Datasheet

M16C/6S Group UART Mode
R01DS0201EJ0502 Rev.5.02 page 111 of 203
Dec 25, 2012
Table 1.15.3 lists the functions of the input/output pins during UART mode. Table 1.15.4 lists the P64 pin
functions during UART mode. Note that for a period from when the UARTi operation mode is selected to
when transfer starts, the TxDi pin outputs an “H”. (If the N-channel open-drain output is selected, this pin
is in a high-impedance state.)
Table 1.15.3. I/O Pin Functions
Pin name Function Method of selection
TxDi (i = 0 to 2)
(P6
3 , P6 7 , P7 0 )
Serial data output
Serial data input
Input/output port
Transfer clock input
Input/output port
(Outputs dummy data when performing reception only)
RxDi
(P6
2 , P6 6 , P7 1 )
CLKi
(P6
1 , P6 5 )
UiMR register’s CKDIR bit=0
UiMR register’s CKDIR bit=1
PD6 register’s PD6_1 bit=0, PD6_5 bit=0, PD7 register’s PD7_2 bit=0
PD6 register’s PD6_2 bit=0, PD6_6 bit=0, PD7 register’s PD7_1 bit=0
(Can be used as an input port when performing transmission only)
UiC0 register’s CRD bit=0
UiC0 register’s CRS bit=0
PD6 register’s PD6_0 bit=0, PD6_4 bit=0, PD7 register’s PD7_3 bit=0
UiC0 register’s CRD bit=0
UiC0 register’s CRS bit=1
UiC0 register’s CRD bit=1
CTS input
RTS output
CTSi/RTSi
(P6
0 , P6 4 , P7 3 )
Table 1.15.4. P64 Pin Functions
Pin function Bit set value
U1C0 register
UCON register PD6 register
CRD
CRS
RCSP
CLKMD1
PD6_4
P64
1 00Input: 0, Output: 1
CTS
1 0000
RTS
1 10 0
CTS
0 (Note) 0
0
0
00 1 0
Note: In addition to this, set the U0C0 register’s CRD bit to “0” (CTS0/RTS0
enabled) and the U0C0 register’s CRS bit to “1” (RTS
0 selected).