Parallel transfer pre-emptor

摘要

A borrow look ahead subtractor suitable for use in a FIFO memory is modified to generate the difference between two values more quickly. A borrow look ahead element generates the borrow signals which are supplied to the subtractors in a parallel fashion. This parallel propagation reduces gate delays between the subtractors, resulting in faster operation. Adding additional levels to the borrow look ahead element further increases the speed of the borrow look ahead subtractor. IMAGE