Robert Bailey

Developers Bootloader AN2295,  HCS08, Special issues with USB

Discussion created by Robert Bailey on Dec 21, 2006
Latest reply on May 12, 2009 by Robert Bailey
I am having decent results using AN2295 in my product, it has an FT232RL on board as the USB interface. There are several issues related to the USB.

Since I don't have an I/O I can use as a boot trigger (like IRQ), the only entry mode to bootloader is the power on delay. Due to the lagtime associated with the USB port - serial port waking up in the PC, the power on delay doesn't work to signal the PC.

I made a change in the bootloader, I send a trigger message to my application so it can vector into the bootloader. This works ok.

Here's the problem: If reprogramming fails, I have no way for the customer to re-enter programming mode.

What I want to do is change the sequence of programming so that if the entire program is not loaded properly the bootloader will start.

Anyone modded the Master program? I want to write a couple bytes to a known location in the flash once the program is loaded and functional. A checksum would be awesome, but just a status word would work.

Any other (better) solutions?