| 摘要 |
A soft error protection circuit is disclosed for a storage cell, such as a latch having a first input/output node and a second input/output node which are respectively connected to a charging source, the first node being selectively charged at least during a write interval, to represent a stored, first binary logic state for the latch. The circuit includes an insulated gate, field effect capacitor having a diffusion electrode connected to the second node and having a gate electrode, for selectively loading the second node with an additional capacitance. An inverter circuit has an input connected to the second node and an output connected to the gate electrode of the capacitor, for applying a capacitance enhancing bias to the gate electrode in at least a read interval following the write interval, when the first binary logic state has been stored in the latch, to apply the additional capacitance to the second node. The charging source supplies charge to both the first node and the second node at least following a soft error event which has caused the first node to become at least partially discharged during the read interval. In accordance with invention, the additional capacitance applied to the second node prevents the second node from recharging as fast as the first node following the soft error event, by sinking a portion of the charge supplied from the charging source to the second node. In this manner, the first node will resume its previously charged condition, thereby preserving the stored logic state. |
