MB95630H Series
482
FUJITSU SEMICONDUCTOR LIMITED
MN702-00009-1v0-E
CHAPTER 22 UART/SIO
22.7 Registers
[bit2] RDRF: Receive data register full flag bit
This bit indicates the state of the UART/SIO serial input data register (RDRn).
When receive data is loaded to the RDRn register, this bit is set to "1".
When data in the RDRn register is read, this bit is cleared to "0".
[bit1] TCPL: Transmission completion flag bit
This bit indicates the data transmission state.
When serial transmission is completed, this bit is set to "1". However, when the UART/SIO serial output data
register (TDRn) contains data to be transmitted successively, this bit is not set to "1" even after one time of
transmission is completed.
Writing "0" to this bit clears it.
When transmission completion setting this bit to "1" and writing "0" to this bit to clear it occur
simultaneously, the former one is given priority.
Writing "1" to this bit has no effect on operation.
[bit0] TDRE: Transmit data register empty flag bit
This bit indicates the state of the UART/SIO serial output data register (TDRn).
When transmit data is written to the TDRn register, this bit is set to "0".
When transmit data is loaded to the shift register for the transmission and data transmission starts, this bit is
set to "1".
bit2
Details
Reading "0"
Indicates that there is no receive data in the RDRn register.
Reading "1"
Indicates that there is receive data in the RDRn register.
bit1
Details
Reading "0"
Indicates that data transmission has not been completed.
Reading "1"
Indicates that data transmission has been completed.
Writing "0"
Clears this bit.
Writing "1"
Has no effect on operation.
bit0
Details
Reading "0"
Indicates that there is transmit data in the TDRn register.
Reading "1"
Indicates that there is no transmit data in the TDRn register.