STMicroelectronics M93C56-WMN6P

Overview

M93C56-WMN6P from STMicroelectronics is a 2-Kbit serial EEPROM with MICROWIRE™ interface, configurable as 256 × 8-bit or 128 × 16-bit memory, operating from 2.5 V to 5.5 V supply and supporting up to 2 MHz clock frequency. It delivers byte/word/page write in ≤5 ms, features READY/BUSY signaling, and is used for parameter storage in industrial controllers and embedded system configuration.

For engineers reviewing the M93C56-WMN6P datasheet, M93C56-WMN6P pinout, M93C56-WMN6P application, or M93C56-WMN6P equivalent, key selection considerations include its dual x8/x16 organization, 4 million write cycles at 25°C, 200-year data retention, SO8N package compatibility, and MICROWIRE™ bus timing compliance per DS1077 Rev 20.

Technical Context

The M93C56-WMN6P implements a synchronous serial MICROWIRE™ interface with Chip Select (S), Serial Clock (C), Serial Data Input (D), Serial Data Output (Q), and Organization Select (ORG) control. Its internal architecture supports static operation (0 Hz minimum clock) and includes on-chip clock pulse counter to reject noise-induced instruction corruption.

Memory access uses start-bit–driven instruction framing (READ, WRITE, WEN, ERASE, etc.), with automatic address increment during sequential read and self-timed internal erase-before-write cycles. The ORG pin selects between 8-bit and 16-bit data width, directly mapping to physical memory layout without software translation.

Key Specifications

Pinout & Package

Package: SO8N (150 mil width), 8-pin small-outline integrated circuit, ECOPACK2-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with AT25020B-SSHL-T and BR24G02FJ-WE2, the M93C56-WMN6P uniquely offers hardware-selectable x8/x16 organization and READY/BUSY signaling on the Q pin-critical for deterministic timing in real-time embedded systems using MICROWIRE™-native controllers.

Availability

M93C56-WMN6P is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and smart energy meters requiring stable component supply across multi-year production cycles.

Supply support for M93C56-WMN6P 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and memory solutions for industrial, automotive, and consumer markets.

The M93C56-WMN6P belongs to ST's legacy MICROWIRE™ EEPROM product line, engineered specifically for reliable, low-pin-count nonvolatile storage in resource-constrained embedded systems where bus simplicity and hardware configurability outweigh protocol flexibility.

FAQ

What is the function of the DU pin on M93C56-WMN6P?

The DU (Do Not Use) pin is reserved for STMicroelectronics internal test purposes and contributes no functionality in normal operation. It may be left unconnected, tied to VCC, or tied to VSS per datasheet guidance. Leaving it floating is not recommended due to potential noise coupling, but no electrical damage occurs if done inadvertently.

Can M93C56-WMN6P operate at 1.8 V?

No. The M93C56-WMN6P is the -W variant, specified for 2.5 V to 5.5 V operation only. For 1.8 V compatibility, the -R variant (e.g., M93C56-RMN6TP) must be used. Attempting to power the -W part below 2.5 V results in undefined behavior, failed writes, and possible data corruption due to insufficient internal voltage margin.

How does the ORG pin affect memory addressing in practice?

When ORG is high (≥0.7×VCC), the device operates in x16 mode: addresses 0x00–0x7F select 128 words (each 16 bits wide). When ORG is low (≤0.3×VCC), it operates in x8 mode: addresses 0x00–0xFF select 256 bytes. The same physical memory array is accessed - only the interpretation of address width and data width changes, requiring matching firmware configuration.

Is the READY/BUSY signal electrically compatible with 3.3 V logic inputs?

Yes. The Q pin outputs VOH ≥0.9×VCC and VOL ≤0.1×VCC under load, making it fully compatible with standard 3.3 V CMOS inputs when VCC = 3.3 V. When VCC = 5 V, VOH ≈ 4.5 V - a level-shifter or series resistor may be needed for direct connection to 3.3 V-only inputs, though many modern MCUs tolerate 5 V-tolerant inputs on Q.