MRAM based FPGA
orres explained that the current technology used is Thermally Assisted Switching (TAS)-MRAM with a small current for heating the Magnetic Junction Tunnel, allowing a higher sensitivity to magnetic fields. The magnetic field is induced by a current line above or below the junction depending on the technology.
He noted:"The main advantage to use TAS in comparison to field-induced magnetization switching (FIMS) is that the current needs to induce the magnetic field are divided by two (between 5 to 10mA). It is clear that for power consumption the best solution is STT. Our cell also supports STT, it will certainly the next patent."
1. Thermally assisted switching (TAS) MRAM :
- small current to heat MTJ -> higher sensitivity to magnetic field induced by above or below the MTJ
- TAS reduce current to induce magnetic field cur by half (5~10mA) than field induced magnetization switching (FIMS)
- STT is the best option for power consumption, though.
2. Most FPGA has SRAM for configuration memory
- For read operation, each memory point should be readable independently -> each point to drive transistor gate or lookup table input
- For writing operation, those memory operates in classic memory array -> speed limitation is the size of memory array.
- Increasing number of array improve speed and allows parallel loading
3. MRAM stack over CMOS logic in single chip
- Store information permanently (NVM-FPGA) -> simplify system level design
- Power saving advantage during standby mode
- Speed improvement as no need to load configuration data from external NVM. (which is the case for SRAM FPGA)
4. NVM register for MCU application
- Improve speed to reduce context of application
- Better soft error.