OnSpecxSil 261 – Hi-Speed External USB Hard Disk Drive and CompactFlash Controller




OnSpec’s xSil 261 USB to UDMA4 CF or HDD Controller is the world’s first UDMA 4 enabled CF controller. It also can interface with Hard Disk Drives to provide a compelling external storage solution. The firmware has built-in support for Microsoft’s PD-DRM technology in addition to providing an SHA-256 based authentication protocol for implementing secure access to the Hard Disk Drive.

OnSpec offers reference designs, firmware, drivers, and manufacturing test software to make product development easy. OnSpec’s technology provides optimum throughput and superior flash media compatibility




·         Supports HDD IDE (upto ATA-7)  UDMA Modes 0..4, MDMA Modes 0..2, PIO Modes 0..4

·         Supports CompactFlash media (flash based and hard disk based)

·         Full Speed USB (USB1.1) and Hi-Speed USB (USB 2.0), Bus powered.

·         Compatible with Microsoft WinXP, WinME, Win2K, SP3, Apple OS X and Linux Multi-Lun Mass Storage Class Drivers

·         Win2K, Win98/98SE and Apple OS8.6 and OS9 Multi-LUN Mass Storage Class Drivers Available

·         Single chip with integrated USB 2.0 PHY

·         Optional Secure partition capability based on SHA-256 algorithm

·         Serial port

·         Two General Purpose Timers

·         Watchdog Timer

·         16 bit RISC Processor

·         Onboard ROM contains BIOS and Application code.

·         Programmable IOR and IOW widths

·         Optimum hardware controlled transfer for speed and scalability

·         48-pin 7mm x 7mm QFP package




Functional Description

The xSil 261 is designed to connect an IDE device, CompactFlash or Microdrive  to USB. It contains the following:100-pin 16mm x 16mm QFP package

·         48-pin 9mm x 9mm LQFP package

·         Single chip with integrated USB 2.0 PHY

·         Serial EEPROM port

·         IDE/ CFTM interface

·         Serial port

·         Two General Purpose Timers

·         Watchdog Timer

·         16 bit Processor

·         Internal RAM for supporting enhancements

·         ROM with BIOS and Application code.

·         Programmable Read and Write widths

·         PD-DRM support to report unique serial number

·         Optimum hardware controlled transfer for speed and scalability

·         Supports Hard drives of up to 2048GB (2TeraBytes)

·         Supports CompactFlash UDMA Modes 0..4, MDMA Modes 0..2, PIO Modes 0..6

·         Supports IDE (upto ATA-7)/ UDMA Modes 0..4, MDMA Modes 0..2, PIO Modes 0..4

·         Supports IBM, Seagate, Hitachi and Magicstor Hard disk based CF media

·         ROM has built in support for SHA-256 based authentication

·         Supports upto ATA-7, UDMA Modes 0..4, MDMA Modes 0..2, PIO Modes 0..4

Ordering Information


Part Number



xSil 261-G

USB 2.0 UDMA CF/ HDD Read Write Controller

48 LQFP  (RoHS Compliant)


Technical and Design-in Information

Contact: sales@siliconapps.com

Design Support (Will be provided by OnSpec upon request)

    • Read/Write Performance Testing (Software Release Notes)

    • USB IF Certification Lab Report Summary

    • IBIS Models (Available on request)

    • Qualification Report

    • BIOS Boot Over USB Compatibility Testing Report

    • Embedded OS Compatibility Testing with XXXXXX MSC Driver

Available from OnSpec under Software License Agreement (SLA):

  • Click Wrap SLA Agreement for Object Code on OnSpec Website

  • Manufacturing Utilities

  • Software Release Notes (Important for Attribute Bit Settings and Descriptions)

  • Software Test Report (Matrix of OS and PC Chipset Testing)

  • Windows 2000 and Multi-LUN Drivers

  • Email Notification of New Firmware Object Code Downloadable Over the OnSpec Secure Website


Information in this document is provided in connection with OnSpec Electronic products. No license, express or implied, by estoppels or otherwise, to any intellectual property rights is granted by this document. Except as provided in OnSpec Electronic’s Terms and Conditions of Sale for such products, OnSpec Electronic assumes no liability whatsoever, and OnSpec Electronic disclaims any express or implied warranty, relating to sale and/or use of OnSpec Electronic products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement or any patent, copyright or other intellectual property right.

OnSpec Electronic products are not intended for use in medical, life saving, or life sustaining applications.


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Download: Product Sheet PDF Size=64KB