Datasheet

Table Of Contents
Section 17 Serial Communications Interface 3 (SCI3, IrDA)
Rev. 2.00 Jul. 04, 2007 Page 358 of 692
REJ09B0309-0200
17.3.7 Serial Status Register (SSR)
SSR consists of status flags of the SCI3 and multiprocessor bits for transfer. 1 cannot be written to
flags TDRE, RDRF, OER, PER, and FER; they can only be cleared.
SSR is initialized to H'84 by a reset or in standby mode, watch mode, or module standby mode.
Bit Bit Name
Initial
Value
R/W Description
7 TDRE 1 R/(W)* Transmit Data Register Empty
Indicates that transmit data is stored in TDR.
[Setting conditions]
The TE bit in SCR is 0
Data is transferred from TDR to TSR
[Clearing conditions]
Writing of 0 to bit TDRE after reading TDRE = 1
The transmit data is written to TDR
6 RDRF 0 R/(W)* Receive Data Register Full
Indicates that the received data is stored in RDR.
[Setting condition]
Serial reception ends normally and receive data is
transferred from RSR to RDR
[Clearing condition]
Writing of 0 to bit RDRF after reading RDRF = 1
When data is read from RDR
If an error is detected in reception, or if the RE bit in
SCR has been cleared to 0, RDR and bit RDRF are not
affected and retain their previous state.
Note that if data reception is completed while bit RDRF
is still set to 1, an overrun error (OER) will occur and
the receive data will be lost.