h8s-2158 Renesas Electronics Corporation., h8s-2158 Datasheet - Page 478

• Manufacturer Part Number: h8s-2158
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
Rev. 3.00 Jan 25, 2006 page 426 of 872
REJ09B0286-0300
and clear TDRE flag in SSR to 0
Write transmit data to TDR
Read TDRE flag in SSR
Read TEND flag in SSR
Clear TE bit in SCR to 0
All data transmitted?
Clear DR to 0 and
Start transmission
Break output?
set DDR to 1
Initialization
Figure 16.10 Sample Serial Transmission Flowchart
TDRE = 1
TEND = 1
<End>
Yes
Yes
Yes
Yes
No
No
No
No
[1]
[2]
[3]
[4]
[1] SCI initialization:
[2] SCI status check and transmit data
[3] Serial transmission continuation
[4] Break output at the end of serial
The TxD pin is automatically
designated as the transmit data
output pin.
After the TE bit is set to 1, a frame
of 1s is output, and transmission is
enabled.
write:
Read SSR and check that the
TDRE flag is set to 1, then write
transmit data to TDR and clear the
TDRE flag to 0.
procedure:
To continue serial transmission,
read 1 from the TDRE flag to
confirm that writing is possible,
then write data to TDR, and clear
the TDRE flag to 0. However, the
TDRE flag is checked and cleared
automatically when the DTC is
initiated by a transmit data empty
interrupt (TXI) request and writes
data to TDR.
transmission:
To output a break in serial
transmission, set DDR for the port
corresponding to the TxD pin to 1,
clear DR to 0, then clear the TE bit
in SCR to 0.