EXECUTION LOOK-UP TABLE OF ADDRESS AND HIGH-SPEED CARRIER FOR COUNTER

摘要

PURPOSE: To provide a high-speed adder (provided with a subtractor) and a counter constituted of a programmable lookup table in a programmable logic device. CONSTITUTION: A conventional lookup table 10 is divided into smaller lookup tables 10a and 10b in the case that the adder or the counter is requested. The divided lookup table 10a outputs total output signals to an output lead wire O/P and the other table 10b outputs high-speed carry out signals to the next stage of the adder or the counter onto lead wires X and Y.