Datasheet

Section 13 Serial Communication Interface 3 (SCI3)
Rev.4.00 Nov. 02, 2005 Page 170 of 304
REJ09B0143-0400
13.3.7 Serial Status Register (SSR)
SSR is a register containing 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.
Bit Bit Name Initial Value R/W Description
7 TDRE 1 R/W Transmit Data Register Empty
Displays whether TDR contains transmit data.
[Setting conditions]
• When the TE bit in SCR3 is 0
• When data is transferred from TDR to TSR
[Clearing conditions]
• When 0 is written to TDRE after reading TDRE
= 1
• When 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]
• When serial reception ends normally and
receive data is transferred from RSR to RDR
[Clearing conditions]
• When 0 is written to RDRF after reading RDRF
= 1
• When data is read from RDR
5 OER 0 R/W Overrun Error
[Setting condition]
• When an overrun error occurs in reception
[Clearing condition]
• When 0 is written to OER after reading OER = 1