sensor_core JTAG interface

I am trying to read back the IDCODES of all TAP controllers, currently it seems I am only able to read back the toplevel TAP controller and QUARK TAP controller, but the ARCSS/sensor_core TAP controller seems not visible.

When reading:

document the ARC SS/ sensor_core should be visible? Also the read back IDCODES of Toplevel tap and quark TAP are correct, see page 16 and 17

Reading IDCODES: - CLTAPC 0x2 --> 0x0e765013 - QUARK 0x2 --> 0x38289013 - ARCSS --> 0x0

Looking forward to ideas from the field on how to resolve this?

Thanks already

Are you placing the ARC target in the tap chain? As noted in page 12 of the debug operations doc, you must set the appropriate bits in ARC_TAP_SEL of CLTAPC_SELECT in order to add the ARC to the chain.

Take a look at the openocd scripts/target/quark_x10xx.cfg as an example of how this is done for a single-core device with a CLTAP. This can be extended to add the ARC as a tap target which can be enabled.