Apologies if this is a naive question, I’m more of a software person.
Are JTAG cables and ports generally compatible (assuming most of the same pins), or do certain ports require certain cables? I have a NAS box using a Marvell ARM SoC with known JTAG pins (10 pins, sRST, TDO, TCK x2, TMS, TDI, nTRST, GND x2, Vcc) and a parallel JTAG cable (6 pins, TDO, TCK, TMS, TDI, GND, Vcc; 2.8V up to 5V) from the old Xilinx Spartan 3E starter kit.
Will this cable work if I wire it up to the pins on the NAS? If not, what sort of cable do I need?
Any help or education on this sort of thing would be appreciated.
The Xilinx software only supports the Xilinx cable and Xilinx devices. Similarly, an ARM JTAG is only supported by ARM tools for ARM devices. Amontec makes JTAG interfaces with a CPLD that is reprogrammed for different tools and target devices, with different hardware interfaces for the different types of JTAG connectors.
10 pins is rather unusual for an ARM JTAG connector, the ARM standard is a 20 pin connector.
I wasn’t planning on using the Xilinx software, just the cable, so I wanted to know if it was compatible (electrically). Would wiring the signals present on the cable to the port on the NAS board work with OpenOCD for example? From what I understand people have done it with home-made ‘wiggler’ style cables, but I’m not exactly sure what qualifies as a wiggler…
The Amontec cable looks neat, but it’s a little pricey for the amount of use I’d get out of it.
If you wrote your own software you could probbaly make it compatible with some hardware mods (the connections are different), but it’s a waste of time.
