Abstract: A data writing method for mask read only memory using different doses of ion implantations to perform the data writing of Mask Read Only Memory. A semiconductor substrate having a plurality of gate structures is provided. The different ion implantations are performed depending on the mask from the user, thereby generating the different voltage output values. The different voltage output values are set as (00), (01), (10), and (11) for the bit output. Therefore, the present invention reduces the area of memory required for a specific data record, and lowers the production cost.

Abstract: A sense amplifier for Mask Read Only Memory comprising a multiplexer, a plurality of comparators, a plurality of first selected transistors, and a plurality of second selected transistors. The gates of both first selected transistor and second selected transistor are connected to a word line select. One doping area of the first selected transistor is connected to the multiplexer for generating a plurality of signals, and another doping area is connected to a selected bit line. One doping area of each of the second selected transistor is connected to each of the comparators, and another doping area is connected to an external voltage. A cell voltage status is determined when each of the signals and one of doping areas of the second selected transistors are connected to each of the comparators.

Abstract: A data writing method for mask read only memory using different doses of ion implantations to perform the data writing of Mask Read Only Memory. A semiconductor substrate having a plurality of gate structures is provided. The different ion implantations are performed depending on the mask from the user, thereby generating the different voltage output values. The different voltage output values are set as (00), (01), (10), and (11) for the bit output. Therefore, the present invention reduces the area of memory required for a specific data record, and lowers the production cost.

Abstract: A sense amplifier for Mask Read Only Memory comprising a multiplexer, a plurality of comparators, a plurality of first selected transistors, and a plurality of second selected transistors. The gates of both first selected transistor and second selected transistor are connected to a word line select. One doping area of the first selected transistor is connected to the multiplexer for generating a plurality of signals, and another doping area is connected to a selected bit line. One doping area of each of the second selected transistor is connected to each of the comparators, and another doping area is connected to an external voltage. A cell voltage status is determined when each of the signals and one of doping areas of the second selected transistors are connected to each of the comparators.