LOW-POWER RETENTION FLIP-FLOPS

摘要

A retention flip-flop is provided. The flip-flop includes a clock generation circuit, a master latch circuit, and a salve latch circuit. The clock generation circuit generates first and second clock signals at a first mode. The master latch circuit performs a first latch operation on an input signal from the input terminal according to the first and second clock signals to generate a first latched signal at a first node at the first mode. The salve latch circuit performs a second latch operation on the first latched signal according to the first and second clock signals to generate a second latched signal at a second node at the first mode. At a sleep or power-down mode, the total number of transistors in the clock generation circuit and the salve latch circuit is equal to or less than eight.

主权项

1. A flip-flop having an input terminal and an output terminal, comprising:
a clock generation circuit to generate a first clock signal and a second clock signal inverse to the first clock signal when the flip-flop is at a first mode; a master latch circuit to perform a first latch operation on an input signal from the input terminal according to the first clock signal and the second clock signal to generate a first latched signal at a first node when the flip-flop is at the first mode; and a salve latch circuit, coupled to the first node, to perform a second latch operation on the first latched signal according to the first clock signal and the second clock signal to generate a second latched signal at a second node when the flip-flop is at the first mode, wherein the second latched signal is coupled to the output terminal of the flip-flop, and the salve latch circuit comprises:
a first inverter having an input terminal coupled to the first node and an output terminal coupled to the second node;a first pass gate coupled between the second node and a third node;a second inverter having an input terminal coupled to the third node and an output terminal coupled to the input terminal of the first inverter.