Silicon Laboratories C8051F30 Series User Manual page 9

4.5. Serial Interface (J5)
A RS232 transceiver circuit and DB-9 (J5) connector are provided on the target board to facilitate serial connec-
tions to UART0 of the C8051F300. The TX, RX, RTS and CTS signals of UART0 may be connected to the DB-9
connector and transceiver by installing shorting blocks on headers J3.
J3[5–6]- Install shorting block to connect UART0 TX (P0.4) to transceiver.
J3[7–8]- Install shorting block to connect UART0 RX (P0.5) to transceiver.
J3[9–10]- Install shorting block to connect UART0 RTS (P0.2) to transceiver.
J3[11–12]- Install shorting block to connect UART0 CTS (P0.3) to transceiver.
4.6. Analog I/O (J6)
Several of the C8051F300 target device's port pins are connected to the J6 terminal block. Refer to Table 4 for the
J6 terminal block connections. Install a shorting block on J7[2-3] to connect the AIN6 input to the P0.6 pin of the
target device.
4.7. Low-Pass Filter (J7)
The C8051F300 target board features a low-pass filter that may be connected to port pin P0.6. Install a shorting
block on J7[1-2] to connect the P0.6 pin of the target device to the low-pass filter input. The output of the low-pass
filter is routed to the PWM signal at J1[2]. The C8051F300 may be programmed to generate a PWM (Pulse-Width
Modulated) waveform which is then input to the low-pass filter to implement a user-controlled PWM digital-to-ana-
log converter. Refer to Applications Note "AN107: Implementing 16-Bit PWM Using the PCA" in the "documenta-
tion" directory on the CD-ROM for a discussion on generating a programmable dc voltage level with a PWM
waveform and low-pass filter.
Table 4. J6 Terminal Block Pin Descriptions
Pin # Description
1 P0.1 / AIN1 (ADC input 1)
2 AIN6 (ADC input 6)
3 GND (Ground)
4 P0.0 / Vref (Voltage Reference)
Rev. 0.6
C8051F30x
9