Save important data easily with S25FL512S and STM32F091RC

Flash 4 Click is based on Infineon's S25FL512S, a 512 Mbit SPI Flash memory module. The Flash memory density is usually expressed in bits, so 512 Mbit of memory aligned in 8 bits long words translates to a capacity of 64 megabytes (MB). This memory module contains 256 sectors of 256 KB each. Furthermore, the memory is organized in 256KB sectors, allowing users to erase the whole sector only and write up to 512 bytes at a time. The advanced MirrorBit® technology allows storing two data bits in each memory array transistor (memory cell), effectively doubling the capacity of a single storage cell. The Eclipse™ architecture is responsible for the greatly improved erase and programming performance compared to other Flash modules of the previous generation. Due to a higher speed, an execute-in-place (XIP) and data shadowing are possible with the Flash 4 Click. The S25FL512S flash module supports the standard SPI interface, but it can also optionally use the Dual and Quad SPI interface, allowing the full data transfer rate of 80MB/sec. In addition, the flash module supports DDR read commands in all SPI modes, using both clock edges to transfer the data (data transfer is performed on both the rising and the falling edge of the clock). A typical communication procedure consists of sending a proper instruction (command) from the host MCU via the SPI interface, followed by either an address,

data, or both, and a response from the S25FL512S flash module, which can be either a stream of data or a single byte, depending on the command received. One of the key features of the S25FL512S is certainly the AutoBoot feature. It allows the module to automatically initiate the memory transfer from the predefined location (memory read operation) after the reset cycle. Considering a typical communication scenario, where the READ command followed by one or more address bytes need to be used, AutoBoot allows the host MCU to pull down the #CS (Chip Select) pin and start receiving a data stream over the SPI interface for as long as the #CS pin is held LOW, without any wasted cycles. As soon as the #CS pin is released, the S25FL512S returns to normal operation. The #WP write protect pin puts the device into the hardware write protect mode. A LOW logic level on this pin prohibits writing operations to the Block-Protection bits of the Status register. Locking down the Status Register will block changes of the Status Register Write Disable (SRWD) bit, which is required for the Write and Erase operations, effectively preventing the memory content changes. The pin is multiplexed with the IO2 function. Therefore, it is not available when Quad SPI is used. The #HOLD pin is used to hold the data transfer. When the Chip Select pin (#CS, routed to the mikroBUS™ CS pin) is set

to a LOW logic level, the data transfer will be put on hold when the LOW logic level of the serial clock coincides with the falling edge of the #HOLD pin. Similarly, resuming the data transfer will happen when the LOW logic level of the serial clock coincides with the rising edge of the #HOLD pin. The pin is multiplexed with the IO3 function. Therefore it is not available when Quad SPI is used. The SPI interface pins are routed to the mikroBUS™ so that the interfacing with the microcontroller unit (MCU) is easy and straightforward. Additional pins routed to the mikroBUS™ include the #WP/IO2 pin routed to the mikroBUS™ PWM pin and labeled as IO2 and the #HOLD/IO3 pin routed to the mikroBUS™ INT pin and labeled as IO3. There is also the RESET pin, routed to the RST pin of the mikroBUS™, which performs a reset of the Flash module, initiating an AutoBoot sequence if enabled. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

Nucleo-64 with STM32F091RC 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.