AN172
Rev. 0.4
7
6.4. 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 C8051F020. The TX, RX, RTS and CTS signals of UART0 may be connected to the DB-9
connector and transceiver by installing shorting blocks on jumpers J6, J8, J9 and J10.
J6
- Install shorting block to connect UART0 TX (P0.0) to transceiver.
J9
- Install shorting block to connect UART0 RX (P0.1) to transceiver.
J8
- Install shorting block to connect UART0 RTS (P4.0) to transceiver.
J10 - Install shorting block to connect UART0 CTS (P4.1) to transceiver.
6.5. Analog I/O (J11, J20)
Several C8051F020 analog signals are routed to the J20 terminal block and the J11 jumper block. Jumper block
J11 provides the ability to connect DAC0 and DAC1 outputs to several different analog inputs by installing a short-
ing block between a DAC output and an analog input on adjacent pins of J11. Refer to Table 3 for J20 terminal
block connections and Table 4 for J11 pin definitions.
Pin #
Description
1
CP0+
2
CP0-
3
DAC0
4
DAC1
5
AIN0.0
6
AIN0.1
7
VREF0
8
ADND (Analog Ground)
Table 3. J20 Terminal Block Pin Descriptions
Pin #
Description
1
CP0+
2
CP0-
3
DAC0
4
DAC1
5
CP1+
6
CP1-
7
AIN0.0
8
AIN0.1
9
DAC0
10
DAC1
11
AIN0.6
12
AIN0.7
Table 4. J11 Jumper Block Pin Descriptions
