TASKING iSYSTEM ST SPC58, Руководство пользователя по оборудованию

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Capacitors C85 and C86, for which pads are provided on
the EA PCB, are not populated since the microcontroller
provides already the internal load capacitors for 40MHz
crystal oscillator operation.
J4 and J5: GND connecting points
Real target microcontroller in the 176-pin package provides an exposed GND pad in the middle
of the microcontroller at the bottom side of the package. This provides GND connection between
the microcontroller and the target.
In case of the EA usage, the solder part is soldered instead of the microcontroller. Note that
available solder parts until the introduction of this EA, haven't provided support for the exposed
GND pad.
Ensure a replacement GND connection between the EA and the target using a dedicated GND
wire. Without this connection, the system will not work. Use provided GND wire which comes
along the EA and plug it to the pin J5 (see picture above) on the EA. Connect the other side to
the ground potential on the target - as close as possible to the microcontroller respectively
solder part being soldered instead of the microcontroller. This connection must be quality and
reliable otherwise debugging and tracing over the Nexus trace port may not work. Alternatively,
GND connection can be also established over the J4 ground bridge.