Multiprocessor Serial Data Reception; Figure 16.12 Example Of Sci Operation In Reception (Example With 8-Bit Data, Multiprocessor Bit, One Stop Bit) - Renesas H8S/2437 Hardware Manual

16.5.2

Multiprocessor Serial Data Reception

Figure 16.13 shows a sample flowchart for multiprocessor serial data reception. If the MPIE bit in
SCR is set to 1, data is skipped until data with a 1 multiprocessor bit is sent. On receiving data
with a 1 multiprocessor bit, the receive data is transferred to RDR. An RXI interrupt request is
generated at this time. All other SCI operations are the same as those in asynchronous mode.
Figure 16.12 shows an example of SCI operation for multiprocessor format reception.
Start
bit
1
0 D0
MPIE
RDRF
RDR
value
MPIE = 0
Start
1 bit
0 D0
MPIE
RDRF
RDR
value
MPIE = 0
Figure 16.12 Example of SCI Operation in Reception (Example with 8-Bit Data,
Rev. 1.00, 09/03, page 456 of 704
Data (ID1)
MPB
D1 D7 1
RXI interrupt
request
(multiprocessor
interrupt)
generated
(a) Data does not match station's ID
Data (ID2)
MPB
D1 D7 1
ID1
RXI interrupt
request
(multiprocessor
interrupt)
generated
(b) Data matches station's ID
Multiprocessor Bit, One Stop Bit)
Stop Start Data (Data 1)
bit bit
1 0 D0 D1
RDR data read If not this station's ID,
and RDRF flag MPIE bit is set to 1
cleared to 0 in again
RXI interrupt
processing routine
Stop Start Data (Data 2)
bit bit
1 0 D0 D1
RDR data read and Matches this station's ID,
RDRF flag cleared so reception continues, and
to 0 in RXI interrupt data is received in RXI
processing routine interrupt processing routine
Stop
MPB bit
1
D7 0 1 Idle state
(mark state)
ID1
RXI interrupt request is
not generated, and RDR
retains its state
Stop
1
MPB bit
D7 0 1 Idle state
(mark state)
ID2 Data 2
MPIE bit set to 1
again