Wiki > Main > GigabeatFJTAG (compare)
Difference: GigabeatFJTAG (r11 vs. r10)
The Gigabeat F has a JTAG port available on the front of the PCB under the LCD. This port has 10 pins total. Christophe Nicolas has traced the pins and created a pinout of the port. I have included this pinout below layed out as if you were looking at the front of the PCB. Pin 1 is on the right side and is denoted by a white arrow on the board.
To communicate to the JTAG port I used a Xilinx Parallel III cable. Digilent sells a cable that should be compatible with the Xilinx Parallel III on their website for $12 USD (The JTAG3).
The main connections needed to communicate to the Gigabeat with the Parallel III are the TDI, TMS, TDO, TCK, Vcc, and GND. Pin 2 and 5 connect to the Nreset and NTRST pins indirectly through what we think is a TC7W08?. The pinout for this is as follows (Pin 1 and 5 are connected to each other):
The NTRST and Nreset pins can be used by OpenOCD with a cable that supports them, the Parallel III does not have pins to drive them so they were unused with this cable.
The first connection I made to the Gigabeat used solid copper wire from an Ethernet cable. This ended pulling out my ground contact due to the stress on the board when moved. I also could not fully assemble the Gigabeat with the setup.
A flat ribbon cable is recommended to make your connections. On my second connector I used a floppy disk drive cable and cut a piece about 10cm long, 10 wires wide. The ribbon cable spacing almost matches the spacing on the PCB making soldering easier. I connected all 10 pins on the second connector (the first only had TDI, TMS, TDO, TCK, Vcc, and GND).
The floppy connector is stranded wire and my connections to the programming cable are flying leads (note: need to include pictures). To connect to the flying leads I used the solid Ethernet wire, cut pieces 1 cm in length and soldered those to the stranded wire on one end of the ribbon cable.
Soldering to the PCB is not difficult as long as you make sure that you have enough solder on the ribbon wire before you attempt to bond it to the board. Only 2, or, at the most 3 mm of stranded wire should be exposed for soldering to the PCB. This will reduce the chance that wires end up crossed after soldering.
Taking the solder wire near the PCB is not recommended. Instead give each wire on the ribbon cable a thin coat of solder. It should be enough so that when you touch the wire on the board with the iron it reflows onto the board pad (meaning only a thin coat, no globs).
Here is a link to a preliminary version of the Gigabeat Flashwriter. This should not be used unless you have a JTAG interface connected to your player. More work needs to be done to the gigabeat bootloader to make sure that the device is properly initialized.
r13 - 13 May 2010 - 04:53:33 - KarlKurbjunRevision r11 - 13 Mar 2008 - 22:30 - JasonStahls
Revision r10 - 13 Mar 2008 - 02:53 - JasonStahls
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