R8C/3MK Group
USB-to-Serial Communication Conversion Demo Board
R0K5R8C3MDU30BR Instruction Manual
R01AN1051EJ0100 Rev.1.00
Page 17 of 38
Mar 21, 2012
RXD
PC with
RS232C Serial
Port
Control Transfer
Class Request
USB
USB
USB
Communication
USB CDC
Host
RS232C
Communication
RS2
32C
Seriial
PORT
The serial port parameters on the
terminal software reflect UART0.
UART
Device with
UART serial
port
TXD
RS232C
Transceiver
RS23
2C
This Product
UART
0
UART
This product does not use control
signals of CTS/RTS/DSR/DTR etc.
Figure 12 Example of setting the serial port parameters on the terminal software
8.2
USB Downloader Function
When the demo board is turned on while the USB downloader function switch pin (TP1) is grounded (GND),
the USB downloader program is started up. In this function, the user can write a Motorola S Format (mot) file
to the MCU internal flash ROM. The following outlines the sequence until the internal program has been
updated. For more details, refer to the application note titled “R8C/USB Group USB Downloader.”
1) Connection to USB Host (PC)
Connect this demo board to the USB Host (PC) using the USB cable (A-miniB).
(System definition file (CDC_Demo.inf) is required for the initial connection.)
(2) Confirm the COM number (Windows: device manager)
