SLUUB65B May 2015 – December 2022
Some development effort is necessary for a user to implement a program that can open a BQFS and give out I2C or HDQ commands based on the BQFS format. During the development phase, TI recommends that a user have a dedicated prototype board that allows easy replacement of target devices. This is because during the debugging of the program, it is most likely that devices become useless.
The BQFS sequence is created so as to minimize the chances of hindering any devices in the program debug process and also during the actual production run. During debug, once a target device is placed in ROM mode, the program developer must not exit ROM mode unless the full process is completed successfully. Exiting ROM mode while the firmware or data flash is not fully programmed can place the device in an unrecoverable mode.
The BQFS file contains some sequences defined as Read and Compare. When implementing these commands within the user’s program, these commands must be used as checkpoints with which the program developer decides to continue with the process or actually start from the beginning of the BQFS sequence. The user must decide how many attempts to make before considering a device unprogrammable.