BY25Q256FSFIG(T)

Memory IC Overview

The BY25Q256FS is a 256M-bit Serial Peripheral Interface (SPI) NOR Flash memory manufactured by BYTe Semiconductor. It supports Standard, Dual, Quad SPI, and QPI modes with Double Transfer Rate (DTR) read capabilities. The device operates on a single supply voltage ranging from 2.7V to 3.6V and functions within a temperature range of -40°C to +85°C. Key electrical parameters include a maximum active current of 25mA and a power-down current of 5µA. Typical performance metrics feature a page program time of 0.6ms, sector erase time of 50ms, block erase times of 0.15s/0.25s, and chip erase time of 80s. The architecture includes uniform 4KB sectors and 32KB/64KB blocks.

Memory IC Feature Summary

• Supports multiple interface modes including Standard SPI, Dual SPI, Quad SPI, and QPI with Double Transfer Rate (DTR) for high-speed data transfer.
• Features flexible memory architecture with uniform 4KB sectors and 32KB or 64KB blocks for efficient erasure operations.
• Includes comprehensive write protection mechanisms such as hardware /WP pin control, software/hardware lock bits, and three 512-byte security registers with OTP locks.
• Enables Execute-In-Place (XIP) operation allowing continuous reads with wrap modes of 8, 16, 32, or 64 bytes.

Memory IC Applications

• Embedded systems requiring direct code execution from flash memory
• Firmware storage for microcontrollers and IoT devices
• Industrial control systems operating in wide temperature ranges
• Consumer electronics needing reliable non-volatile data retention

Memory IC Procurement Notes

Verify the specific package variant required, as the datasheet lists 8-pin SOP 208mil, 8-pad WSON 5x6mm, 8-pad WSON 6x8mm, and 16-pin SOP 300mil. Confirm that the ordering suffix matches the desired physical footprint and lead time specifications provided by the manufacturer. Ensure compatibility with host system voltage levels within the 2.7V to 3.6V range before integration.

Memory IC Selection Notes

Select this component when a 256M-bit capacity is required with support for high-speed Quad I/O and QPI interfaces. It is suitable for applications demanding XIP functionality and robust data protection features. Consider the available package options based on board space constraints. Verify that the host controller supports the necessary SPI modes and address lengths (3-byte or 4-byte) for proper initialization and operation.

Memory IC Part Context

The BY25Q256FS belongs to the BY25Q256 series of serial NOR flash memories from BYTe Semiconductor. This series is designed for general-purpose storage applications requiring high reliability and speed. The device shares architectural similarities with other industry-standard serial flash parts but offers specific feature sets like DTR read and advanced block protection defined in its datasheet.

Memory IC Replacement Considerations

Publicly confirmed substitute part numbers are not explicitly listed in the provided source material. When evaluating alternatives, ensure the replacement supports 256M-bit density, 2.7V-3.6V operation, and compatible SPI/QPI command sets. Package dimensions must be verified if a pin-compatible swap is intended.

Memory IC FAQ

How does the device handle addressing for capacities above 128M-bit?

The BY25Q256FS supports both 3-Byte and 4-Byte Address Modes. For 3-Byte mode, an Extended Address Register is used to access addresses above 16MB. In 4-Byte Address Mode, the extended register is not necessary, simplifying access to the full 256M-bit array.

What is the function of the /HOLD and /RESET pins?

When the Quad Enable (QE) bit is cleared, the pin can function as /HOLD to pause serial communication without stopping internal operations, or as /RESET to reset the device. If QE is set, the pin acts as IO3 for data input/output in Quad or QPI modes.

Can the device operate in QPI mode immediately after power-up?

No. Upon power-up or hardware reset, the device defaults to Standard/Dual/Quad SPI mode. To enter QPI mode, the Quad Enable (QE) bit in Status Register 2 must be set, followed by issuing the 'Enter QPI' instruction.