HD64336900G Datasheet, PDF (242/408 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

[1] Read SSR and check that the TDRE
Start transmission/reception
flag is set to 1, then write transmit
data to TDR.
When data is written to TDR, the
Read TDRE flag in SSR
[1]
TDRE flag is automatically cleared to
0.
[2] Read SSR and check that the RDRF
No
TDRE = 1
flag is set to 1, then read the receive
data in RDR.
When data is read from RDR, the
Yes
RDRF flag is automatically cleared to
0.
Write transmit data to TDR
[3] To continue serial transmission/
reception, before the MSB (bit 7) of
the current frame is received, finish
reading the RDRF flag, reading RDR.
Read OER flag in SSR
Also, before the MSB (bit 7) of the
current frame is transmitted, read 1
from the TDRE flag to confirm that
Yes
OER = 1
writing is possible. Then write data to
TDR.
When data is written to TDR, the
No
TDRE flag is automatically cleared to
0. When data is read from RDR, the
RDRF flag is automatically cleared to
Read RDRF flag in SSR
[2]
0.
[4] If an overrun error occurs, read the
No
RDRF = 1
OER flag in SSR, and after
[4]
performing the appropriate error
Yes
Overrun error
processing
processing, clear the OER flag to 0.
Transmission/reception cannot be
resumed if the OER flag is set to 1.
For overrun error processing, see
Read receive data in RDR
figure 14.14.
Yes
All data received?
[3]
No
Clear TE and RE bits in SCR to 0
<End>
Figure 14.15 Sample Flowchart of Simultaneous Serial Transmit and Receive Operations
(Clocked Synchronous Mode)
Rev. 1.00, 11/03, page 214 of 376