Hitachi H8/3692 ユーザーズマニュアル
Rev. 1.0, 07/01, page 188 of 372
14.3.7
Serial Status Register (SSR)
SSR is a register containing status flags of the SCI and multiprocessor bits for transfer. 1 cannot
be written to flags TDRE, RDRF, OER, PER, and FER; they can only be cleared.
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
Indicates 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