HD64F3644PV Datasheet, PDF (339/551 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 10 Serial Communication Interface
Transmitting: Figure 10.11 shows an example of a flowchart for data transmission. This
procedure should be followed for data transmission after initializing SCI3.
Start
Read bit TDRE
1
in SSR
No
TDRE = 1?
Yes
Write transmit
data to TDR
2
Continue data
transmission?
Yes
No
Read bit TEND
in SSR
1. Read the serial status register (SSR)
and check that bit TDRE is set to 1,
then write transmit data to the transmit
data register (TDR). When data is
written to TDR, bit TDRE is cleared to 0
automatically.
2. When continuing data transmission,
be sure to read TDRE = 1 to confirm that
a write can be performed before writing
data to TDR. When data is written to
TDR, bit TDRE is cleared to 0
automatically.
3. If a break is to be output when data
transmission ends, set the port PCR to 1
and clear the port PDR to 0, then clear bit
TXD in PMR7 and bit TE in SCR3 to 0.
No
TEND = 1?
Yes
3
Break output?
No
Yes
Set PDR = 0,
PCR = 1
Clear bit TE to 0
in SCR3
End
Figure 10.11 Example of Data Transmission Flowchart (Asynchronous Mode)
Rev. 6.00 Sep 12, 2006 page 317 of 526
REJ09B0326-0600