Hitachi H8/3692 ユーザーズマニュアル

Rev. 1.0, 07/01, page 205 of 372

No

Yes

Start transmission

Read TDRE flag in SSR

[1]

Write transmit data to TDR

No

Yes

No

Yes

Read TEND flag in SSR

[2]

Clear TE bit in SCR3 to 0

TDRE = 1

All data transmitted?

TEND = 1

[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. When data is 

written to TDR, the TDRE flag is 

automatically cleared to 0 and clocks are 

output to start the data transmission.

[2]

To continue serial transmission, be sure to 

read 1 from the TDRE flag to confirm that 

writing is possible, then write data to TDR.

When data is written to TDR, the TDRE flag 

is automatically cleared to 0.

End