tmp89fm42a TOSHIBA Semiconductor CORPORATION, tmp89fm42a Datasheet - Page 149

• Manufacturer Part Number: tmp89fm42a
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

8.4
Serial Interface Selecting Function
RA006
Serial interface selection control register
UART input/output change control register
(0x0FCB)
UATCNG
(0x0F57)
SERSEL
Note 1: The operation for changing SERSEL must be executed while the applicable serial interface and timer counter operations
Note 2: It is recommended to clear the interrupt latch for the applicable serial interface immediately after changing SERSEL.
Note 1: The operation for changing UATCNG must be executed while the applicable serial interface operations are stopped.
TCA0SEL
UAT1IO
UAT0IO
SRSEL2
SRSEL0
Read/Write
Read/Write
Bit Symbol
Bit Symbol
After reset
are stopped. If SERSEL is switched during operation of these peripheral functions, each peripheral function may receive
(transmit) unexpected data and operate improperly.
Interrupt latches are common to INTRXD and INTSIO and to INTSBI and INTSIO. Therefore, if an interrupt occurs before
or after SERSEL is switched, it is difficult to tell which function has caused the interrupt.
After reset
Select UART1 input/ output port
Select UART0 input/ output port
16-bit timer counter A0 input switch-
ing
Select UART0/SIO0 input/output
port
Serial interface selection 0
R/W
R
7
0
7
0
-
TCA0SEL
R/W
R
6
0
6
0
-
0:
1:
0:
1:
R
R
5
0
5
0
Page 130
-
00:
01:
10:
11:
00:
01:
10:
11:
P91
P90
P21
P20
0:
1:
<SERSEL2>="0"
SERSEL
P72 input (TCA0)
P21 input (also used as RXD0)
P91 input (also used as RXD1)
Reserved
Select P20, P21, P22
Select PB4, PB5, PB6
Select UART0, I2C0
Select UART0, SIO0
Select SIO0, I2C0
Reserved
SRSEL2
R/W
R
4
0
4
0
-
RXD pin
PB5
PB4
<SERSEL2>="1"
SERSEL
R
R
3
0
3
0
-
P90
P91
P20
P21
<SERSEL2>="0"
R
R
0
0
2
2
-
SERSEL
UAT1IO
R/W
R/W
TXD pin
1
0
1
0
TMP89FM42A
SRSEL0
PB4
PB5
<SERSEL2>="1"
SERSEL
UAT0IO
R/W
R/W
0
0
0
0