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Renesas AT45DB321D-MWU-SL955
- Part No.:
- AT45DB321D-MWU-SL955
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
AT45DB321D-MWU-SL955.pdf
- Description:
- IC FLASH 32MBIT SPI 66MHZ 8VDFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,662
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Product details
Overview
AT45DB321D-MWU-SL955 from Microchip Technology (acquired Atmel) is a 32Mb serial DataFlash memory IC with SPI-compatible RapidS interface, 512/528-byte configurable page size, dual 512/528-byte SRAM buffers, and industrial temperature support. It enables high-speed code shadowing and in-system reprogrammability in embedded controllers requiring low-pin-count, low-voltage (2.5V–3.6V), and low-power nonvolatile storage.
For engineers reviewing the AT45DB321D-MWU-SL955 datasheet, AT45DB321D-MWU-SL955 pinout, AT45DB321D-MWU-SL955 application, or AT45DB321D-MWU-SL955 equivalent, key selection criteria include page-size flexibility (512 vs. 528 bytes), continuous array read up to 66MHz, sector lockdown security, and dual-buffer pipelined write capability for real-time data logging.
Technical Context
The AT45DB321D-MWU-SL955 implements a sequential-access flash architecture with two independent 512/528-byte SRAM buffers, enabling concurrent buffer fill while main memory is being reprogrammed. Its RapidS serial interface supports SPI modes 0 and 3 at up to 66MHz, with hardware-managed RDY/BUSY signaling via open-drain output.
Memory organization comprises 8,192 pages (512 or 528 bytes each), grouped into 64 sectors with hierarchical erase granularity: page (512B), block (4KB), sector (64KB), and full chip (32Mb). Page programming includes built-in erase or no-erase variants, both self-timed and controlled via CS edge transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory capacity | 32Mb (34,603,008 bits), organized as 8,192 pages of 512 or 528 bytes - enables flexible firmware partitioning and partial updates without full chip erase. |
| Interface speed | Up to 66MHz SCK for continuous array read (0BH/E8H opcodes) - supports real-time streaming from flash without CPU intervention. |
| Supply voltage | 2.5V–3.6V single supply - eliminates need for level shifters in 3.3V microcontroller systems and simplifies power design. |
| Active/standby current | 7mA typical read current, 25µA standby, 15µA deep power-down - extends battery life in portable and energy-sensitive applications. |
| Erase endurance | 100,000 program/erase cycles per page - ensures long-term reliability for frequently updated data log or configuration storage. |
| Data retention | 20 years at 85°C - meets industrial-grade longevity requirements for unattended equipment and infrastructure deployments. |
| Security features | 128-byte security register (64-byte user programmable + 64-byte unique ID), sector lockdown, and hardware WP pin - provides tamper-resistant firmware and credential storage. |
Pinout & Package
AT45DB321D-MWU-SL955 is packaged in an 8-pin SOIC (Small Outline Integrated Circuit) with standard 150-mil body width and RoHS-compliant green finish. Pin 1 is marked by a notch or dot; pin numbering follows counter-clockwise convention from top-left when viewed from top.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable signal; falling edge initiates command sequence, rising edge terminates operation and triggers self-timed execution. |
| SCK | Serial Clock | Input clock controlling data transfer timing; commands, addresses, and data latched on rising edge; SO data valid on falling edge. |
| SI | Serial Input | Command, address, and data input line; all instructions shifted in MSB-first via SI during CS low. |
| SO | Serial Output | Open-drain output for read data and status; tri-stated when CS is high; requires external pull-up resistor. |
| WP | Write Protect | Hardware-level sector protection override; low state blocks all program/erase operations on protected sectors regardless of software settings. |
| RESET | Reset | Active-low asynchronous reset; terminates ongoing operation and returns internal state machine to idle; internally pulled high. |
| RDY/BUSY | Ready/Busy Indicator | Open-drain output driven low during self-timed operations (program/erase/buffer transfers); used for polling or interrupt-driven flow control. |
| VCC / GND | Power Supply / Ground | Single 2.5V–3.6V supply pair; decoupling capacitor required near VCC pin to suppress switching noise during high-speed reads. |
Key Features
| Feature | Design Value |
|---|---|
| Dual SRAM buffers (512/528 bytes) | Enables pipelined operation: host can load next data block into one buffer while flash array is programming the other - critical for uninterrupted data acquisition. |
| Configurable page size (512 or 528 bytes) | Factory-set 512-byte "power-of-two" mode simplifies address arithmetic and aligns with standard filesystem block sizes; 528-byte mode supports ECC metadata embedding. |
| Continuous array read (E8H/0BH/03H) | Eliminates per-page address overhead; internal address counter wraps across page boundaries with zero latency - ideal for boot code shadowing and audio playback. |
| Sector lockdown & security register | Allows permanent locking of designated sectors containing bootloader or cryptographic keys; 64-byte unique device ID enables secure device authentication and binding. |
| Flexible erase hierarchy | Supports granular updates: page erase (512B) for small config changes, block (4KB) for firmware modules, sector (64KB) for major revisions, chip erase for factory reset - minimizes wear and downtime. |
Applications
| Firmware Boot Storage | Data Logging in Remote Sensors |
|---|---|
|
Use Scenario: Microcontroller boots from external flash by copying application code into RAM before execution. IC Role / Device Role / Timing Role: Nonvolatile sequential-access memory providing fast, reliable code shadowing with continuous read capability up to 66MHz. Use Value: Eliminates need for parallel NOR flash; reduces PCB footprint and EMI via 4-wire SPI interface while maintaining boot performance comparable to legacy solutions. |
Use Scenario: Environmental sensor node records timestamped temperature/humidity readings over weeks without host intervention. IC Role / Device Role / Timing Role: High-endurance, low-power storage managing circular buffer writes using page-erase and buffer-to-memory programming. Use Value: Dual buffers allow background logging while host processor sleeps; 100K-cycle endurance ensures >10-year field life at 100 writes/day. |
| Secure Firmware Updates | Industrial HMI Configuration Storage |
|
Use Scenario: Field-deployed PLC receives encrypted firmware patches via wireless link and validates/authenticates before installation. IC Role / Device Role / Timing Role: Trusted storage for signed firmware images and cryptographic keys, leveraging sector lockdown and unique device ID. Use Value: Hardware-enforced write protection prevents rollback attacks; 128-byte security register stores immutable root-of-trust credentials. |
Use Scenario: Human-machine interface panel retains display calibration, language settings, and user preferences across power cycles. IC Role / Device Role / Timing Role: Low-voltage (2.5V–3.6V), low-standby-current (25µA) nonvolatile memory preserving configuration in battery-backed or energy-harvested systems. Use Value: Deep power-down mode (15µA) extends backup battery life to >5 years; page-level erase enables efficient parameter updates without full reflash. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Winbond W25Q32JVSSIQ | 32Mb Quad SPI NOR flash; 4-line I/O, 133MHz DTR mode; no SRAM buffers; fixed 4KB sectors; no sector lockdown. | Better random read performance for XIP; lacks pipelined write and hardware security - unsuitable for secure firmware update or real-time logging. | Select when code execution-in-place (XIP) is required and security/throughput trade-offs favor density and speed over flexibility. |
| Macronix MX25L3233FZBI-10G | 32Mb standard SPI NOR flash; 104MHz max clock; no dual buffers; 4KB/64KB/512KB erase blocks; software-controlled protection only. | Lower cost; adequate for static firmware storage but cannot match AT45DB321D-MWU-SL955's concurrent buffer operation or hardware WP independence. | Choose for cost-sensitive designs where sequential access speed and advanced security are secondary to basic storage functionality. |
Compared with W25Q32JVSSIQ and MX25L3233FZBI-10G, the AT45DB321D-MWU-SL955 uniquely delivers pipelined write throughput via dual SRAM buffers, hardware-enforced sector lockdown, and factory-configurable page size - making it optimal for real-time data acquisition and secure firmware management where timing predictability and tamper resistance are critical.
Availability
AT45DB321D-MWU-SL955 is available at Aetrix Electronics and suitable for firmware boot storage, remote sensor data logging, secure firmware updates, industrial HMI configuration storage, and embedded audio playback requiring stable component supply and long-term lifecycle support.
Supply support for AT45DB321D-MWU-SL955 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
Microchip Technology acquired Atmel in 2016 and maintains full product support, documentation, and manufacturing continuity for the AT45DB321D family.
The AT45DB321D belongs to Atmel's DataFlash® product line, designed specifically for embedded systems needing high-speed serial flash with integrated SRAM buffers and robust security - targeting applications where pin count, power efficiency, and in-system reprogrammability are primary constraints.
FAQ
What is the default page size configuration for AT45DB321D-MWU-SL955?
The AT45DB321D-MWU-SL955 is factory preconfigured for 512-byte pages, supporting "power-of-two" addressing (A21–A0) and simplified integration with standard filesystems and microcontroller bootloaders. The 528-byte mode is available via factory option but not enabled by default on this specific variant.
Does AT45DB321D-MWU-SL955 support SPI Mode 1 or Mode 2?
No, AT45DB321D-MWU-SL955 supports only SPI Modes 0 and 3, as defined by its RapidS serial interface specification. Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1) are fully compatible with standard SPI peripherals; Modes 1 and 2 are not electrically or functionally supported.
Can AT45DB321D-MWU-SL955 be used for Execute-in-Place (XIP) applications?
AT45DB321D-MWU-SL955 does not support true XIP due to its sequential-access architecture and lack of random-address capability. However, its continuous array read (up to 66MHz) enables efficient code shadowing - where firmware is streamed into RAM for execution - achieving comparable system-level performance without parallel bus overhead.
How is the RDY/BUSY pin used during a buffer-to-memory page program operation?
During a buffer-to-memory page program (e.g., opcode 83H/86H), the RDY/BUSY pin is driven low immediately after CS goes high and remains low for the entire self-timed duration (tEP, max 25ms). Host systems must poll this pin or configure an interrupt to detect completion before issuing subsequent commands - ensuring reliable timing-critical operation of AT45DB321D-MWU-SL955.
Is the security register in AT45DB321D-MWU-SL955 write-once or reprogrammable?
The 128-byte security register in AT45DB321D-MWU-SL955 is reprogrammable, with the 64-byte user-programmable section supporting multiple writes. However, once sector lockdown is activated for a given sector, that sector's contents become permanently read-only - a hardware-enforced restriction independent of the security register's programmability.
AT45DB321D-MWU-SL955 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 32Mbit
- Memory Organization:
- 512 Bytes x 8192 pages
- Memory Interface:
- SPI
- Clock Frequency:
- 66 MHz
- Write Cycle Time - Word, Page:
- 6ms
- Access Time:
- -
- Voltage - Supply:
- 2.7V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VDFN (8x6)
AT45DB321D-MWU-SL955 FAQ
1.How can I place an order for AT45DB321D-MWU-SL955 through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45DB321D-MWU-SL955 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AT45DB321D-MWU-SL955 reliable?
The price and inventory of AT45DB321D-MWU-SL955 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45DB321D-MWU-SL955 is usually 5 days.
3.What payment methods are accepted for AT45DB321D-MWU-SL955?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45DB321D-MWU-SL955 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45DB321D-MWU-SL955?
AT45DB321D-MWU-SL955 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45DB321D-MWU-SL955 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AT45DB321D-MWU-SL955?
For technical support, including AT45DB321D-MWU-SL955 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45DB321D-MWU-SL955 requirements.
6.How does Aetrix verify that AT45DB321D-MWU-SL955 is sourced from the original manufacturer or authorized distributors?
All AT45DB321D-MWU-SL955 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT45DB321D-MWU-SL955 meets industry standards.
7.What is the process for return or replacement of AT45DB321D-MWU-SL955?
All AT45DB321D-MWU-SL955 units undergo pre-shipment inspection (PSI). If there is an issue with AT45DB321D-MWU-SL955, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AT45DB321D-MWU-SL955 part is unused and in its original packaging.
Return procedure for AT45DB321D-MWU-SL955:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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