OK... Could somebody tell me which pins on external MCU do I need to connect to J103 then (as I think there's a consensus that J103 can be used to program ext. MCU)...?
How about J103 - XDSET_DEBUG_CON... The description on the schematic: "External XDS-ET access. Debug external targets. Set S101 appropriately".
Could this be used (somehow) to program external MCU?
Or - perhaps Hercules RM42 (as I have one in my drawer)? There's unpopulated jtag header btu I'm not sure if it can be used to program external targets...