SERIAL INTERFACE CAPABLE OF OPERATING IN TWO DIFFERENT SERIAL DATA TRANSFER MODES

摘要

A serial interface includes a first port capable of transmitting and receiving data in a serial fashion. A first p-channel transistor is coupled to the first port. A first n-channel transistor is coupled to the first port. A first control circuit is coupled to the first p-channel transistor for disabling the first p-channel transistor so that the first port can operate in a first serial data transfer mode wherein the first n-channel transistor operates in an open-drain fashion. A second port is capable of transmitting and receiving a clock signal which is used to control data transfer through the first port. A second p-channel transistor is coupled to the second port. A second n-channel transistor is coupled to the second port. A second control circuit is coupled to the second p-channel transistor for disabling the second p-channel transistor so that the second port can operate in the first serial data transfer mode wherein the second n-channel transistor operates in an open-drain fashion.