Posted on May 17, 2011 at 11:51Hi All,
I have a question regarding the GPLD of the uPSD3354. My device (a Bluetooth printer) has a bootloader (capable of IAP) and a main application. The main application requires the use of the PSD GPLD to capture some signals during printing where as the bootloader makes no use of the GPLD. I have two PSDSoft Express projects - one for the bootloader and one for the application. The application PSDSoft project sets-up an Input Macro Cell (IMC) of the GPLD to capture some signals during printing.
Now, as you all know, the PLD can ONLY be programmed via JTAG - not via program code in the micro. So when I JTAG my bootloader onto the board I get a particular configuration of the PLD - that which was in the bootloader project. I then use the bootloader IAP feature to load may application. I have since realised that this means that the GPLD settings I need for the main app to function will NOT get programmed into the PLD as I am not using JTAG.
So, I was very suprised to see that the printer worked OK (for the most part) and the GPLD IMC was capturing the signals. I would have thought that the GPLD would have been programmed with the settings of bootloader project. Now, I say above 'for the most part' and this is why this issue first arose. When the power to the printer was switched on->off->on quickly, the product would startup, the micro would report a COLD RESET yet when the printer application was started, we had no comms to the printer. Inspection of the signalling showed that all signals were OK, but they were just not being captured by the PLD, i.e. the PLD configuration was wrong.
I have since made the PSDSoft Express configuration common to both projects (bootloader and application) and all appears to be OK now, but I am struggling to understand how the printer app ever worked when it was programmed via IAP. Also I need to understand why the rapid cycling of power triggered this problem whereas a slower on->off->on cycle meant all was well. The HW engineers here tell me that the HW is fine and I am lnclined to agree with them - it looks more like something is not quite right with the PLD settings.
Any experts out there wanna help me out with this one?
Cheers
Andy
