Hitachi H8/3692 ユーザーズマニュアル

Rev. 1.0, 07/01, page 198 of 372

No

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 and

set PCR to 1

Clear TE bit in SCR3 to 0

TDRE = 1

All data transmitted?

TEND = 1

Break output?

[1] 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. Checking and 
clearing of the TDRE flag is 
automatic.

[2] 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. 

[3] To output a break at the end of 

serial transmission, after setting 
PCR to 1 and clearing PDR to 0, 
clear TxD in PMR1 to 0, then clear 
the TE bit in VSCR3 to 0.

End