HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 404

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

In receiving, the SCI operates as follows:
1. The SCI synchronizes with serial clock input or output and initializes internally.
2. Receive data is shifted into the RSR in order from the LSB to the MSB. After receiving the
data, the SCI checks that RDRF is 0 so that receive data can be loaded from the RSR into the
ORER
RDRF
Serial
Serial
clock
data
RXI request
Receive direction
Figure 13.18 Sample Flowchart for Serial Receiving (cont)
Bit 7
Figure 13.19 Example of SCI Receive Operation
and clears RDRF to 0
RXI interrupt handler
Bit 0
reads data in RDR
No
1 frame
Clear ORER bit of SSR to 0
Overrun error handling
Bit 7
Error handling
ORER = 1?
End
RXI request
Bit 0
Yes
Bit 1
Bit 6
error, ERI
Overrun
request
HITACHI 391
Bit 7