US Patent 11143702 Test access port circuit capable of increasing transmission throughput

A test access port circuit includes a data input terminal, a reset terminal, a mode selection terminal, at least one test data register set, an auxiliary data register set, an instruction register set, and a controller. The controller is coupled to the mode selection terminal and the instruction register set, and controls the at least one test data register set, the auxiliary data register set, and the instruction register set according to at least mode selection signal received by the mode selection terminal. In a reset terminal input mode, when the controller controls a test data register set of the at least one test data register set to store a first input data bit received by the data input terminal, the auxiliary data register set stores a second input data bit received by the reset terminal.