OUTPUT BUFFER CIRCUIT OF SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE: An output buffer circuit of semiconductor integrated circuit is provided of which drive capability can be changed according to programs of register by making one output buffer circuit constituted with plural number of output buffers and switch. CONSTITUTION: An output buffer circuit of semiconductor integrated circuit comprises: at least one output pad; an output buffer circuit which is connected to the output pad and operates the pad according to controls of pull up and pull down signals. The output buffer circuit includes: a first input terminal which receives the pull up signals; a second input terminal which receives the pull down signals, plural number of output buffers which have output terminals that comprise PMOS transistor and NMOS transistor; and plural number of switches connected between the output terminals. And additionally a semiconductor integrated circuit generates signals to make on or off the switches and consists of resisters.