C80 51 F 53 x/5 2x
Rev. 0.4
9
5.6. USB to Serial Connector (P1, HDR4)
A USB-to-Serial bridge interface is provided. A B-type USB connector (P1), a CP2102, and related circuits are
provided to facilitate the serial connection between a PC and the U2 A-Side C8051F530A microcontroller on the
target board. The RX, TX, CTS, and RTS signals of the UART side of the Bridge (CP2102) may be connected to
the microcontroller by installing shorting blocks on HDR4 as shown in Table 5.
The BUS-Powered CP2102 uses the 5 V provided by the USB interface.
5.7. Analog I/O (TB2, J3, J4, J5)
The Analog connector block (TB2) and headers J3, J4, and J5 provide Analog inputs to the C8051F530A (U2) as
shown in Table 6. Headers J3, J4, and J5 connect the inputs from the Analog connector to the microcontroller pins.
5.8. Power Supply Options (P5, TB1, J13, J14)
The target board provides two options of power supply. The first option is to use the provided 9 V power supply
attached to the P5 connector. The second option is to use an external 12 V (7.5 V minimum) connected to the TB1
terminal block (pins 1 and 3).
Headers J13 and J14 connect the +5 V power supply to the VREGIN pins on U1 and U2. These headers can be
populated to supply power directly or depopulated to measure the operating current drawn by the corresponding
C8051F530A device.
Table 5. UART Connections
HDR3
Connection
Signals
5–6
P0.4_A to TX_A
7–8
P0.5_A to RX_A
9–10
P1.1_A to RTS_A
11–12
P1.2_A to CTS_A
Table 6. Analog I/O Connections
TB2
Signal
Connection
I/O
Shorting Block
Vrefin
External Reference Input or Internal Reference Output
P0.0_A
J5
CH1
Analog Input 1
P1.6_A_MC
J3
CH2
Analog Input 1
P1.7_A_MC
J4
GND
Ground
GND
—
