tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 245

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

RA001
16.12.5 Transmit busy flag
16.12.6Transmit Buffer Full
UART0CR1<TXE>
TXD0 pin input
UART0SR<TBFL>
UART0SR<TBSY>
INTTXD0 interrupt
request
Writing of TD0BUF
UART0CR1<TXE>
TXD0 pin input
UART0SR<TBFL>
UART0SR<TBSY>
INTTXD0 interrupt
request
Writing of TD0BUF
UART0SR<TBSY> is cleared to "0". When transmission is restarted after data is written into TD0BUF,
UART0SR<TBSY> is set to "1". At this time, an INTTXD0 interrupt request is generated.
mission is started, UART0SR<TBFL> is cleared to "0". At this time, an INTTXD0 interrupt request is gener-
ated.
Figure 16-16 Transmit Busy Flag and Occurrence of Transmit Buffer Full
If transmission is completed with no waiting data in TD0BUF (when UART0SR<TBFL>="0"),
When TD0BUF has no data, or when data in TD0BUF is transferred to the transmit shift register and trans-
Writing data into TD0BUF sets UART0SR<TBFL> to "1".
Writing of
Writing of
data A
data A
Figure 16-17 Occurrence of Transmit Buffer Full
Start Bit0
Start Bit0
Writing of
data B
Bit1
Bit1
Bit2
Bit2
Bit3
Data A
Bit3
Data A
Bit4
Bit4
Page 231
Bit5
Bit5
Bit6
Bit6
Bit7 Stop
Bit7 Stop Start Bit0
Writing of
data B
Bit1
Start Bit0
Bit2
Bit3
Data B
Bit1
Data B
Bit6
Bit6
Bit7 Stop
Bit7 Stop
TMP89FM42