h8s-2169 Renesas Electronics Corporation., h8s-2169 Datasheet - Page 506

• Manufacturer Part Number: h8s-2169
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 15 Serial Communication Interface (SCI, IrDA)
Serial Data Transmission (Synchronous Mode): Figure 15.16 shows a sample flowchart for
serial transmission.
The following procedure should be used for serial data transmission.
Rev. 3.00 Jan 18, 2006 page 478 of 1044
REJ09B0280-0300
Write transmit data to TDR and
clear TDRE flag in SSR to 0
Read TDRE flag in SSR
Read TEND flag in SSR
Clear TE bit in SCR to 0
All data transmitted?
Start transmission
Initialization
TDRE = 1?
TEND = 1?
<End>
Figure 15.16 Sample Serial Transmission Flowchart
Yes
Yes
Yes
No
No
No
[3]
[2]
[1]
[1] SCI initialization:
[2] SCI status check and transmit data
[3] Serial transmission continuation
The TxD pin is automatically
designated as the transmit data output
pin.
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, be
sure to read 1 from the TDRE flag to
confirm that writing is possible, then
write data to TDR, and then clear the
TDRE flag to 0.
Checking and clearing of the TDRE
flag is automatic when the DTC is
activated by a transmit-data-empty
interrupt (TXI) request and data is
written to TDR.