How-To Guide

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 993 of 1852
Nov 30, 2020
RX23W Group 33. Serial Communications Interface (SCIg, SCIh)
ORER Flag (Overrun Error Flag)
Indicates that an overrun error has occurred during reception and the reception ends abnormally.
[Setting condition]
When the next data is received before receive data is read from the RDR register
In the RDR register, the receive data prior to an overrun error occurrence is retained, but data received following the
overrun error occurrence is lost. When the ORER flag is set to 1, subsequent serial reception cannot be performed.
[Clearing condition]
When 0 is written to the ORER flag after reading ORER = 1
When setting the ORER flag to 0 to complete the interrupt handling, refer to
section 15.4.1.2, Operation of
Status Flags for Level-Detected Interrupts
.
Even when the SCR.RE bit is set to 0, the ORER flag is not affected and retains its previous value.
RDRF Flag (Receive Data Full Flag)
Indicates whether the RDR register has received data.
[Setting condition]
When data has been received normally, and transferred from the RSR register to the RDR register
[Clearing condition]
When data is read from the RDR register
TDRE Flag (Transmit Data Empty Flag)
Indicates whether the TDR register has data to be transmitted.
[Setting condition]
When data is transferred from the TDR register to the TSR register
[Clearing condition]
When data is written to the TDR register