Patent ID: 7031197

Claim:
A method of writing and reading data in an EEPROM using a single supply voltage, the EEPROM including a memory cell array having a plurality of memory cells, each memory cell comprising a storage transistor having a source and a drain, a floating gate and a control gate disposed over the floating gate, said method comprising steps of: the method of writing data including steps of, applying a first voltage higher than both the supply voltage and a ground voltage to at least one of the source and drain of the storage transistor of each of selected memory cells, the first voltage being generated from the single supply voltage; and applying a second voltage lower than both the supply voltage and the ground voltage to the control gate of the storage transistor of each of the selected memory cells, the second voltage being generated from the single supply voltage, whereby electrons are released from the floating gate when both the first and second voltages are applied to the storage transistor by said applying steps for writing data, and the method of reading data including steps of, applying the first voltage to the control gate of the storage transistor of each of selected memory cells; and applying a second voltage to at least one of the source and drain of the storage transistor of each of the selected memory cells; whereby electrons are injected to the floating gate when both the first and second voltages are applied to the storage transistor by said applying steps for reading data.