Patent ID: 6104637
Filing Date: 2000-08-15
Classification: G11C

Abstract:
An apparatus for programming a threshold voltage of a non-volatile memory cell comprising:a reference voltage generator means applying a predetermined voltage to a word line of a reference memory cell having the same electric characteristics as the memory cell desired to be programmed and generating a reference voltage by thusly generated current;a comparator means comparing the reference voltage with a bit line voltage according to the cell current flowing at the memory cell to be programmed;a word line voltage generator means being controlled by a level count value, selecting word line voltages corresponding to the plurality of threshold voltages of the memory cell to be programmed and outputting it;a word line driving means applying the word line voltages selected by the word line voltage generator means to the word line selected by the word line enable signal;a level data selector means encoding a state data and selectively outputting data corresponding to each level by the level select signal;a latch means being controlled by the output signal from the comparator, latching the data outputted from the level data selector means;a bit line voltage controller means selectively discontinuing programming according to the level of the data latched by the latch means; anda bit line selector means selecting a specific bit line by a bit line enable signal.