Datasheet

Section 20 Serial Communication Interface 3 (SCI3, IrDA)
REJ09B0465-0300 Rev. 3.00 Page 701 of 982
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
No
<End>
Yes
Start transmission
Read TDRE flag in SSR[1]
Write transmit data to TDR
Yes
No
No
Yes
Read TEND flag in SSR
[2]
No
Yes
[3]
Clear PDR to 0, set PCR to 1,
and clear PMR to 0
Clear TE bit in SCR3 to 0
TDRE = 1
Is data transmission continued?
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.
[2] To continue data 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.
If data is transferred to TDR by the
DTC with a transmit data empty
interrupt (TXI) request, the TDRE
flag is automatically checked and
cleared.
[3] To output a break at the end of
data transmission, clear PMR
corresponding to TxD to 0, after
setting PCR to 1 and PDR to 0,
then clear the TE bit in SCR3 to 0.
Figure 20.6 Sample Flowchart for Transmitting Data (Asynchronous Mode)