STMicroelectronics M95256-RCS6TP/A

Overview

M95256-RCS6TP/A from STMicroelectronics is a 256-Kbit serial SPI EEPROM organized as 32,768 × 8 bits, operating from 1.8 V to 5.5 V supply with 20 MHz clock support, 64-byte page size, and enhanced write protection (quarter/half/whole array). It features an additional lockable 64-byte Identification page and is qualified for industrial temperature range (−40 °C to +85 °C).

For engineers reviewing the M95256-RCS6TP/A datasheet, M95256-RCS6TP/A pinout, M95256-RCS6TP/A application, or M95256-RCS6TP/A equivalent, key selection criteria include supply voltage compatibility (1.8–5.5 V), SPI mode support (CPOL/CPHA = 0/0 or 1/1), identification page locking capability, write endurance (>4 million cycles), and ECOPACK2-compliant TSSOP8 packaging.

Technical Context

The device implements a standard SPI interface with dedicated HOLD and W signals enabling communication pause and hardware-based memory protection. Its status register (SRWD, BP1/BP0, WEL, WIP) supports configurable software/hardware write lock granularity down to quarter-array level.

Internally, it integrates high-voltage generation, ECC-enabled sense amplifiers, and page latches for reliable 5 ms byte/page writes. The Identification page (64 bytes) is accessible only via RDID/WRID instructions and can be permanently locked in read-only mode using LID instruction.

Key Specifications

Pinout & Package

Package: TSSOP8 (169 mil width), ECOPACK2-compliant, surface-mount, 8-pin thin shrink small outline package with exposed pad option per variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF321A-SSH-T and M95256-WDW6TP, M95256-RCS6TP/A uniquely balances wide-voltage operation (1.8–5.5 V), industrial temperature range, and secure lockable Identification page-making it optimal for resource-constrained, safety-aware embedded systems requiring both flexibility and data integrity.

Availability

M95256-RCS6TP/A is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter firmware storage, PLC I/O module configuration, and medical device parameter archiving requiring stable component supply, long-term obsolescence management, and ECOPACK2-compliant sourcing.

Supply support for M95256-RCS6TP/A 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.

M95256-RCS6TP/A belongs to ST's serial EEPROM product line, engineered specifically for robust, low-power, SPI-based nonvolatile storage in space- and power-constrained embedded systems demanding high reliability and secure configuration management.

FAQ

What is the function of the HOLD pin on M95256-RCS6TP/A?

The HOLD pin pauses ongoing SPI communication without deselecting the device or resetting internal state. When asserted low while Chip Select (S) is low and Serial Clock (C) is low, Q goes high-impedance and D/C are ignored. This enables MCU interrupt servicing or bus arbitration without aborting multi-byte transfers, preserving full transaction context across hold/resume cycles.

How does the Identification page differ from the main memory array?

The Identification page is a dedicated 64-byte region accessible only via RDID/WRID instructions-not through standard READ/WRITE commands. It supports permanent read-only locking via LID instruction, and its contents persist independently of main array erase/write cycles. This enables secure storage of calibration IDs, device serial numbers, or cryptographic keys that must remain immutable after commissioning.

Can M95256-RCS6TP/A operate reliably at 1.8 V with 20 MHz SPI clock?

Yes-M95256-RCS6TP/A is fully specified for 20 MHz operation across its entire 1.8 V to 5.5 V supply range. DC and AC parameters in DS4712 Rev 22 confirm tCLQV (clock-to-output delay) ≤ 30 ns and tCHSH (clock high/low times) ≥ 25 ns at 1.8 V, ensuring timing compliance with standard SPI peripherals even at minimum VCC.

What happens if Write Protect (W) is driven high while SRWD = 1?

When SRWD = 1 and W is high, the Status register remains writable-BP1/BP0 bits can still be modified via WRSR. Only when both SRWD = 1 *and* W is driven low does Hardware Protected mode activate, freezing BP1/BP0/SRWD bits permanently. Driving W high under SRWD = 1 restores full Status register write capability, allowing dynamic protection reconfiguration during field updates.