Ripple-carry generating circuit with carry regeneration

A carry circuit comprising a plurality of stages, each stage including an input terminal adapted to receive an input carry signal, an output terminal adapted to provide an output carry signal;

• first and second terminals adapted to receive a first and a second signal respectively;
• a third terminal adapted to receive a potential at a first predetermined level;
• a clock terminal adapted to receive a clock signal;
• load means coupled to the output terminal and responsive to the clock signal for controllably setting the output terminal to a second predetermined level;
• transmission gate means having a conduction path coupled in series between the input and output terminals and a control electrode, the transmission gate means being responsive to a control signal applied to the control electrode for providing a relatively low resistance across the conduction path;
• first logic means coupled to the output terminal and responsive to the first and second signals for providing a carry signal to the output terminal;
• second logic means coupled to the control electrode of the transmission gate means and responsive to only the first signal or only the second signal for providing the control signal;
• characterized in that there are included in at least one stage regeneration means comprising third logic means responsive to the input carry signal in the absence of the clock signal for providing an actuation signal and switching means coupled to the input terminal and responsive to the actuation signal for controllably coupling the input terminal to the third terminal.