USB-TO-GPIO datasheet(19/50 Pages) TI1

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4.1

Introduction

Chapter 4

SLLU093 – August 2006

Firmware Versioning Scheme

This chapter briefly describes the firmware versioning scheme for the USB interface

adapter. Understanding the versioning scheme is critical for using the device in the

preset configuration. This topic is important for those who would like to make a custom

implementation of firmware or to understand how the firmware version is validated by

the host client software.

The firmware can be no more than 8K bytes. This limits the amount of functionality that any single

firmware image can have. All the functions needed for every application could not possibly be

implemented in this space. In order to make the device extensible and to allow its use in many

applications, it was designed in a way for a host application to reprogram the device with its own custom

firmware whenever needed.

For example, some end devices may require protocol X to send and receive data, but the standard

firmware does not support protocol X. In this case, the programmer of the GUI software that supports this

end device writes custom firmware that conforms to the rules in Section 4.2. At run time, the GUI software

finds the USB interface adapter and retrieves its firmware version number. If the version number is not

compatible with the protocols needed, the GUI software then reprograms the device with its own version

of firmware so that it can use it.

If all GUI software complies with this versioning system, then the same hardware can be reused for many

applications without inhibiting other compliant software. This also ensures that all implementations will

be backward compatible with older GUI software.

SLLU093 – August 2006

Firmware Versioning Scheme

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