Secure Cortex-M3 flash microcontroller with XiP QuadSPI interface

February 06, 2017 // By Graham Prophet
Maxim Integrated has posted outline details of the MAX32552, a secure flash microcontroller based on an ARM Cortex-M3 core. Maxim's DeepCover embedded security solutions are designed to conceal sensitive data under multiple layers of advanced physical security to provide the most secure key storage possible.


The microcontroller is intended to provide an interoperable, secure, and cost-effective solution to build new generations of trusted devices such as mobile chip and pin pads. The MCU is based on a Cortex-M3 processor with 1 MB of embedded flash, 384 kB of system RAM, and 8 kB of battery-backed AES self-encrypted NVSRAM. In addition to a high-performance QSPI interface for secure code execution (XiP: execture in place) and data storage, it includes most of the essential functions of mobile POS terminal including a cryptographic engine, a true random number generator, battery-backed RTC, environmental and tamper detection circuitry, a magnetic stripe reader, a smart card controller with embedded transceiver to directly support 1.8V, 3.3V, and 5V cards, and an integrated secure keypad controller. It also provides a seamless interface to monochrome graphic displays and includes an array of peripherals, SPIs, UARTs, DMA, ADC, and DAC, that add flexibility to control and differentiate the system design.


The feature list for the device includes;

108 MHz core operating frequency through PLL

1MB dual-bank flash memory with cache

384kB system SRAM

8KB AES self-encrypted NVSRAM

Security features facilitate system-level protection

Secure boot loader with public key authentication

AES, DES and SHA hardware accelerators

Modulo arithmetic hardware accelerator (MAA) supporting RSA, DSA, and ECDSA

8-line secure keypad controller

Hardware true random-number generator

Die shield with dynamic fault detection

6 external tamper sensors with independent random dynamic patterns

256-bit flip-flop-based battery-backup AES key storage

Temperature and voltage tamper monitor

Real-time clock

Integrated peripherals reduce external component count

Triple-track magnetic stripe head interface

Two ISO 7816 smart card UART with one that integrates a ISO7816 transceiver (1.8V, 3V, and 5V)

USB 2.0 device with internal transceiver and dedicated PLL

3 SPI ports, 2 UART ports, and 2 I²C controller

6 timers, 4 with PWM capability

Up to 64 general-purpose I/O pins

2-channel, 10-bit ADC and 1-channel, 8-bit DAC

Monochrome LCD controller

4-channel DMA controller