Read only memory devices with independently precharged virtual ground and bit lines and methods for operating the same

摘要

Read only memory (ROM) integrated circuit devices include one or more storage cells. A virtual ground line and a bit line are coupled to the storage cell. A precharge circuit independently controls timing of precharging of the virtual ground line and the bit line. The precharge circuit may be configured to deactivate precharging of the virtual ground line before deactivating precharging of the bit line. Precharging of the virtual ground line may be deactivated substantially concurrently with activation of discharging of the virtual ground line. Methods of operating such ROM integrated circuit devices are also provided.