32176 Group
Starter Kit User’s Manual M3A-2152
REJ10B0224-0300/Rev.3.00 Jan. 2007 Page 49 of 82
2.4 Serial I/O Interface
The evaluation board is interfaced to the host PC (DOS/V) through its RS-232C by using SIO of the
M32R/ECU.
Of the RS-232C control signals, only TXD and RXD are used for connection to the host PC (DOS/V).
The unused CTS and RTS are directly-coupled to configure a loop-back. The unused DSR and DTR
also are configured in a similar manner. The serial I/O interface is configured in such a way that
only one serial I/O channel can be used at a time.
Any of the four channels 0–3 can be selected using a rotary switch.
Figure 2.4 Serial I/O Interface