Rev. 1.0, 02/00, page 465 of 1141
TDRE
Description
0
The next transmit data is in ICDR (ICDRT), or transmission cannot be started
[Clearing conditions]
(Initial value)
1. When transmit data is written in ICDR (ICDRT) in transmit mode (TRS = 1)
2. When a stop condition is detected in the bus line state after a stop condition is
issued with the I
2
C bus format or serial format selected
3. When a stop condition is detected with the I
2
C bus format selected
4. In receive mode (TRS = 0)
(A 0 write to TRS during transfer is valid after reception of a frame containing an
acknowledge bit)
1
The next transmit data can be written in ICDR (ICDRT)
[Setting conditions]
1. In transmit mode (TRS = 1), when a start condition is detected in the bus line state
after a start condition is issued in master mode with the I
2
C bus format or serial
format selected
2. In transmit mode (TRS = 1) when formatless transfer is selected
3. When data is transferred from ICDRT to ICDRS
(Data transfer from ICDRT to ICDRS when TRS = 1 and TDRE = 0, and ICDRS is
empty)
4. When a switch is made from receive mode (TRS = 0) to transmit mode (TRS = 1)
after detection of a start condition
RDRF
Description
0
The data in ICDR (ICDRR) is invalid
(Initial value)
[Clearing condition]
When ICDR (ICDRR) receive data is read in receive mode
1
The ICDR (ICDRR) receive data can be read
[Setting condition]
When data is transferred from ICDRS to ICDRR
(Data transfer from ICDRS to ICDRR in case of normal termination with TRS = 0 and
RDRF = 0)