31.1 Overview

The TrustRAM (TRAM) is the controller interface for a 256-byte security RAM. This RAM is intended for volatile secret data. The TRAM is capable of performing address map scrambling and data scrambling for write and read access to the security RAM.

The TRAM can execute two automated tasks that are triggered by external events: remanence prevention and erase. When a remanence periodic event occurs, the physical data stored in the RAM is inverted to prevent physical “burn-in” signatures. When a tamper event occurs, the TRAM executes a full erase of the control signals and the data in the security RAM. Both automated tasks do not require CPU interaction and can be performed in all sleep modes.