HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 333

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

Figure 10.14 shows an example of the operation when receiving in asynchronous mode.
10.3.5
In synchronous mode, SCI3 transmits and receives data in synchronization with clock pulses. This
mode is suitable for high-speed serial communication.
SCI3 has separate transmission and reception units, allowing full-duplex communication with a
shared clock.
As the transmission and reception units are both double-buffered, data can be written during
transmission and read during reception, making possible continuous transmission and reception.
Serial
data
RDRF
FER
LSI
operation
User
processing
Figure 10.14 Example of Operation when Receiving in Asynchronous Mode
1
Operation in Synchronous Mode
Start
bit
0
D0
D1
Receive
1 frame
data
D7
(8-Bit Data, Parity, 1 Stop Bit)
Parity
0/1
bit
RXI request
Stop
bit
1
Start
bit
0
D0
RDRF
cleared to 0
RDR data read
1 frame
D1
Receive
data
D7
Parity
0/1
bit
Stop
bit
0
0 start bit
detected
Mark state
(idle state)
1
ERI request in
response to
framing error
Framing error
processing
327