tmp89fm42a TOSHIBA Semiconductor CORPORATION, tmp89fm42a Datasheet - Page 257

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

16.11
Transmit/Receive Operation
RA001
16.11
16.11.1
16.11.2
data buffer). Writing data into TD0BUF sets UART0SR<TBFL> to "1", transfers the data to the transmit shift
register, and outputs the data sequentially from the TXD0 pin. The data output includes a start bit, stop bits whose
number is specified in UART0CR1<STBT> and a parity bit if parity addition is specified. Select the data transfer
baud rate using UART0CR1<BRG>, UART0CR2<RTSEL> and UART0DR. When data transmission starts, the
transmit buffer full flag UART0SR<TBFL> is cleared to "0" and an INTTXD0 interrupt request is generated.
RD0BUF (receive data buffer). At this time, the transmitted data includes a start bit, stop bit(s) and a parity bit
if parity addition is specified. When the stop bit(s) are received, data only is extracted and transferred to RD0BUF
(receive data buffer). Then the receive buffer full flag UART0SR<RBFL> is set and an INTRXD0 interrupt
request is generated. Set the data transfer baud rate using UART0CR1<BRG>, UART0CR2<RTSEL> and
UART0DR.
but discarded; data in the RD0BUF is not affected.
Transmit/Receive Operation
Note 1: After data is written into TD0BUF, if new data is written into TD0BUF before the previous data is transferred
Note 2: Under the conditions shown in Table 16-9, the TXD0 pin output is fixed at the L or H level according to the
Set UART0CR1<TXE> to "1". Check UART0SR<TBFL> = "0", and then write data into TD0BUF (transmit
Set UART0CR1<RXE> to "1". When data is received via the RXD0 pin, the received data is transferred to
If an overrun error occurs when data is received, the data is not transferred to RD0BUF (receive data buffer)
Data transmit operation
Data receive operation
to the shift register, the new data is written over the previous data and is transferred to the shift register.
setting of UART0CR1<IRDASEL>.
Table 16-9 TXD0 Pin Output
When UART0CR1<TXE> is "0"
From when "1" is written to
UART0CR1<TXE> to when the trans-
mitted data is written to TD0BUF
When the STOP, IDLE0 or SLEEP0
mode is active
Condition
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IRDASEL="0"
H level
TXD0 pin output
IRDASEL="1"
L level
TMP89FM42A