Abstract
The lightweight and reliability of physical unclonable function (PUF) is critical for IoT security. In this work, we propose a strong PUF based on spin-transfer torque magnetoresistive random-access memory (STT-MRAM). For the first time, we adopt a logic-in-memory (LIM) structure known as Computational Random Access Memory (CRAM) in order to promote massive parallelism and low area overhead. As a result, the proposed PUF macro occupies 2960.4 μm2 in total, 5.77 μm2 per cell, and presents the high bit rate of 1.42 Gb/s. In addition, we introduce TRIM circuit and algorithm to the response generation process, and develop two TRIM algorithms to optimize its reliability. he proposed PUF presents an excellent average intra-chip Hamming distance of 0.288% under the temperature range from -10℃ to 150℃. The PUF also achieves an inter-chip Hamming distance of 50.003% and generates 22N/3 challenge-response pairs (CRPs), which surpass other state of the art MRAM strong PUFs. This work provides a new strong PUF solution for resource-limited System on chip (SoC) chips for edge applications.