DATA RETENTION DEVICE FOR POWER-DOWN APPLICATIONS AND METHOD

摘要

In described example data retention apparatus and methods, data input is latched by a first latch (112). A second latch coupled to the first latch receives the data input (140) for retention while the first latch is inoperative in a standby power mode. The first latch receives power from a first power line that is switched off during the standby power mode. The second latch (114) receives power from a second power line. A controller (130) receives a clock input and a retention signal and provides a clock output to the first latch and the second latch. A change in the retention signal is indicative of a transition to the standby power mode. The controller continues to hold the clock output at a predefined voltage level and the second latch continues to receive power from the second power line in the standby power mode, thereby retaining the data input.