Winbond Electronics Corporation W25M161AWEIT

Overview

W25M161AWEIT from Winbond is a 16Mb S-NOR + 1Gb S-NAND SpiStack® stacked flash memory IC supporting concurrent read-from-NOR and write/erase-to-NAND operations, operating at 1.8V, in an 8-pin WSON8 8x6mm package, used for code execution and high-speed data logging in embedded systems with real-time firmware updates.

For engineers reviewing the W25M161AWEIT datasheet, W25M161AWEIT pinout, W25M161AWEIT application, or W25M161AWEIT equivalent, key selection criteria include dual-die concurrency support, 1.8V Vcc compatibility, Industrial temperature range (−40°C to +85°C), WSON8 8x6mm footprint, and backward compatibility with standard SpiFlash® command set.

Technical Context

The W25M161AWEIT implements heterogeneous SpiStack® architecture combining one 16Mb S-NOR die and one 1Gb S-NAND die in a single package, enabling simultaneous code fetch from NOR while updating data in NAND without interrupting execution. It uses standard SPI (single I/O) interface with extended commands for die selection and concurrent operation control.

It supports Continuous Read mode by default (BUF=0), Industrial temperature grade (−40°C to +85°C), Halogen-Free/RoHS-compliant Green packaging (T suffix), and maintains full command-set compatibility with legacy SpiFlash® devices-no host driver changes required for basic read operations.

Key Specifications

Pinout & Package

W25M161AWEIT is housed in an 8-pin WSON8 (8×6 mm) package with exposed thermal pad. Pin functions follow standard SPI layout optimized for signal integrity and minimal board space.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stacked flash memory applications.

Compared with MX25L1633FMI-10G and MT29F1G08ABAEAWP-AIT:F, the W25M161AWEIT uniquely delivers concurrent NOR+NAND access in a single SPI package-reducing BOM count, eliminating NAND controller complexity, and enabling true real-time code/data coexistence without software workarounds.

Availability

W25M161AWEIT is available at Aetrix Electronics and suitable for industrial PLCs, automotive infotainment systems, and network edge gateways requiring stable component supply, long-term lifecycle assurance, and validated performance across −40°C to +85°C.

Supply support for W25M161AWEIT 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

Winbond Electronics Corporation is a Taiwan-based global supplier of specialty DRAM, mobile DRAM, Code Storage Flash, and TrustME® secure flash memory solutions.

The W25M SpiStack® product line was designed to eliminate multi-chip flash integration complexity by embedding heterogeneous NOR+NAND dies in standardized SPI packages for real-time embedded systems requiring both reliable code execution and high-density data storage.

FAQ

What is the exact memory composition of the W25M161AWEIT?

The W25M161AWEIT integrates two physically separate dies in one package: a 16Mb Serial NOR (S-NOR) die and a 1Gb Serial NAND (S-NAND) die. This heterogeneous stacking enables independent addressing and concurrent operation-NOR for fast random reads and NAND for high-throughput sequential writes-without shared bus arbitration or timing conflicts.

Does the W25M161AWEIT require special initialization or configuration to enable concurrent operation?

Yes-the W25M161AWEIT requires explicit die selection via the 0xC0 (Select Die 0) and 0xC1 (Select Die 1) commands before issuing read/write/erase operations. Concurrent operation is achieved by issuing a read command to Die 0 (S-NOR) while simultaneously sending a program/erase command to Die 1 (S-NAND), with no hardware handshake needed between dies.

Is the W25M161AWEIT pin-compatible with standard SPI flash devices like the W25Q16JV?

No-the W25M161AWEIT shares the same 8-pin WSON8 8x6mm physical package and SPI pinout (including /CS, CLK, DI, DO, /WP, /HOLD, VCC, GND), but its command set extends beyond standard SPI flash to include die-select and concurrent-operation opcodes. Host firmware must implement the extended instruction set to access both dies.

What does the "E" in W25M161AWEIT indicate in the part number?

The "E" in W25M161AWEIT specifies the package variant: WSON8 8x6mm (also denoted ZE). The "T" suffix confirms Green (halogen-free, RoHS-compliant) packaging and Continuous Read mode enabled by default (BUF=0), while "I" denotes Industrial temperature grade (−40°C to +85°C).

Can the W25M161AWEIT be used in systems that only support Quad SPI (QSPI) interfaces?

No-the W25M161AWEIT supports only standard single-I/O SPI (not QSPI or Octal SPI). It does not respond to quad-read commands (e.g., 0x6B) or have QSPI-specific registers. Systems requiring QSPI must use discrete QSPI NOR or alternative stacked solutions with native QSPI support, such as Winbond's W25Mxx2W series with QSPI-enabled variants.