Re: [OpenOCD-user] FT2232 device

[Tomas V. <to...@us...>]

On 02.08.2016 19:13, Trampas Stern wrote:
> The resistor hack is basically a hack, but would be better if a 
> Schottky diode was used with a pull up resistor. This would simulate 
> the TDI being an open collector driver and only pulling down the 
> SWDIO.  Also for some hardware the debugger should have a pull up on 
> the SWDIO.
Certainly not. Pull up on SWDIO is really weak, just to prevent line 
floating. Asymmetric drive of open collector with the capacity of a 
cable would have much steeper failing slope than rising - this would 
limit reachable frequency.

If you don't want to use a hack, you should connect a 3-state driver 
from TDI output to SWDIO and configure a FT2232 pin as a signal to 
enable it.
See kt-link.cfg.

Tomas