3. Serial Communication Interface (SCI)
The H8/300L Series microcomputers provide serial communications interfaces that are
optimal for application embedded microcontrollers. There are three serial communications
interfaces provided by the H8/300L Series, namely 8/16-bit synchronous serial, 8-bit
synchronous with 32-byte buffer, and 8-bit synchronous/asynchronous serial interfaces.
Function: The SCI1 supports 8- and 16-bit clock synchronous serial data transfers.
• Data sizes of 8 and 16 bits can be selected.
• One of eight internal clocks (ø/1024, ø/256, ø/64, ø/32, ø/16, ø/8, ø/4, and ø/2)
or an external clock can be used as the clock source.
• Interrupts are generated on transfer completion and errors.
System clock ø
Serial mode register 1
Serial port register 1
Serial data register L1
Serial data register U1
Serial communications interface 1 interrupt request flag
Note: This figure shows the SCI1 used in the H8/3724 series.
(3 or 4 bits)