>Hello. I have some conceptual questions on emulator and HPI. What is >the benefit of using an external emulator instead of an embedded JTAG >to perform debugging of a DSP board (with CCS)? I understand from a >good friend who has always answered my questions that with an >external emulator I would save cost if many boards were built (save >on not needing an embedded JTAG on the board). If by embedded JTAG you mean the same approach as the DSK then your friend is correct. Basically, the 'embedded JTAG' circuitry is placed on a board inside your PC, or between the parallel port and the board under test. You unit then has the 14 pin header and nothing else on it. Therefore you have exactly the same capabilities as before, just the interface chips have moved. > Suppose that is true, >and I believe it is since it is from a reliable source, do I have to >download the application program onto the FLASH ROM first before I >can use an external emulator? You should be able to use either mode of emulation to load your flash, because both allow you to load code and data into the processor anyway. >The reason I ask this is because the >external emulator needs to be connected onto the parallel port but so >does the DSK itself. I read that with an external emulator the DSK >itself need not be connected to the parallel (i.e. only the external >emulator needs to be connected). Is that true? If that is true and if >I don't have to download the application program to FLASH ROM, that >would mean that the application program is somehow transferred to the >DSP via the external emulator. Is this true? Both styles of emulator can load code into the processor/memory > The reason why I ask >this is because I am trying to design my own board and am wondering, >if I should decide to use the external emulator, if I need to have >aIEEE1284 port on my board (I definitely need the 14pin Emulator port >since I am using an external emulator). Now suppose that I don't need >a IEEE1284 port on the DSP board can I flash the application program >down onto the FLASH ROM via the emulator? Yes, you don't need an IEEE1284 port. >This seems impossible >because I could not see how the signals from the emulator could be >connected to the DSP for the downloading to occur. From the 14 pin header. > This brings me to >my next question. If I run a program from CCS, how is the application >program relay to the DSP? Does the PC send one instruction at a time >to the DSP or is the application program downloaded all at once onto >the DSP (to its internal RAM for example)? > CCS downloads the code/dta into the DSPs internal memory and external storage and then tells it to run. Or single step. Or set a breakpoint. Or whatever. But fundamentally everything to do with execution takes places inside the DSP and its assocaited memory. >All responses/advises/comments are welcome. Hope it helps! Cheers, Martin -- Martin Thompson BEng(Hons) CEng MIEE TRW Automotive Advanced Product Development, Stratford Road, Solihull, B90 4GW. UK Tel: +44 (0)121-627-3569 mailto: |