Canaan Avalon Nano3S -A3197S ASIC Reverse Engineering Report
The first public reverse-engineering of Canaan's A3197S Bitcoin mining ASIC
Date: June 5, 2026
Conducted by: Nikos
ASIC: Canaan A3197S (Avalon-Nano class) — 10 SHA-256 engines per chip
Host platform: Canaan Avalon Nano 3s (12× A3197S, Kendryte K230D dual-core RISC-V)
Stock Firmware: Avalon Nano 3s release 2025061101 (June 2025)
Test Firmware: TNA-OS (custom mining stack built on the cracked protocol)
Board Revision: MM-NANO3S-V0.2
Executive Summary
To the author's knowledge, this is the first time anyone has publicly reverse-engineered Canaan's A3197S Bitcoin mining ASIC — the chip at the heart of the Avalon Nano 3s and related Avalon-Nano-class hardware.
The A3197S is closed silicon. Its host-to-chip mining protocol is undocumented; the second RISC-V core that drives it ships encrypted on flash; and there is no published information describing how the chip is brought up, configured, fed work, or how it reports results. Every existing deployment of this ASIC runs the vendor's closed stack and nothing else.
This study cracked that wall: the complete A3197S serial mining protocol was recovered — chain enumeration, per-chip configuration and calibration, the high-speed bus bring-up, work dispatch, version-rolling (AsicBoost) setup, and the nonce-report format the chip returns. With the protocol understood, a branch of firmware (TNA-OS) was written to drive the chips directly, independently of any vendor software.
FULL REPORT AVAILABLE HERE :
https://github.com/CryptoIceMLH/Nano3S
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