Cirrus Logic CDB5378 - Manual (Page 36)

CDB5378
36 DS639DB4
2.5.4 Dual-row Headers
To simplify signal tracing on CDB5378, all device pins connect to dual-row headers. These dual-row head-
ers are not populated during board manufacture, but the empty PCB footprint exists on the boards and
can be used as test points.
The dual-row header pins are shorted on the bottom side of the PCB to pass signals through to the rest
of the board. These shorted traces between the dual-row pins can be carefully cut to isolate the device
signals from the rest of the PCB to permit wiring changes to the existing route. To restore the previous
connection, install a jumper to short across the dual-row pins.
Signals taken off the PCB should not be wired directly from the dual-row header pins, as there is no clean
path for the signal return current. Instead, install a connector into the prototying area and wire the signal
and a ground connection to it. Pairing the signal with a ground return before taking it off the PCB will im-
prove signal integrity.
Figure 7. Dual-row Headers with Shorts