r5f71374an80fpv Renesas Electronics Corporation., r5f71374an80fpv Datasheet - Page 620

• Manufacturer Part Number: r5f71374an80fpv
• Description: 32-bit Risc Microcomputer Superh?? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

Section 14 Serial Communication Interface (SCI)
14.7
14.7.1
The TDRE flag in the serial status register (SCSSR) is a status flag indicating transferring of
transmit data from SCTDR into SCTSR. The SCI sets the TDRE flag to 1 when it transfers data
from SCTDR to SCTSR.
Data can be written to SCTDR regardless of the TDRE bit status.
If new data is written in SCTDR when TDRE is 0, however, the old data stored in SCTDR will be
lost because the data has not yet been transferred to SCTSR. Before writing transmit data to
SCTDR, be sure to check that the TDRE flag is set to 1.
14.7.2
If multiple receive errors occur at the same time, the status flags in SCSSR are set as shown in
table 14.18. When an overrun error occurs, data is not transferred from the receive shift register
(SCRSR) to the receive data register (SCRDR) and the received data will be lost.
Table 14.18 SCSSR Status Flag Values and Transfer of Received Data
Rev. 1.00 Sep. 21, 2007 Page 594 of 1124
REJ09B0402-0100
Receive Errors Generated
Overrun error
Framing error
Parity error
Overrun error + framing error
Overrun error + parity error
Framing error + parity error
Overrun error + framing error + parity error
Usage Notes
SCTDR Writing and TDRE Flag
Multiple Receive Error Occurrence
RDRF
1
0
0
1
1
0
1
SCSSR Status Flags
ORER
1
0
0
1
1
0
1
0
1
0
1
0
1
1
FER
PER
0
0
1
0
1
1
1
Receive Data
Transfer from
SCRSR to
SCRDR
Not transferred
Transferred
Transferred
Not transferred
Not transferred
Transferred
Not transferred