Datasheet

Table Of Contents
Section 18 Serial Communication Interface 4 (SCI4)
Rev. 2.00 Jul. 04, 2007 Page 418 of 692
REJ09B0309-0200
18.3.2 Serial Control/Status Register 4 (SCSR4)
SCSR4 indicates the operating state and error state, selects the clock source, and controls the
prescaler division ratio.
SCSR4 can be read from or written to by the CPU at any time. 1 cannot be written to flags TDRE,
RDRF, ORER, and TEND. To clear these flags to 0, 1 should be read from them in advance.
Bit Bit Name
Initial
Value
R/W Description
7 TDRE 1 R/(W)* Transmit Data Empty
Indicates that data is transferred from TDR4 to SR4
and the next serial transmit data can be written to
TDR4.
[Setting conditions]
The TE bit in SCR4 is 0
Data is transferred from TDR4 to SR4 and data can
be written to TDR4
[Clearing conditions]
Writing of 0 to bit TDRE after reading TDRE = 1
Data is written to TDR4
6 RDRF 0 R/(W)* Receive Data Full
Indicates that the receive data is stored in RDR4.
[Setting condition]
Serial reception ends normally and receive data is
transferred from SR4 to RDR4
[Clearing conditions]
Writing of 0 to bit RDRF after reading RDRF = 1
Data is read from RDR4