STMicroelectronics STEVAL-SCM001V1

Overview

STEVAL-SCM001V1 from STMicroelectronics is a USB-connected RTC demonstration dongle built around the M41T62 real-time clock IC and ST72651AR6 8-bit microcontroller, supporting dual-mode operation (RTC monitoring and USB mass storage), capacitor-based or regulated RTC backup power, and real-time parameter control via GUI.

For engineers reviewing the STEVAL-SCM001V1 datasheet, STEVAL-SCM001V1 pinout, STEVAL-SCM001V1 application, or STEVAL-SCM001V1 equivalent, this board enables rapid validation of M41T62 timekeeping accuracy, ST7 USB interface implementation, RTC supply mode switching, and GUI-driven configuration in embedded timing subsystems.

Technical Context

The board implements a complete USB-to-RTC interface using the ST72651AR6 MCU as a bridge: it handles USB enumeration (full-speed), I²C communication with the M41T62 (SCL/SDA routed to PF5/PF6), and dynamic selection between V_DD regulator output and external capacitor for RTC V_CC backup. The M41T62 provides 32.768 kHz crystal-based timekeeping with SQW output and IRQ/OUT alarm functionality.

Hardware design includes on-board 12 MHz oscillator for ST7 core timing, 32.768 kHz tuning-fork crystal for RTC precision, USB-B connector with ESD protection diodes (D1/D2), NAND flash memory (U2) for mass storage emulation, and six user LEDs (LD1–LD6) for status indication across modes.

Key Specifications

Availability

STEVAL-SCM001V1 is available at Aetrix Electronics and suitable for RTC validation, USB firmware development, and embedded timekeeping subsystem prototyping requiring stable component supply, traceable sourcing, and lifecycle continuity.

Supply support for STEVAL-SCM001V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, MEMS, power devices, and silicon carbide solutions for industrial, automotive, and consumer applications.

This evaluation board belongs to ST's STEVAL (ST Evaluation) series-engineered to accelerate customer adoption of ST's timing, USB, and mixed-signal products through plug-and-play hardware, ready-to-run firmware, and intuitive PC software.

FAQ

Does STEVAL-SCM001V1 require external drivers on modern Windows systems?

No. The board uses standard USB CDC and Mass Storage Class descriptors. It enumerates natively on Windows 10/11, Linux (kernel ≥2.6), and macOS without proprietary drivers. The GUI application (provided by ST) runs on Windows only and communicates via HID over USB.

Can the M41T62 RTC be accessed directly via I²C without using the GUI?

Yes. The M41T62's SDA (pin 9) and SCL (pin 10) are exposed on test points TP1 and TP2, and also routed to ST72651AR6 pins PF6 and PF5. Engineers may bypass the GUI and implement custom I²C firmware on the ST7 or connect an external master controller to these pins.

What is the accuracy specification of the onboard RTC when using the 32.768 kHz crystal?

The M41T62 achieves ±5 ppm typical accuracy at 25°C with the provided 32.768 kHz crystal (XO2), 6 pF load capacitors (C8/C9), and proper PCB layout. Accuracy degrades to ±20 ppm over –40°C to +85°C per M41T62 datasheet specifications.

Is the NAND flash memory on STEVAL-SCM001V1 field-replaceable or configurable?

No. The Micron MT29F16G08AAC NAND flash (U2) is soldered and pre-programmed with ST's mass storage firmware. Its capacity (16 MB) and file system (FAT16) are fixed; reprogramming requires ST-provided tools and is not supported for end-user modification.