Patent ID: 7577018

Claim:
A readout circuit of a magnetic memory comprising: an array of magnetoresistive elements each having a magnetosensitive layer capable of spin-injection magnetization switching, the readout circuit comprising: data writing means for writing first data in the magnetoresistive element; and determining means for determining whether an output waveform from the magnetoresistive element upon writing of the first data by the data writing means is a first waveform outputted when the first data has previously been written in the magnetoresistive element, or a second waveform outputted when second data different from the first data has previously been written in the magnetoresistive element; wherein the determining means comprises: a comparator having two input terminals connected to the magnetoresistive element and to a reference potential, respectively, and wherein, when the comparator outputs a predetermined value indicating that the output waveform from the magnetoresistive element is the second waveform at the time of data writing by the data writing means, the data writing means induces spin-injection magnetization switching in the magnetoresistive layer to write the second data in the magnetoresistive element.