Usb Serial Port - Renesas RX Series User Manual

RSKRX231
5.8

USB Serial Port

A USB serial port is implemented in a Renesas low power microcontroller (RL78/G1C) and is connected to the
RX231 Serial Communications Interface (SCI) module. Multiple options are provided to allow the selection of
the connected SCI5 port. Connections between the USB to Serial converter and the microcontroller are listed
in Table 5-6 below.
Signal Name
1
TXD1 *
1
RXD1 *
TXD5
RXD5
1
TXD12 *
1
RXD12 *
1
RS232TX *
1
RS232RX *
RL78G1CCTS
RL78G1CRTS
1
* : This connection is a not available in the default RSK configuration - refer to §6 for the required
modifications.
When the RSK board is first connected to a PC running Windows™ with the USB/Serial connection, the PC
will look for a driver. This driver is installed during the installation process, so the PC should be able to find it.
The PC will report that it is installing for a driver and then report that a driver has been installed successfully,
as shown in Figure 5-3. The exact messages may vary depending upon operating system.
Rev.
R20UT3027EG0100 1.00
Aug 24, 2015
SCI1 Transmit Signal
SCI1 Receive Signal
SCI5 Transmit Signal
SCI5 Receive Signal
SCI12 Transmit Signal
SCI12 Receive Signal
External SCI Transmit Signal
External SCI Receive Signal
Clear To Send
Request to Send
Table 5-6: Serial Port Connections
Figure 5-3: USB-Serial Windows™ Installation message
Function
5. User Circuitry
MCU
Port Pin
P26 22
P30 20
PA4 66
PA3 67
PE1 77
PE2 76
- -
- -
P15 31
PC0 52
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