Program JTAG-DP on STM32F102xx

[aman.32]

We want to use the STM32F10x MCU as a JTAG dongle. Can we make use of the TDO, TDI and TMS on the chip or they are use solely for M3 debugging? Thanks.

[Uwe Bonnes]

Yes, you can use JTAG to access the output pin.

[aman.32]

I understand JTAG pin can be assigned to GPIO pin. My question is to use TDO, TDI, TMS pin to drive other device which accept JTAG command.

For example, I want to test boundary scan of a device. I connect all the pins as required. Can we program ST MCU to drive this device in JTAG mode? There is no example how I can do so. Thank.

[Uwe Bonnes]

No, STM Jtag/SWO is only a slave. STM32 is no JTAG/SWD master per se. But you can program pins to work as SWD/JTAG master with software, like in the STlink or the Bl*ack M*g*c Debug probe.