A bi-directional shift-register circuit for outputting data in different turns according to a switching signal. Each shift-register unit includes a first input terminal, a second input terminal, an output terminal and a clock input terminal for receiving the clock signal. The first switching circuit is coupled to the output terminal of the pre-stage shift-register unit, the output terminal of the next-stage shift-register unit and the switching signal, and outputs the signal of the output terminal of the pre-stage shift-register unit to the first input terminal of the present-stage shift-register unit and outputs the signal of the output terminal of the next-stage shift-register unit to the second input terminal of the present-stage shift-register unit when the switching signal is at a first voltage level, and outputs the signal of the output terminal of the next-stage shift-register unit to the first input terminal of the present-stage shift-register unit and outputs the signal of the output terminal of the pre-stage shift-register unit to the second input terminal of the present-stage shift-register unit when the switching signal is at a second voltage level.
A bidirectional shift register is disclosed which comprises a first and second flip-flop, a first multiplexer having an output coupled to an input of the first flip-flop, and a second multiplexer having an output coupled to an input of the second flip-flop wherein an output of the first flip-flop is coupled to an input of the second multiplexer, an output of the second flip-flop is coupled to an input of the first multiplexer.
A switch set used in a bi-directional shift register circuit includes a plurality of switch devices. Each switch device is controlled by corresponding control signals to switch the direction of the input signal. One of the switch devices includes a first switch unit for transmitting a shift register signal from a previous shift register to a shift register according to a first control signal, a second switch unit for transmitting a shift register signal from a next shift register to the shift register according to a second control signal. The first and the second control signals have the same frequency as the clock signal of the shift register circuit.
A disable circuit for using in a dynamic shift register unit comprising: a first input, a second input, an output, a first reference line for receiving a first supply voltage, a second reference line for receiving a second supply voltage, and six transistors. The disable circuit is capable of being coupled with a dynamic shift register unit having an input for receiving an input pulse and an output for outputting a shifted pulse. The disable circuit generates an output signal during an input pulse period or an output pulse period for the dynamic shift register unit, wherein the input pulse period and the output pulse period are responsive to a first input pulsed signal from the first input and a second input pulsed signal from the second input, respectively.
