C8051F800-DK
Rev. 0.2
11
7.5. Target Board Debug Interface (J4)
The DEBUG connector J4 provides access to the DEBUG (C2) pins of the C8051F800. It is used to connect the
Serial Adapter or the USB Debug Adapter to the target board for in-circuit debugging and Flash programming.
Table 2 shows the DEBUG pin definitions.
7.6. Serial Interface (P2, J3)
A USB-to-UART bridge circuit (U3) and USB connector (P2) are provided on the target board to facilitate serial
connections to UART0 of the C8051F800. The Silicon Labs CP2103 USB-to-UART bridge provides data
connectivity between the C8051F800 and the PC via a USB port. The TX, RX, RTS and CTS signals of UART0
may be connected to the CP2103 by installing shorting blocks on header J3. Note that the use of the optional RTS/
CTS handshaking signals will prevent the simultaneous use of the capacitive sense switches because those GPIO
pins are shared on this board. The shorting block positions for connecting each of these signals to the CP2103 are
listed in Table 3. To use this interface, the USB-to-UART device drivers should be installed as described in Section
4.3. "CP210x USB to UART VCP Driver Installation‚" on page 3.
7.7. Potentiometer (J6, J7)
The C8051F800 MCU has the option to connect port pin P0.7 to a 10K linear potentiometer (R14). The
potentiometer is connected through the J6 and J7 headers. The potentiometer can be used for testing the analog-
to-digital (ADC) converter of the MCU.
Table 2. DEBUG Connector Pin Descriptions
Pin #
Description
1
+3 VD (+3.3 VDC)
2, 3, 9
GND (Ground)
4
P2.0/C2D
5
RST (Reset)
6
P2.0
7
RST/C2CK
8
Not Connected
10
USB Power (+5 VDC)
Table 3. Serial Interface Header Description
Header Pins UART0 Pin Description
J3[11–12]
TX_MCU (P0.4)
J3[13–14]
RX_MCU (P0.5)
J3[15–16]
RTS (P1.5)
J3[17–18]
CTS (P1.6)
