H838076R Datasheet, PDF (444/669 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Super Low Power Series

Section 16 Serial Communication Interface 4 (SCI4)
16.4.5 Data Reception
Figure 16.6 shows an example flowchart of data reception. Data reception should be performed as
the following procedure after the SCI4 initialization.
Initialization
Start reception (RE = 1)
Read ORER in SCSR4
ORER = 1?
No
Read RDRF in SCSR4
[1]
[2]
Yes
[3]
Error
processing
(Shown below)
[4]
[1] Pin SI4 functions as input pin for receive
data
[2][3] When a reception error occurs, read the ORER
flag in SCSR4 and then clears the ORER flag
to 0 after executing the error processing. When
the ORER flag is set to 1, both transmission
and reception cannot be restarted.
[4] After reading SCSR4 and confirming RDRF = 1,
read the receive data in RDR4. The RDRF flag
is automatically cleared to 0. Changes in the
RDRF flag from 0 to 1 can be notified by an RXI
interrupt.
[5] To consecutively receive data, reading the RDRF
flag and RDR4 must be completed before
receiving the MSB (bit 7) of the current frame.
No
RDRF = 1?
Yes
Read received data in RDR4
RDRF cleared to 0 automatically
Yes
Data transfer will
continue?
[5]
No
Clear RE bit in SCR4 to 0
<Reception completed>
Error processing
[3]
Overrun error processing
Clear ORER flag in SCSR4 to 0
<Completed>
Note: Hatching area indicates SCI internal operation.
Figure 16.6 Flowchart Example of Data Reception
Rev. 4.00 Aug 23, 2006 Page 372 of 594
REJ09B0093-0400