Start-Up Floadia Develops Prototype 7-Bit-Per-Cell Flash Chip Retaining Analog Data for 10 Years at 150°C

Floadia Corporation has developed a prototype 7-bit-per-cell flash memory chip that can retain analog data for ten years at 150°C by devising a memory cell structure and control method.

With the existing memory cell structure, the problem of characteristic change and variation due to charge leakage was significant, and the data retention was only about 100s.

The company will apply the memory technology to a chip that realizes AI inference operations with overwhelmingly low power consumption. This chip is based on an architecture called Computing in Memory (CiM), which stores neural network weights in non-volatile memory and executes a large number of multiply-accumulate calculations in parallel by passing current through the memory array. CiM is attracting attention as an AI accelerator for edge computing environments because it can read a large amount of data from memory and consumes much less power than conventional AI accelerators that perform multiply-accumulate calculations on CPUs and GPUs.

This memory technology is based on SONOS-type flash memory chips developed by the company for integration into microcontrollers and other devices. The firm made innovations such as optimizing the structure of charge-trapping layers, i.e. ONO film, to extend the data retention time when storing 7 bits of data. The combination of 2 cells can store up to 8 bits of neural network weights, and despite its small chip area, it can achieve a multiply-accumulate calculation performance of 300TOPS/W, exceeding that of existing AI accelerators.