SH7708 Datasheet, PDF (391/625 Pages) Renesas Technology Corp – SuperH™ RISC engine

Figures 13.13 (a) and (b) show examples of SCI receive operation using a multiprocessor format.
Start Data
1 _bit (ID1)
Serial
data
0 D₀ D₁
MPIE
Stop Start Data
MPB bit bit (data 1)
D₇ 1 1 0 D₀ D₁
Stop
MPB bit
D₇ 0 1
1
Idle
(mark)
state
RDRF
RDR
value
ID1
RXI interrupt request
(multiprocessor interrupt),
MPIE = 0
RXI interrupt
handler reads RDR
data and clears
RDRF bit to 0
ID is not station’s No RXI interrupt,
ID, so MPIE bit is RDR state
set to 1 again
is maintained
Figure 13.13 (a) Example of SCI Receive Operation: Own ID Does Not Match
Data (8-Bit Data with Multiprocessor Bit and One Stop Bit)
Start Data
1 _bit (ID2)
Serial
data
0 D₀ D₁
MPIE
Stop Start Data
MPB bit bit (Data 2)
D₇ 1 1 0 D₀ D₁
Stop
MPB bit
D₇ 0 1
1
Idle
(mark)
state
RDRF
RDR
value
ID1
ID2
Data2
RXI interrupt
request
(multiprocessor
interrupt),
MPIE = 0
RXI interrupt handler
reads RDR data
and clears
RDRF bit to 0
ID is that of station,
so reception
continues unchanged
and data is received
by the RXI interrupt
handler
MPIE bit
set to 1
again
Figure 13.13 (b) Example of SCI Receive Operation: Own ID Matches Data
(8-BitDatawithMultiprocessor Bit and One Stop Bit)
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