Figure 16.12 Sample Serial Reception Flowchart (1) - Renesas H8S/2158 User Manual

Initialization
Start reception
Read ORER, PER, and
FER flags in SSR
PER ∨ FER ∨ ORER = 1
No
Read RDRF flag in SSR
No
RDRF = 1
Yes
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
All data received?
Yes
Clear RE bit in SCR to 0
<End>

Figure 16.12 Sample Serial Reception Flowchart (1)

Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
[1] SCI initialization:
[1]
[2] [3] Receive error processing and break
[2]
Yes
[3]
Error processing
(Continued on next page)
[4]
[4] SCI status check and receive data read:
[5] Serial reception continuation procedure:
[5]
The RxD pin is automatically
designated as the receive data input
pin.
detection:
If a receive error occurs, read the
ORER, PER, and FER flags in SSR to
identify the error. After performing the
appropriate error processing, ensure
that the ORER, PER, and FER flags are
all cleared to 0. Reception cannot be
resumed if any of these flags are set to
1. In the case of a framing error, a
break can be detected by reading the
value of the input port corresponding to
the RxD pin.
Read SSR and check that RDRF = 1,
then read the receive data in RDR and
clear the RDRF flag to 0. Transition of
the RDRF flag from 0 to 1 can also be
identified by an RXI interrupt.
To continue serial reception, before the
stop bit for the current frame is
received, read the RDRF flag, read
RDR, and clear the RDRF flag to 0.
However, the RDRF flag is cleared
automatically when the DTC is initiated
by an RXI interrupt and reads data from
RDR.
Legend:
∨: Logical add (OR)
Rev. 3.00 Jan 25, 2006 page 429 of 872
REJ09B0286-0300