SH7261 Datasheet, PDF (748/1348 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 16 Serial Communication Interface with FIFO (SCIF)
In serial reception, the SCIF operates as described below.
1. The SCIF monitors the transmission line, and if a 0 start bit is detected, performs internal
synchronization and starts reception.
2. The received data is stored in SCRSR in LSB-to-MSB order.
3. The parity bit and stop bit are received.
After receiving these bits, the SCIF carries out the following checks.
A. Stop bit check: The SCIF checks whether the stop bit is 1. If there are two stop bits, only
the first is checked.
B. The SCIF checks whether receive data can be transferred from the receive shift register
(SCRSR) to SCFRDR.
C. Overrun check: The SCIF checks that the ORER flag is 0, indicating that the overrun error
has not occurred.
D. Break check: The SCIF checks that the BRK flag is 0, indicating that the break state is not
set.
If all the above checks are passed, the receive data is stored in SCFRDR.
Note: When a parity error or a framing error occurs, reception is not suspended.
4. If the RIE bit in SCSCR is set to 1 when the RDF or DR flag changes to 1, a receive-FIFO-
data-full interrupt (RXI) request is generated. If the RIE bit or the REIE bit in SCSCR is set to
1 when the ER flag changes to 1, a receive-error interrupt (ERI) request is generated. If the
RIE bit or the REIE bit in SCSCR is set to 1 when the BRK or ORER flag changes to 1, a
break reception interrupt (BRI) request is generated.
Figure 16.8 shows an example of the operation for reception.
Serial data
RDF
1
Start
bit
0 D0
Data ^Parity
bit
Stop Start
bit bit
D1
D7 0/1 1 0 D0
Data ^{Parity Stop}
bit bit
1
D1
D7
0/1
1
Idle state
(mark state)
FER
RXI interrupt
request
One frame
Data read and RDF flag
read as 1 then cleared to 0
by RXI interrupt handler
ERI interrupt request
generated by receive
error
Figure 16.8 Example of SCIF Receive Operation (8-Bit Data, Parity, 1 Stop Bit)
Rev. 2.00 Sep. 07, 2007 Page 716 of 1312
REJ09B0320-0200