SH7616 Datasheet, PDF (661/935 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7600 Series

Section 14 Serial Communication Interface with FIFO (SCIF)
The number of receive data bytes in SCFRDR can be found from the lower 8 bits of the FIFO data
count register (SCFDR).
SCFRDR Reading when Overrun Occurs: If a receive operation is continued despite the fact
that the receive FIFO data register (SCFRDR) contains 16 bytes of data, overrun will occur.
If SCFRDR is read in this state, the data that caused the overrun is read in the 17th read. The value
returned in the 18th and subsequent reads will be undefined.
Also note that, from the first SCFRDR read onward, the number of receive data bytes in SCFRDR
indicated by the lower 8 bits of the FIFO data count register (SCFDR) is one more than the actual
number of receive data bytes.
Rev. 2.00 Mar 09, 2006 page 635 of 906
REJ09B0292-0200