Datasheet

Table Of Contents
Section 17 Serial Communications Interface 3 (SCI3, IrDA)
Rev. 2.00 Jul. 04, 2007 Page 385 of 692
REJ09B0309-0200
No
Yes
Start transmission
Read TDRE flag in SSR
Set SPC3 bit in SPCR or SPCR2 to 1
[1]
Write transmit data to TDR
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
Continue data transmission?
TEND = 1
Break output?
[1] Read SSR and check that the
TDRE flag is set to 1, then write
transmit data to TDR. When data is
written to TDR, the TDRE flag is
automaticaly cleared to 0.
(After the TE bit is set to 1, one
frame of 1 is output, then
transmission is possible.)
[2] To continue serial transmission,
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
automaticaly cleared to 0.
[3] To output a break in serial
transmission, after setting PCR to 1
and PDR to 0, clear the TE bit in
SCR to 0.
End
Figure 17.6 Sample Serial Transmission Flowchart (Asynchronous Mode)