
207
CHAPTER 13 ASYNCHRONOUS SERIAL INTERFACE
User’s Manual U15017EJ2V0UD
Caution
If a write operation to BRGC0 is performed during communication, the baud rate generator
output will become garbled and normal communication will not be achieved. Therefore, do
not perform write operations to BRGC0 during communication.
Remarks 1.
f
SCK
: Source clock of 5-bit counter
2.
m:
Value set by TPS00 to TPS02 (0
≤
m
≤
6)
3.
k:
Value set by MDL00 to MDL03 (0
≤
k
≤
14)
Table 13-3. Serial Interface Operation Mode Settings
(1) Operation stopped mode
ASIM0
CSIM0
PM25 P25 PM26 P26 PM27 P27
First
Bit
Shift
P25/SI0/RxD0
Clock Pin Function
P26/SO0/TxD0
P27/SCK0/ASCK0
Pin Function
TXE0 RXE0 CSIE0 SCL01 SCL00
Pin Function
0
0
0
×
×
×
Note 1
×
Note 1
×
Note 1
×
Note 1
×
Note 1
×
Note 1
P25
P26
P27
Other than above
Setting prohibited
(2) Asynchronous serial interface mode
ASIM0
CSIM0
PM25 P25 PM26 P26 PM27 P27
First
Bit
Shift
P25/SI0/RxD0
Clock Pin Function
P26/SO0/TxD0
P27/SCK0/ASCK0
Pin Function
TXE0 RXE0 CSIE0 SCL01 SCL00
Pin Function
1
0
0
×
×
×
Note 1
×
Note 1
0
Note 2
0
1
×
LSB
External
P25
TxD0
ASCK0 input
clock
(CMOS output)
×
Note 1
×
Note 1
Interna
l
clock
P27
0
1
1
×
×
Note 1
×
Note 1
1
×
External
clock
RxD
P26
ASCK0 input
×
Note 1
×
Note 1
Interna
l
clock
P27
1
1
0
Note 2
0
1
×
External
clock
TxD0
ASCK0 input
(CMOS output)
×
Note 1
×
Note 1
Interna
l
clock
P27
Other than above
Setting prohibited
Notes 1.
These pins can be used for port functions.
2.
Refer to
13.4.2 Asynchronous serial interface (UART) mode (2) Communication operation (c)
transmission
.