In-memory partial checksum calculation with flexible media coverage

A memory device in a memory system, comprising:

• a plurality of memory cells;
• a control circuit in the memory device and configured to read a codeword sequence from the plurality of memory cells, and determine a sub-matrix including multiple non-zero circulants selected from particular matrix rows of a parity check matrix used in a controller of the memory system, the multiple non-zero circulants including multiple non-zero row circulants for each matrix row, wherein each non-zero circulant selected from the parity check matrix comprises a square matrix comprising an identity matrix having diagonal values of ‘1’ and all remaining values of ‘0’;
• and
• a partial checksum calculator configured to perform a partial checksum calculation on a syndrome sequence based on the codeword sequence and the sub-matrix.