h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 492

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 15 Serial Communication Interface (SCI, IrDA)
15.3.4
In synchronous mode, data is transmitted or received in synchronization with clock pulses, making
it suitable for high-speed serial communication.
Inside the SCI, the transmitter and receiver are independent units, enabling full-duplex
communication by use of a common clock. Both the transmitter and the receiver also have a
double-buffered structure, so that data can be read or written during transmission or reception,
enabling continuous data transfer.
Figure 15.14 shows the general format for synchronous serial communication.
In synchronous serial communication, data on the transmission line is output from one falling edge
of the serial clock to the next. Data is guaranteed valid at the rising edge of the serial clock.
In synchronous serial communication, one character consists of data output starting with the LSB
and ending with the MSB. After the MSB is output, the transmission line holds the MSB state.
In synchronous mode, the SCI receives data in synchronization with the rising edge of the serial
clock.
Data Transfer Format
A fixed 8-bit data format is used.
No parity or multiprocessor bits are added.
Rev. 4.00 Jun 06, 2006 page 438 of 1004
REJ09B0301-0400
Note: * High except in continuous transfer
Serial
clock
Serial
data
Operation in Synchronous Mode
Don’t care
*
Figure 15.14 Data Format in Synchronous Communication
LSB
Bit 0
Bit 1
One unit of transfer data (character or frame)
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
MSB
Don’t care
*