h8s-2111b Renesas Electronics Corporation., h8s-2111b Datasheet - Page 291

• Manufacturer Part Number: h8s-2111b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Table 12.9 SSR Status Flags and Receive Data Handling
Note:
RDRF*
1
0
0
1
1
0
1
*
No
No
ORER
1
0
0
1
1
0
1
The RDRF flag retains the state it had before data reception.
SSR Status Flag
Read receive data in RDR, and
clear RDRF flag in SSR to 0
PER ∨ FER ∨ ORER = 1
Read RDRF flag in SSR
Clear RE bit in SCR to 0
Read ORER, PER, and
All data received?
FER flags in SSR
Figure 12.9 Sample Serial Reception Flowchart (1)
Start reception
FER
0
1
0
1
0
1
1
Initialization
RDRF = 1
<End>
Yes
Yes
No
PER
0
0
1
0
1
1
1
(Continued on next page)
Error processing
Yes
[1]
[2]
[4]
[5]
Receive Data
Lost
Transferred to RDR
Transferred to RDR
Lost
Lost
Transferred to RDR
Lost
[3]
[1] SCI initialization:
[2] [3] Receive error processing and break
[4] SCI status check and receive data read:
[5] Serial reception continuation procedure:
[Legend]
∨ : Logical OR
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.
Rev. 1.00, 05/04, page 257 of 544
Receive Error Type
Overrun error
Framing error
Parity error
Overrun error + framing error
Overrun error + parity error
Framing error + parity error
Overrun error + framing error
+ parity error