SH7727 Datasheet, PDF (727/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 20 Serial IO (SIOF)
At that time, make sure to set the watermark value so as not to receive FIFO full nor overflow
when receive operation.
Example: When 12 empty slots are set to receive FIFO, read 12 data from receive FIFO with
DMA auto request by receive FIFO transfer interrupt (SIFRXI).
Etc.
(1) Not to use DMA 16 bytes transfer. (See section 14.3.4, DMA Transfer Types.)
(2) Recommend DMA auto request for SIOF access. When from CPU, not to use continuous
access.
(3) When newly use SIOF after transmit/receive operation, proceed transfer operation after
transmit reset (TXRST) or receive reset (RXRST).
Rev. 5.00 Dec 12, 2005 page 655 of 1034
REJ09B0254-0500