Crystal socket Q1 schematics below:
J4 & J5: GND connection points
In case a good ground connection is required, connection points bridge J4 and pin J5 provide
easy access to the emulation adapter GND potential.
J6 & J7: VFLEX & VAREF
VFLEX
- If the target’s VFLEX pin isn’t exposed, set the jumper to the position J6 to connect
VEXT from the target to power VFLEX.