SH7011 Datasheet, PDF (235/292 Pages) Renesas Technology Corp – CMOS single-chip microprocessors

Figures 12.12 show examples of SCI receive operation using a multiprocessor format.
Start Data
1 _{bit (ID1)}
Serial
data
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
RDR
value
RxI interrupt request
(multiprocessor
interrupt), MPIE = 0
ID1
RxI interrupt handler
reads data in RDR
and clears RDRF to 0
Not station’s
ID, so MPIE is
set to 1 again
No RxI interrupt,
RDR maintains
state
(a) ID Does Not Match
Start Data
1 _{bit (ID2)}
Serial
data
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
RDR
value
ID1
ID2
Data2
RxI interrupt request
(multiprocessor
interrupt), MPIE = 0
RxI interrupt handler Station’s ID, so receiving MPIE
reads data in RDR
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 12.12 SCI Receive Operation (8-Bit Data with Multiprocessor Bit and One Stop Bit)
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