h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 399

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

13.3.7
SSR is a register containing status flags of the SCI and multiprocessor bits for transfer. 1 cannot
be written to flags TDRE, RDRF, ORER, PER, and FER; they can only be cleared. Some bit
functions of SSR differ between normal serial communication interface mode and smart card
interface mode.
• Normal Serial Communication Interface Mode (When SMIF in SCMR is 0)
Bit
7
6
Bit Name
TDRE
RDRF
Serial Status Register (SSR)
Initial
Value
1
0
R/W
R/W
R/W
Receive Data Register Full
Description
Transmit Data Register Empty
Displays whether TDR contains transmit data.
[Setting conditions]
•
•
[Clearing conditions]
•
•
Indicates that the received data is stored in RDR.
[Setting condition]
•
[Clearing conditions]
•
•
The RDRF flag is not affected and retains their previous
values when the RE bit in SCR is cleared to 0.
When the TE bit in SCR is 0
When data is transferred from TDR to TSR and data
can be written to TDR
When 0 is written to TDRE after reading TDRE = 1
When the DTC is activated by a TXI interrupt
request and writes data to TDR
When serial reception ends normally and receive
data is transferred from RSR to RDR
When 0 is written to RDRF after reading RDRF = 1
When the DTC is activated by an RXI interrupt and
transferred data from RDR
Section 13 Serial Communication Interface (SCI)
Rev. 2.00 Dec. 05, 2005 Page 361 of 724
REJ09B0200-0200