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Use EzDSP board as emulator?

Hi:

I have recently begun using an EzDSP board from Spectrum Digital for the TMS320F2812. On the board is a FPGA implementing an embedded JTAG emulation port, which talks to the PC via a parallel printer port.

I am thinking it is possible to use this board as a JTAG emulator for a TMS320F2812 chip on *any* board, such as one I design myself. That way, I could have general purpose JTAG emulation (though perhaps restricted to the F2812) for the price of an EzDSP board, instead of the minimum of $1299 that other emulators cost.

What other limitations might this introduce? There appear to be flash programming capabilities in the other emulators, but as I understand the F2812, it needs to program itself via a RAM based routine anyway, and this can be done (albeit in a slightly awkward manner) through CCS using a plugin that TI now makes available on the web for free.

Any comments would be appreciated.

Good day!

-- ____________________________________ Christopher R. Carlen Principal Laser/Optical Technologist Sandia National Laboratories CA USA snipped-for-privacy@sandia.gov

Reply to
Chris Carlen
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To boil this down where I can understand it, are you saying that you want to connect to the EzDSP with the parallel printer port from your DSP, then to your own board from the EzDSP board through JTAG? That sounds like a strange thing to do. I suggest an alternative - watch Ebay for a Spectrum Digital XDS510PP (parallel port version - cheaper than USB). I've seen them for $500, but that was a while ago. You are going to have a headache trying to make the EzDSP board work as an emulator. I think it would not be worth the effort. It is also a good thing to stay current with the TI Code Composer development envirionment. I had several problems with the earlier versions but have been running fine for a year or more on CCS v2.2xx.

SDFlash, from Spectrum Digital, is available in a beta version (could be released already) that will download to the EzDSP through the serial port using the `2812's built-in boot functions. The bootloader is part of the 2812's boot rom. This method is FREE, but of course it really, really strangles development because you'll have trouble seeing inside your code when it runs.

Reply to
David_Haile

Connect to EzDSP via parallel port from PC. Then to my own board not from the JTAG emulator port on the EzDSP, but from the actual connections to the DSP chip on the EzDSP board. I hadn't actually thought of trying to tie the JTAG port of one EzDSP to the JTAG pins of the DSP on another board. I suspect this is the obvious attempt that they would have made impossible. That's because the JTAG interface to the DSP is implemented by the on board FPGA, which also adapts the parallel port interface to the local JTAG.

So I figured I could scrap one EzDSP board for use as a development board, and instead turn it into a JTAG emulator, by pulling off the DSP chip, or just breaking the traces to the JTAG pins, and sending them off to the JTAG pins of the chip on another board.

Yeah, I have 2.2.x also. Good idea to look for a cheaper used parallel port version.

Thanks for the input.

Good day!

--
____________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarle@sandia.gov
Reply to
Chris Carlen

Years ago, I did a similar thing with an eval board from Motorola. It contained a target evaluation system with a 56303 and surrounding peripherals and a 56002 with a serial port as a JTAG interface. The supplied debugger talked to the 56002 which in turn controlled the 56303 using JTAG. The nice thing about this board was that it had the JTAG connection through jumpers, to enable a real JTAG debugger to be attached to the target 56303. But I used it the other way around: pulled the JTAG jumpers and made a cable that could connect my own 56303 system to the 56002 on the eval board. This gave me full unrestricted JTAG debugging, even with the later purchased Tasking 56xxx debugger software.

Meindert

Reply to
Meindert Sprang

Looking the schematics of EzDSP JTAG connector is one way only (from external emulator to EzDSP, more specificly from external emulator to FPGA to DSP). So the only way to use EzDSP is to connect directly to DSP JTAG pins. More sophisticated approach would be if you would disconnect JTAG connector to FPGA trace(lifting selected FPGA pins?), and connect DSP JTAG pins to JTAG connector. This way you would still have EzDSP functionality when DSP was in socket and when you needed emulator you would simply take DSP out (assuming you have EzDSP 2812 socketed version). But this is just theory, if you out this into practice let us know

Mitja

Reply to
Mitja Nemec

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