Application with two STM-32 MCU and one STLINK-V2 port (to one of the MCUs) - cascading possible?
An application will use two STM-32 MCUs - for purpose of this posting, I'll call them "outer" (it's SWDIO and SWCLK pins can be attached to a STLINK-V2 device for firmware downloading), and "inner" (it's SWDIO and SWCLK pins would be tied to two GPIO pins of "outer", and not be externally accessible.)
My question is this - is it possible (by a combination of firmware running on "outer" and appropriate settings to STLINK-V2 such as an acceptable clock frequency) to have the "outer" MCU provide a transparent path (using as-yet undefined firmware running on "outer") so that STLINK-V2 attached to outer's SWDIO/SWCLK pins is passed bit-for-bit to the two GPIO pins (on "outer") which would be connected to SWDIO/SWCLK of "inner" MCU?
The intent of this is to avoid having two separate connectors to which STLINK-V2 would be attached for debug and firmware delivery, and not be reliant on a bootloader (that is, the "inner" processor could be reloaded from scratch using STLINK-V2.)
Happy to answer any request for clarification and be guided in different direction if need be.
Thanks