Configuration
J1: Target reset configuration
Jumper J1 connects the reset line between the emulation device and the target. By default J1 is
populated.
J2 and J3: Clock source configuration
Jumpers J2 and J3 select external clock source (XOSC) for the emulation device. Per default,
both jumpers are set to position 1-2, which yields the external clock (XOSC) source being used
from the target.
If an oscillator in the target is not an option and the target crystal doesn’t oscillate in
conjunction with the emulation adapter, the emulation adapter can also provide the external
clock (XOSC) source by setting jumpers J2 and J3 in position 2-3. In this case, a crystal circuit
must be built on the emulation adapter.
Note that the Emulation Adapter may not operate when crystal circuit is used in the target.
Typical design guideline is that the crystal should be as close as possible to the
microcontroller.
It can happen that the target crystal does not oscillate in conjunction with the Emulation
Adapter since clock lines (XTAL, EXTAL) between the target crystal and the emulation
device on the Emulation Adapter become too long, inevitably too much affecting the
impedance of the crystal circuit. If a “standalone” oscillator is used instead of the crystal
circuit, no problems are expected.
The crystal packed separately in the antistatic bag comes along the Emulation Adapter. It
can be used to feed an external clock source (XOSC) to the emulation device by inserting
the crystal into the Q1 socket. If a different clock frequency is required, use suitable
crystal and insert it into the Q1 socket.
The emulation adapters of revision A2 or lower were delivered with a 40 MHz crystal,
while the adapters of revision A3 or higher are delivered with a 20 MHz crystal.
Crystal Q1 is located in the corner of the emulation adapter, next to the 38-pin Mictor connector
P1 and per default not populated.
