Reluctance random access memory（MRAM）It is a new type of memory, which has the advantages of fast reading speed, high integration and non-volatile. At present, many researches focus on the application of MRAM memory in computer storage system. Because of its many advantages, MRAM has the potential to replace SRAM and DRAM. MRAM memory constructed with MTJ memory cells can be used as cache.
Cache can be set up in almost the same way as SRAM. MRAM and SRAM have similar circuit structure (see Figure 1).
They all select the target operation unit by word line and transmit data by bit line. SRAM has two different bit lines connected to each cell, while MRAM has only one bit line, so the combination of bit line and source line can be regarded as a substitute. Because based onSRAM chipThe readout amplifier can’t be directly used in MRAM memory, so MRAM needs a reference signal, which is usually provided by a pseudo MRAM cell, and its area can be ignored.
Therefore, a large MRAM array is divided into several small arrays. The small array can be connected by h-tree, and the number and size of rows and columns can be optimized by cacti.