HD6417144 RENESAS [Renesas Technology Corp], HD6417144 Datasheet - Page 476

• Manufacturer Part Number: HD6417144
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

13. Serial Communication Interface (SCI)
Figure 13.7 shows a sample flowchart for transmission in asynchronous mode.
Rev.4.00 Mar. 27, 2008 Page 432 of 882
REJ09B0108-0400
and clear TDRE flag in SSR to 0
as an output port with the PFC
Write transmit data to TDR
Clear TE bit in SCR to 0;
Read TDRE flag in SSR
Read TEND flag in SSR
All data transmitted?
Start transmission
select the TxD pin
Figure 13.7 Sample Serial Transmission Flowchart
Break output?
Clear DR to 0
Initialization
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
Set the TxD pin using the PFC.
After the TE bit is set to 1, a frame
period of 1s is output, and
transmission is enabled. This action
doesn't initiate immediate data
transmission.
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 then clear
the TDRE flag to 0. Checking and
clearing of the TDRE flag is
automatic when the DMAC or DTC
is activated by a transmit data
empty interrupt (TXI) request, and
data is written to TDR.
transmission:
To output a break in serial
transmission, first clear the port
data register (DR) to 0, then clear
the TE bit to 0 in SCR and use the
PFC to select the TxD pin as an