3.6.3.1 Overview and Components of the Wireless Update Feature
As described in Section 3.6.3, the wireless update feature allows wireless updates of the eZ430-Chronos firmware. One of the requirements for the wireless update implementation is to use as little flash memory as possible. Therefore, a lightweight radio protocol was developed, which resides in the BSL flash area of the CC430. The software that handles the LCD progress information and the flash memory programming is downloaded over the air and executed in RAM. Components of the wireless update software include:
- Radio protocol in BSL memory area of the CC430 (eZ430-Chronos wrist module)
- The "RAM-based update software" contains LCD and flash write routines (transferred from PC to RAM of the wrist module)
- Radio protocol stack of the wireless update on RF access point (CC1111 or MSP430F5509 + CC1101)
- PC application supporting the update functionality
The update procedure works as follows:
- Wireless update functionality is activated in the PC application, after a valid flash image is selected
- RF access point is ready and awaits a request from a Chronos module
- Wireless update is activated on the Chronos module
- Chronos module downloads LCD and flash write routines (RAM-based update software) from the PC into the RAM of the CC430. The Chronos module displays "rAN" (=RAM).
- Chronos module executes the RAM-based update software. This starts the actual code (flash image) download process. The LCD shows the progress.
- A reset starts the new application on the Chronos module when the update is finished.
The FAQ in Section A also list common questions on the wireless update feature.