Patent ID: 6678287
Filing Date: 2004-01-13
Classification: H03K,H04J

Abstract:
A method for selectively multiplexing a plurality of signal lines through an I/O pin on a semiconductor chip without using separate pins for transmitting multiplexer selection information, comprising:initializing a transmitting circuit and a receiving circuit to selectively multiplex the plurality of signal lines from the transmitting circuit through the I/O pin and into the receiving circuit; wherein the initializing includes selecting at least one of the plurality of signal lines to be multiplexed and transmitting the selection information through the I/O pin, which is also used for subsequent data transmission; synchronizing the transmitting circuit and the receiving circuit by asserting a reset signal coupled to both the transmitting circuit and the receiving circuit; and multiplexing the selected signal lines from the transmitting circuit through the I/O pin and into the receiving circuit, so that selected signal lines are directed into corresponding memory elements in the receiving circuit; wherein the transmitting circuit and the receiving circuit are driven by a common clock signal coupled to both the transmitting circuit and the receiving circuit.