p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 383

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

15.5.2
Figure 15.13 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 in asynchronous mode. Figure
15.12 shows an example of SCI operation for multiprocessor format reception.
MPIE
RDRF
RDR
value
MPIE
RDRF
RDR
value
Multiprocessor Serial Data Reception
1
1
Start
bit
Start
bit
(Example with 8-Bit Data, Multiprocessor Bit, One Stop Bit)
0
0
MPIE = 0
MPIE = 0
D0
D0
Figure 15.12 Example of SCI Receive Operation
ID1
D1
D1
Data (ID1)
Data (ID2)
RXI interrupt
request
(multiprocessor
interrupt)
generated
RXI interrupt
request
(multiprocessor
interrupt)
generated
D7
D7
(a) Data does not match station’s ID
(b) Data matches station’s ID
MPB
MPB
1
1
RDR data read and
RDRF flag cleared
to 0 in RXI interrupt
handling routine
RDR data read
and RDRF flag
cleared to 0 in
RXI interrupt
handling routine
Stop
bit
Stop
bit
1
1
Start
bit
Start
bit
0
0
Section 15 Serial Communication Interface (SCI)
D0
D0
If not this station’s ID,
MPIE bit is set to 1
again
Matches this station’s ID,
so reception continues, and
data is received in RXI
interrupt service routine
D1
D1
Data (Data 1)
Data (Data 2)
Rev. 1.00 Sep. 21, 2006 Page 345 of 658
ID2
ID1
D7
D7
MPB
MPB
0
0
RXI interrupt request is
not generated, and RDR
retains its state
Stop
bit
Stop
bit
1
1
MPIE bit set to 1
again
Idle state
(mark state)
Idle state
(mark state)
REJ09B0310-0100
Data 2
1
1