F40 Developers' Guide

Last modified May 17, 2016

The F40 family was previously known as the ALFAT. Please bear with us as we update ALFAT references to F40.


The F40 family of products are all based on the main processor: 

F40 SoC Processor

A number of off the shelf circuit boards containing the F40 Soc are available. Each board focuses on exposing one or more of the supported File System devices (SD Reader, USB storage clients) by adding physical connector(s). Current circuits include:

  1. F40 OEM Board - fully populated: 2 x USB ports, and SD Card socket.
  2. F40 SD Board - has SD Card socket
  3. F40 USB Board - populated with a full size USB port
  4. F40 SDR Board - An OEM board specifically designed for F40's SD Reader mode.

Communication between the F40 device and the controlling MCU can occur over UART, SPI, or I2C at high speeds. A library of F40 interface examples can be used to assist development.


The F40 Evaluation Kit creates a development/discovery platform that uses an USB to Serial cable to immediately start working with any of the F40 circuit boards; no external hardware is needed:


The latest firmware and a tool to load it are found at

  1. Firmware: http://www.ghielectronics.com/downloads/ALFAT/ALFAT(2.0.0).GHI
  2. Tools: http://www.ghielectronics.com/downloads/ALFAT/ALFAT_FirmwareUpdater.zip

Periodically, the support page for "File System" products should be checked for up to date information.

Instructions are found in the File System User Manual.

At its discretion, GHI Electronics may publish beta versions of F40 firmware. These releases are not posted until they are considered fully tested in-house, and are ready for field testing. They often have new features.  Interested customers may contact GHI Electronics (https://www.ghielectronics.com/contact) for other information.


The following sections lists some device speed that have been tested with F40. The tests were performed using the E command, which gives the internal access speed to the media. The full command used was:

Tested USB Drives

Brand/Model/Link Write Speed Read Speed Notes
Patriot Memory 4GB 2.30MB/Sec 1.93MB/Sec Test for 100MB in high speed mode
Patriot Memory 4GB 917KB/Sec 948KB/Sec Test for 10MB in full speed mode

Tested SD memory Cards

Brand/Model/Link Write Speed Read Speed Notes
Transcend 4GB Micro SD 4MB/Sec 7.2MB/Sec Test for 100MB


The F40 SoC physical dimensions are described by http://www.ghielectronics.com/downloads/model/LQFP64_10x10.pdf

Leave feedback about this document.
Let us know if the information presented here was accurate, helpful and if you have any suggestions.
Leave feedback about this document.
Let us know if the information presented here was accurate, helpful and if you have any suggestions.

* Indicates required fields.
This form is only for feedback not support.
Review our how to find information guide on locating helpful resources.