I/O cell for programmable logic device providing latched, unlatched, and fast inputs

摘要

An input/output cell for interconnecting an I/O pad with internal circuitry in a programmable logic device provides clocked and unclocked inputs through an internal bus to selected logic array blocks. The input/output cell further includes a fast input line in which the I/O pad is directly connected with a selected logic array block without travelling through the latch circuitry of the I/O cell and the internal bus of the programmable logic device.