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SEGGER emFile File System
SEGGER SEGGER

emFile File System

Embedded Software

Embedded file system supporting FAT12/16/32 and exFAT with journaling for power-fail safety, wear leveling for NAND/NOR flash, and broad media driver support. GSAS India partner.

Formats

FAT12/16/32, exFAT

Reliability

Journaling, power-fail safe

Flash Support

NAND, NOR, DataFlash

Media

SD/MMC, USB MSD, SPI Flash

Wear Leveling

Static + dynamic

License

Royalty-free

Authorized SEGGER partner
Local FAE & application engineering
Hands-on training & integration
Manufacturer warranty

About emFile File System

SEGGER emFile is a fail-safe embedded file system that brings reliable storage management to microcontroller-based products where data integrity cannot be compromised by unexpected power loss or flash media degradation. Supporting FAT12, FAT16, FAT32, and exFAT formats, emFile provides interoperability with PC and host systems while its journaling engine ensures that file system metadata remains consistent even when power is lost mid-write, a non-negotiable requirement for data loggers, medical devices, industrial controllers, and metering equipment deployed across India’s power and utility infrastructure.

emFile overview

Type
Embedded file system
Standards / Classes
FAT12/16/32, exFAT
Footprint
Journaling, static + dynamic wear leveling
License
Royalty-free

Supported Storage Media

Media TypeInterfaceTypical Use Case
SD / SDHC / SDXCSPI or native SDData logging, portable storage, configuration
eMMCParallel / HS200High-capacity onboard storage
NAND FlashParallel / ONFIIndustrial data recorders, large log files
NOR FlashSPI, QSPI, Octal-SPIFirmware storage, configuration, code-execute-in-place
DataFlashSPILow-cost serial storage (Atmel/Renesas)
USB Mass StorageUSB (via emUSB-Host)External drives, USB sticks
RAM DiskInternal SRAMTemporary file operations, test environments

Wear Leveling

Wear leveling algorithms, both static and dynamic, extend the operational life of NAND and NOR flash media by distributing write and erase cycles evenly across the storage array:

  • Dynamic wear leveling: distributes writes across free blocks, ensuring frequently updated data does not burn out a small set of erase blocks
  • Static wear leveling: periodically relocates cold (rarely updated) data so that all blocks age uniformly, maximizing total flash endurance
  • Bad block management: automatic detection and remapping of failed NAND blocks with transparent fallback to spare blocks

These algorithms are critical for products with 10+ year field lifetimes where flash endurance directly determines product reliability.

Journaling and Power-Fail Safety

emFile’s journaling engine writes metadata changes to a transaction log before committing them to the file system. If power is lost during a write, the journal is replayed at next mount to restore a consistent state. This provides true power-fail safety without requiring the application to implement its own recovery logic, essential for energy metering, medical device recording, and industrial process logging.

SEGGER Ecosystem Integration

The royalty-free licensing model keeps bill-of-materials costs predictable for high-volume production, and emFile integrates cleanly with other SEGGER middleware, emUSB-Host for USB storage access, emNet for networked file serving, and embOS for thread-safe multi-tasking file operations. This composability means teams can add persistent storage to an existing SEGGER-based design without introducing a separate vendor’s file system and the integration risk that comes with it.

Common questions about emFile File System

What is SEGGER emFile?
SEGGER emFile is a fail-safe embedded file system supporting FAT12, FAT16, FAT32, and exFAT formats. Its journaling engine keeps file system metadata consistent through unexpected power loss, and it supports wear leveling for NAND and NOR flash media.
Is emFile royalty-free?
Yes. emFile is licensed royalty-free, which keeps bill-of-materials costs predictable for high-volume production runs.
Which SEGGER middleware for power-fail-safe data logging?
emFile is SEGGER's file system for power-fail-safe storage, using journaling so metadata stays consistent if power is lost mid-write, a requirement for data loggers, medical devices, and metering equipment.
Can I buy SEGGER emFile in India?
GSAS Micro Systems, SEGGER's authorized engineering partner in India, offers emFile with competitive pricing and short lead times. Request a quote for current INR pricing with GST-compliant invoicing.
What storage media does emFile support?
emFile supports SD/SDHC/SDXC, eMMC, NAND flash, NOR flash, DataFlash, USB mass storage (via emUSB-Host), and RAM disk, covering the media types used across data loggers, industrial recorders, and firmware storage.

Interested in emFile File System?

Get pricing, an evaluation unit, or a technical consultation from our application engineers.

Request a Quote Demo