Maintain integrity and privacy for your critical information using AT25M02 and PIC18F57Q43

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.

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.