Encryption for XIP and MMIO external memories

US10157283B2 · kind B2 · utility

Assignee

• Cypress Semiconductor Corporation · US

Inventors

• Hans Van Antwerpen · Mountain View, US
• Jan-Willem van de Waerdt · San Jose, US

Key dates

• Filing date: Dec 21, 2017
• Grant date: Dec 18, 2018
• Expiry date: Dec 21, 2037

Classification

• Technology area (CPC —): General

Abstract

Techniques for multiplexing between an execute-in-place (XIP) mode and a memory-mapped input/output (MMIO) mode for access to external memory devices are described herein. In an example embodiment, an IC device comprises a serial interface and a controller that is configured to communicate with external memory devices over the serial interface. The controller comprises a control register and a cryptography block. The control register is configured to indicate an XIP mode or a MMIO mode. The cryptography block is configured to encrypt and decrypt XIP data transfers to and from a first external memory device in the XIP mode, and to encrypt and decrypt MMIO data transfers to and from a second external memory device in the MMIO mode.