Signal-Margin-Screening for Multi-Mb MRAM

As MRAM technology is maturing, the need for developing a strategy to identify and replace marginal bits during read/write operation becomes necessary. The methodology and circuit techniques for read/write signal-margin screening implemented in a 0.18mum 16Mb MRAM design, are described. The methodology leads to increased read/write signal margins resulting in fully functional dice by applying a wafer-level screen test including half select disturb pattern