Skewed input (wavefront)
Beginner
Feeding the numbers into the grid in a staircase, one tick later for each row, so the right numbers meet in the right cell.
Novice
Delaying the data entering row of a systolic array by clock cycles. Because values move one PE per cycle, the delay makes matching operands arrive at each PE together, and the active PEs form a diagonal wave.
Expert
Implemented with delay registers or staggered buffer reads at the array edge; the outputs leave equally skewed and are de-skewed on the way out. The skew is one source of the fill-and-drain cycles in the runtime model.