DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 478

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

12.6.4
Figure 12.21 shows an example of SCI operation for reception in clocked synchronous mode. In
serial reception, the SCI operates as described below.
1. The SCI performs internal initialization synchronous with a synchronous clock input or output,
2. If an overrun error occurs (when reception of the next data is completed while the RDRF flag
3. If reception is completed successfully, the RDRF bit in SSR is set to 1, and receive data is
Reception cannot be resumed while a receive error flag is set to 1. Accordingly, clear the ORER,
FER, PER, and RDRF bits to 0 before resuming reception. Figure 12.22 shows a sample flow chart
for serial data reception.
When the internal clock is selected during reception, the synchronization clock will be output until
an overrun error occurs or the RE bit is cleared. To receive data in frame units, a dummy data of
one frame must be transmitted simultaneously.
Rev.7.00 Dec. 24, 2008 Page 424 of 698
REJ09B0074-0700
Synchronization
clock
Serial data
RDRF
ORER
starts receiving data, and stores the received data in RSR.
in SSR 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, and the
RDRF flag remains to be set to 1.
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 finished.
Serial Data Reception (Clocked Synchronous Mode)
RXI interrupt
request
generated
Figure 12.21 Example of SCI Operation in Reception
Bit 7
RDR data read and
RDRF flag cleared to 0
in RXI interrupt service
routine
Bit 0
1 frame
Bit 7
Bit 0
RXI interrupt request
generated
Bit 1
ERI interrupt request
generated by overrun
error
Bit 6
Bit 7