Providing write-protection to a memory device

摘要

A system for providing write-protection functionality to a memory device includes: a memory device including configurable registers controlling write and erase operations in the memory device; a system interface; a filter logic device in electrical communication with the memory device and further in communication with the system interface; and a power on reset circuit in communication with the system interface and the filter logic device. The power on reset circuit asserts a reset signal to the system interface on startup of the system. While the reset signal is asserted to the system interface, the filter logic device modifies the configurable registers to prevent all further write and erase operations to the memory device. Then the power on reset circuit de-asserts the reset signal to the system interface enabling communication between the system interface and the memory device. The filter logic device can provide a write-protect signal to the memory device and the memory device prevents write and erase commands when the memory device receives the write-protect signal and the configurable registers are appropriately configured. The filter logic device can be used to protect a memory device which lacks security features, particularly in secure systems such as gaming machines.