We have implemented a serial wire debug port (2-pin SWD) in our ASIC, but do not provide access to the DAP via a standard JTAG interface. We have a test setup expects to connect via a classic JTAG interface. Is there a solution that would convert the 4-pin JTAG interface to the serial wire protocol external to the ASIC?
David
Hi David,
I am not aware of any such conversion I am afraid, so you would have to be a bit creative on this front I am afraid.
Most debug tools will handle the protocol directly within the debug hardware that is connected to the JTAG/SWD port.
You could create something that maps JTAG accesses (to a DAP) to SWD accesses, but there's engineering and validation in that.
Or change your test setup to use SWD, but again, there's engineering & validation effort required.
The JTAG-AP port of an ARM DAP doesn't support SWD, so you couldn't somehow synthesize something using that either....
Hope that helps (probably not I suspect).
Regards,
Stuart
Thanks Stuart.
We are looking into using this:
https://www.olimex.com/Products/ARM/JTAG/ARM-USB-TINY/
along with
https://www.olimex.com/Products/ARM/JTAG/ARM-JTAG-SWD/
and hope it would work.
Hi,
Those devices look very interesting, especially the ARM-JTAG-SWD device.
I would be very interested to hear how you get on with these devices if you decide to go ahead and use them.
Thanks,