SH7018 Datasheet, PDF (260/431 Pages) Renesas Technology Corp – SuperH™ RISC engine

Figures 12.13 show examples of SCI1 receive operation using a multiprocessor format.
Serial
data
Start Data
1 _{bit (ID1)}
0 D0 D1
Stop Start Data
MPB bit bit (data 1)
D7 1 1 0 D0 D1
Stop
MPB bit
1
D7 0 1 Idling
(marking)
MPB
MPIE
RDRF
RDR1
value
ID1
RxI interrupt request
(multiprocessor
interrupt), MPIE = 0
RxI interrupt handler
reads data in RDR1
and clears RDRF to 0
Not station’s
ID, so MPIE is
set to 1 again
(a) ID Does Not Match
No RxI interrupt,
RDR1 maintains
state
Serial
data
Start Data
1 _{bit (ID2)}
0 D0 D1
Stop Start Data
MPB bit bit (data 2)
D7 1 1 0 D0 D1
Stop
MPB bit
1
D7 0 1 Idling
(marking)
MPB
MPIE
RDRF
RDR1
value
ID1
ID2
Data2
RxI interrupt request
(multiprocessor
interrupt), MPIE = 0
RxI interrupt handler Station’s ID, so receiving MPIE
reads data in RDR1
continues, with data bit is again
and clears RDRF to 0
received by the RxI
set to 1
interrupt processing routine
(b) ID Matches
Figure 12.13 SCI1 Receive Operation (8-Bit Data with Multiprocessor Bit and
One Stop Bit)
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