ACIM Macro - FeFET(PDK: GF28SLPe)

4-kb FeFET compute-in-memory macro with 64×64 crossbar array and on-chip 4-bit Flash ADC.

Overview

This chip implements a 4-kb FeFET-based compute-in-memory (CIM) macro fabricated in GlobalFoundries 28-nm HKMG FeFET process. It features a 64×64 crossbar array with on-chip 4-bit Flash ADCs for analog-to-digital conversion.

Key Results

  • Energy efficiency: 346.6 TOPS/W (9.5× improvement over prior 40-nm RRAM-CIM)
  • Inference accuracy: 89.1% on CIFAR-10 (VGG-8), close to 89.7% software baseline
  • Innovation: ISPP (Incremental Step Pulse Programming) scheme to reduce current variation

Publications

V. Garg, J. Jia, O. Phadke, S. Yu, “A 28-nm FeFET Compute-in-Memory Macro With 64×64 Array Size and On-Chip 4-Bit Flash ADC,” IEEE Solid-State Circuits Letters, 2025. [DOI]