Maintain integrity and privacy for your critical information using AT25M02 and STM32F410RB

EEPROM 4 Click is based on the AT25M02, an SPI serial EEPROM from Microchip, with a memory cell density of 2 Mbits. The EEPROM density is usually expressed in bits, so exactly 2,097,152 bits are organized in units or words of 8 bits, which gives 262,144 bytes of data memory. Furthermore, the EEPROM is organized into so-called pages. One page holds 256 bytes, and there are 1024 pages (1024 pages x 256 bytes = 262,144 bytes total). Having insight into how the memory cells are organized is important for write and erase operations. The SPI pins are routed to the mikroBUS™, making communication easy and straightforward. The SPI can be clocked as high as 5MHz, providing a fast throughput for the data transfer. A dedicated #HOLD pin is routed to the PWM pin of the mikroBUS™. When the communication with the click board™ is initiated by setting the CS pin to a LOW logic state, it is possible to pause the serial data transfer without

resetting the communication if the #HOLD pin (PWM pin on the mikroBUS™) is set to a LOW logic state. To resume the communication, setting this pin to a HIGH logic state while the SCK is still running is enough. Once the HOLD is initiated, the state of the SCK line is irrelevant, and any serial data input will be ignored. This pin is pulled HIGH by the onboard resistor. A dedicated #WP write protect pin puts the device into the hardware write protect mode. This pin is routed to the RST pin of the mikroBUS™. Hardware write-protect works with the Write Protect Enable (WPEN) bit of the Status Register. When this bit is set to 1, and the #WP pin is set to a LOW logic state, the device will ignore any attempt to write to the Status Register and the EEPROM memory regions selected by the Block Write Protect bits of the Status Register (BP0 and BP1). WRSR instruction is used to write to the Status Register (01h). Again, WREN instruction should be executed first before 

attempting to write to Status Register. Once the WPEN bit is set to 1 and the RST has been pulled to a LOW logic state, setting the WPEN bit to 0 won’t turn off write protection as long as the #WP pin (RST) stays LOW. WPEN bit and the BP0 and BP1 bits are constructed as EEPROM cells, meaning that they are nonvolatile and will retain their states even after power is off. The #WP pin is pulled HIGH by the onboard resistor. As usual, the onboard SMD jumper labeled as VCCSEL is used to select the operating voltage between 3.3V and 5V. However, there’s the third position for this jumper, which sets the operating voltage to 1.8V. This is achieved thanks to the TC1015, a small 100 mA LDO from Microchip powered by the 5V rail. As always, MikroElektronika provides libraries that simplify and speed up working with this device. The provided application example demonstrates the functionality of the provided libraries and can be used as a reference point for own development.

Nucleo-64 with STM32F410RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.