Patent ID: 7158400

Claim:
A method of operating a dynamic random access memory (DRAM) using a bit line and a bit line bar, wherein a charge storage device of the DRAM is adapted for storing data, and is coupled to the bit line via a switch device, the method comprising: programming the charge storage device with a data status of a first status or a second status; and accessing the data stored in the charge storage device, accessing the data comprising: providing the bit line and the bit line bar with an initial bias, wherein the bit line has a first-status bias when the bit line is coupled to the charge storage device in the first status and the bit line has a second-status bias when the bit line is coupled to the charge storage device in the second status; providing the bit line bar with a sensing bias approximately when the bit line is coupled to the charge storage device, wherein the sensing bias is different from the initial bias of the bit line and is between the first-status bias and the second-status bias; coupling the bit line with the charge device to obtain a read-out level at the bit line; and identifying the data status of the charge storage device by comparing the read-out level with the sensing bias.