Device and method with memory

A method comprising:

• performing outer product and accumulation operations between column vectors of a first size including non-zero (NZ) values of a first input matrix and row vectors of a second size including NZ values of a second input matrix received from a memory cell array;
• storing an operation result based on each column vector and row vector of a multiply-accumulate (MAC) array in an output buffer, wherein the output buffer has a predetermined tile size corresponding to the first size and the second size;
• and
• loading the operation result from the output buffer to a vector register file and providing the operation result to the MAC array for performing an accumulation operation.

A method comprising:

• generating first submatrices by dividing a first input matrix by a first size in a row direction;
• generating second submatrices by dividing a second input matrix by a second size in a column direction;
• performing, for each element of a column vector of a first submatrix of the first submatrices, a product operation between the element of the column vector and each element of a corresponding row vector of a second submatrix of the second submatrices;
• and
• based on results of the product operations, generating a final operation result by performing, for each of the first submatrices, outer product and accumulation operations between column vectors of the first submatrix and row vectors of each of the second submatrices.