tmp89fm42a TOSHIBA Semiconductor CORPORATION, tmp89fm42a Datasheet - Page 247

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

16.4
Protection to Prevent UART0CR1 and UART0CR2 Registers from Being Changed
RA001
16.4
settings (for example, stop bit and parity) are not changed accidentally during the UART operation.
write instruction is executed on the register when it is protected from being changed, the bits remain unchanged and
keep their previous values.
Changed
Table 16-3 Changing of UART0CR1 and UART0CR2
The TMP89FM42A has a function that protects the registers from being changed so that the UART communication
Specific bits of UART0CR1 and UART0CR2 can be changed only under the conditions shown in Table 16-3. If a
Protection to Prevent UART0CR1 and UART0CR2 Registers from Being
UART0CR1<IRDASEL>
UART0CR2<STOPBR>
UART0CR1<STOPBT>
UART0CR2<RXDNC>
UART0CR2<RTSEL>
UART0CR1<EVEN>
UART0CR1<BRG>
Bit to be changed
UART0CR1<PE>
Transfer base clock selection
Selection of number of RT
Selection of RXD pin input
TXD pin output selection
Transmit stop bit length
Receive stop bit length
noise rejection time
Parity selection
Parity addition
Function
clocks
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UART0CR1
<TXE>
Both of these bits are "0"
Both of these bits are "0"
-
Conditions that allow the bit to be changed
UART0SR
<TBSY>
All of these bits are "0"
All of these bits are "0"
-
UART0CR1
<RXE>
Both of these bits are "0"
-
-
UART0SR
TMP89FM42A
<RBSY>
-
-