Datasheet

Table Of Contents
Section 17 Serial Communications Interface 3 (SCI3, IrDA)
Rev. 2.00 Jul. 04, 2007 Page 398 of 692
REJ09B0309-0200
17.6.1 Multiprocessor Serial Data Transmission
Figure 17.16 shows a sample flowchart for multiprocessor serial data transmission. For an ID
transmission cycle, set the MPBT bit in SSR to 1 before transmission. For a data transmission
cycle, clear the MPBT bit in SSR to 0 before transmission. All other SCI3 operations are the same
as those in asynchronous mode.
No
Yes
Start transmission
Read TDRE flag in SSR
Set SPC3 bit in SPCR or SPCR2 to 1
[1]
Set MPBT bit in SSR
Yes
No
No
Yes
Read TEND flag in SSR
[2]
No
Yes
[3]
Clear PDR to 0 and set PCR to 1
Clear TE bit in SCR to 0
TDRE = 1
Data transmission continued?
TEND = 1?
Break output?
Write transmit data to TDR
[1] Read SSR and check that the TDRE
flag is set to 1, set the MPBT bit in
SSR to 0 or 1, then write transmit
data to TDR. When data is written to
TDR, the TDRE flag is automatically
cleared to 0.
[2] To continue serial transmission, be
sure to read 1 from the TDRE flag to
confirm that writing is possible, then
write data to TDR. When data is
written to TDR, the TDRE flag is
automatically cleared to 0.
[3] To output a break in serial
transmission, set the port PCR to 1,
clear PDR to 0, then clear the TE bit
in SCR to 0.
End
Figure 17.16 Sample Multiprocessor Serial Transmission Flowchart