Computational memory with zero disable and error detection
A processing element includes an input zero detector to detect whether the input from the neighbor processing element contains a zero. When the input from the neighbor processing element contains the zero, a zero disable circuit controls the input from the neighbor processing element and respective data of the memory to both appear as unchanged to the arithmetic logic unit for the operation. A controller of an array of processing elements adds a row of error-checking values to a matrix of coefficients, each error-checking value of the row of error-checking values being a negative sum of a respective column of the matrix of coefficients. The controller controls a processing element to perform an operation with the matrix of coefficients and an input vector to accumulate a result vector. Owing to the error-checking values, when a sum of elements of the result vector is non-zero, an error is detected.
1. A controller of an array of processing elements, the controller configured to:
add a row of error-checking values to a matrix of coefficients, each error-checking value of the row of error-checking values being a negative sum of a respective column of the matrix of coefficients;
load the matrix of coefficients into the array of processing elements as serialized coefficients;
load an input vector into the array of processing elements; and
control the array of processing elements to perform an operation with the matrix of coefficients and the input vector by:
performing a parallel operation with the serialized coefficients in the array of processing elements and the input vector;
accumulating a result vector; and
rotating the input vector in the array of processing elements and repeating the performing of the parallel operation and the accumulating until the operation is complete;
wherein when the operation is complete, a sum of elements of the result vector is computed and an error in the operation is detected when the sum is non-zero.
2. The controller of claim 1 , wherein the controller is configured to repeat the operation using a different array of processing elements when the error is detected.
3. The controller of claim 1 , wherein the sum of elements of the result vector is computed over a finite field.
4. The controller of claim 3 , wherein the finite field is integers modulo a power of 2.