Breakout board for JTAG access

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Breakout board for JTAG access

Postby ticso » Tue Apr 29, 2014 11:32 pm

It seems the supplied u-boot inside the QSPI flash can't directly be used to boot FreeBSD.
That's what Thomas Skibo told me, who is working on Zedboard for FreeBSD.
Unfortunately it seems he has to wait much longer for his Parallella since he is on a preorder list for a 7010.
Adapteva, if you can do something to speed up his order it would be very helpfull, since he is a key developer for porting FreeBSD to Parallella.
Back to the main subject:
Modifying that u-boot risks bricking the board unless you have a save to flash binary, which we don't have yet.
I do have a Xilinx compatible JTAG, but need a breakout board to at least something more practical than the Samtec.
Is there any kind of breakout board available for order?
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Re: Breakout board for JTAG access

Postby patc » Wed Aug 06, 2014 8:44 pm

Got my Parallella yesterday evening. Bummer, those Samtec connectors aren't easy to find... eventually placed an order on Toby Electronics in UK. Delivery in 6 weeks but I feel tense and can't sleep well until I've hooked the JTAG probe to communicate with the FPGA and Cortex-A9.

First tried to solder directly on the PEC_power connector: very bad idea, don't do it because contacts extend below the connector and to remove shorts is almost impossible. Next looking at the schematics, luckily there are resistors on each 4 JTAG lines, R9/10/11/12, and that's much easier.

Defintely NOT recommended but without the proper connector at hand, this works.

Do at your own risks and use EXTREME caution else the board might very well end up in the trash can!
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Last edited by patc on Fri Aug 08, 2014 4:31 pm, edited 1 time in total.
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Re: Breakout board for JTAG access

Postby patc » Thu Aug 07, 2014 2:03 pm

Following yesterday rant and based on Adapteva's parallella-hw-master\fpga\edk\parallella_7020_headless\data\ps7_system_prj.xml, below is the DDR3 setting under Vivad0 2014.2

Zynq DRAM Diagnostics test: Memory Test passed (tested on 7020 but should be the same for 7010).
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Re: Breakout board for JTAG access

Postby patc » Fri Aug 08, 2014 4:28 pm

To complete this part, a small extension has been added with:
- JTAG connector
- reset button
- QSPI/JTAG boot dip switch
- FPGA Done led

The heatsink is maintained by 2 isolated bolts and nuts in TP13/TP14 with some thermal grease applied on the chips.
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