HD6437020 Datasheet, PDF (397/507 Pages) Hitachi Semiconductor – SuperH™ RISC engine

Start
1 _bit
Stop Start
Data ID1 MPB bit bit
Stop
Data 1 _MPB bit
1
Serial
data
0 D₀ D₁
D₇ 1 1 0 D₀ D₁
D₇ 0 1 ^{Idle (mark}
state)
MPB
MPIE
RDRF
RDR
value
RXI request,
(multiprocessor
interrupt) MPIE = 0
RXI interrupt
handler reads data
in RDR and clears
RDRF to 0
ID1
Not own ID,
so MPIE is
set to 1 again
No RXI
interrupt,
RDR maintains
state
Figure 13.13 Example of SCI Receive Operation (own ID matches data) (8-bit data with
multiprocessor bit and one stop bit) (cont)
13.3.4 Clocked Synchronous Operation
In the clocked synchronous mode, the SCI transmits and receives data in synchronization with
clock pulses. This mode is suitable for high-speed serial communication.
The SCI transmitter and receiver share the same clock but are otherwise independent, so full
duplex communication is possible. The transmitter and receiver are also double buffered, so
continuous transmitting or receiving is possible by reading or writing data while transmitting or
receiving is in progress.
Figure 13.14 shows the general format in clocked synchronous serial communication.
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