ToolStick-F540DC
Rev. 0.2 7
6. Using the C8051F540 Daughter Card as a Development Platform
The prototyping area on the ToolStick ToolStick-C8051F540DC Daughter Card makes it easy to interface to
external hardware. All of the digital I/O pins are available so it is possible to create a complete system.
6.1. C8051F540 Pin Connections
It is important to note that if external hardware is being added, some of the existing components on the board can
interfere with the signaling. The following is a list of port pins on the ToolStick-C8051F540DC that are connected to
other components:
P0.0—This pin is connected to a 1.0 uF capacitor, which serves as a decoupling capacitor for the on-chip
voltage reference. The capacitor C3 can be removed to disconnect it from the pin.
P0.4, P0.5—These pins are connected directly to the ToolStick Base Adapter for UART communication.
P1.0, P1.1—These pins are connected to the TXD and RXD pins of the LIN transceiver. The LIN transceiver
can be removed to disconnect it from the pins.
P1.2—This pin is connected to the anode of the green LED on the daughter card. The LED or the R2 resistor
can be removed to disconnect the LED from the pin.
P1.3—This pin is connected to the output of the potentiometer. The 0 ohm resistor R5 can be removed to
disconnect the potentiometer from the pin.
P1.4—This pin is connected to the P1.4 switch. The switch can be removed to disconnect it from the pin.
P1.5, P1.6—These pins are connected directly to the ToolStick Base Adapter’s GPIO pins. By default, these
GPIO pins on the Base Adapter are high-impedance pins so they will not affect any signaling. Configuring these
pins on the Base Adapter to output pins or handshaking pins could affect signaling.
See the daughter card schematic in Section 7 for more information.
6.2. Local Interconnect Network (LIN) Transceiver
The ToolStick-C8051F540DC daughter card includes a LIN transceiver to enable communication on LIN networks.
The LIN transceiver requires a higher voltage than the 5 V provided by the USB interface and so a voltage
converter is provided to double the 5 V USB voltage to 10 V. The LIN transceiver can also be powered through the
TB1 external header. If both voltage sources are present, the higher voltage is automatically selected for the
transceiver.
6.3. C2 Pin Sharing
On the ToolStick-C8051F540DC, the debug pins, C2CK, and C2D, are shared with the pins RST and P3.0
respectively. The daughter card includes the resistors necessary to enable pin sharing, which allow the RST
and
P3.0 pins to be used normally while simultaneously debugging the device. See Application Note “AN124: Pin
Sharing Techniques for the C2 Interface” at www.silabs.com for more information regarding pin sharing.
