive the J words of the associated OBWG. Each accumulator provides its output to a respective output buffer word. Each arithmetic unit performs an operation on the first and second multiplexed register outputs and the accumulator output to generate a result for accumulation into the accumulator. A mask input to the output buffer controls which words, if any, of the N words retain their current value or are updated with their respective accumulator output. The processing unit group operates as a long and short term memory cell for the time recurrent neural network.
Neural network unit using processing unit group as recursive neural network for short and long term memory cells for operation