h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 418

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

Section 13 Serial Communication Interface (SCI)
13.4.6
Figure 13.8 shows an example of operation for reception in asynchronous mode. In serial
reception, the SCI operates as described below.
1. The SCI monitors the communication line. If a start bit is detected, the SCI performs internal
2. If an overrun error occurs (when reception of the next data is completed while the RDRF flag
3. If a parity error is detected, the PER bit in SSR is set to 1 and receive data is transferred to
4. If a framing error is detected (when the stop bit is 0), the FER bit in SSR is set to 1 and receive
5. If reception is completed successfully, the RDRF bit in SSR is set to 1, and receive data is
Rev. 2.00 Dec. 05, 2005 Page 380 of 724
REJ09B0200-0200
synchronization, receives receive data in RSR, and checks the parity bit and stop bit.
is still set to 1), the ORER bit in SSR is set to 1. If the RIE bit in SCR is set to 1 at this time, an
ERI interrupt request is generated. Receive data is not transferred to RDR. The RDRF flag
remains to be set to 1.
RDR. If the RIE bit in SCR is set to 1 at this time, an ERI interrupt request is generated.
data is transferred to RDR. If the RIE bit in SCR is set to 1 at this time, an ERI interrupt
request is generated.
transferred to RDR. If the RIE bit in SCR is set to 1 at this time, an RXI interrupt request is
generated. Continuous reception is possible because the RXI interrupt routine reads the receive
data transferred to RDR before reception of the next receive data has been completed.
RDRF
FER
Serial Data Reception (Asynchronous Mode)
1
Start
bit
0
D0
Figure 13.8 Example of SCI Operation in Reception
(Example with 8-Bit Data, Parity, One Stop Bit)
D1
1 frame
Data
D7
RXI interrupt
request
generated
Parity
bit
0/1
Stop
bit
1
Start
bit
0
RDR data read and RDRF
flag cleared to 0 in RXI
interrupt service routine
D0
D1
Data
D7
Parity
bit
0/1
ERI interrupt request
generated by framing
error
Stop
bit
0
Idle state
(mark state)
1