Rev. 1.0, 09/02, page 339 of 568
Yes
<End>
[1]
No
Initialization
Start transmission/reception
[5]
Error processing
[3]
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
Yes
ORER = 1
All data received?
[2]
Read TDRE flag in SSR
No
Yes
TDRE = 1
Write transmit data to TDR and
clear TDRE flag in SSR to 0
No
Yes
RDRF = 1
Read ORER flag in SSR
[4]
Read RDRF flag in SSR
Clear TE and RE bits in SCR to 0
[1]
SCI initialization:
The TxD pin is designated as the
transmit data output pin, and the RxD
pin is designated as the receive data
input pin, enabling simultaneous
transmit and receive operations.
[2]
SCI status check and transmit data
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.
Transition of the TDRE flag from 0 to
1 can also be identified by a TXI
interrupt.
[3]
Receive error processing:
If a receive error occurs, read the
ORER flag in SSR, and after
performing the appropriate error
processing, clear the ORER flag to 0.
Transmission/reception cannot be
resumed if the ORER flag is set to 1.
[4]
SCI status check and receive data
read:
Read SSR and check that the RDRF
flag is set to 1, then read the receive
data in RDR and clear the RDRF flag
to 0. Transition of the RDRF flag from
0 to 1 can also be identified by an RXI
interrupt.
[5]
Serial transmission/reception
continuation procedure:
To continue serial transmission/
reception, before the MSB (bit 7) of
the current frame is received, finish
reading the RDRF flag, reading RDR,
and clearing the RDRF flag to 0.
Also, before the MSB (bit 7) of the
current frame is transmitted, read 1
from the TDRE flag to confirm that
writing is possible. Then write data to
TDR and 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. Also, the RDRF flag
is cleared automatically when the
DTC is activated by a receive data full
interrupt (RXI) request and the RDR
value is read.
Note:
*
When switching from transmit or receive operation to simultaneous
transmit and receive operations, first clear the TE bit and RE bit to 0,
then set both these bits to 1 simultaneously.
Figure 14.20 Sample Flowchart of Simultaneous Serial Transmit and Receive Operations
Summary of Contents for H8S/2627
Page 22: ...Rev 1 0 09 02 page xx of xxxvi Index 565 ...
Page 30: ...Rev 1 0 09 02 page xxviii of xxxiv ...
Page 36: ...Rev 1 0 09 02 page xxxiv of xxxiv Table 23 9 Flash Memory Characteristics 561 ...
Page 82: ...Rev 1 0 09 02 page 46 of 568 ...
Page 88: ...Rev 1 0 09 02 page 52 of 568 ...
Page 98: ...Rev 1 0 09 02 page 62 of 568 ...
Page 156: ...Rev 1 0 09 02 page 120 of 568 ...
Page 390: ...Rev 1 0 09 02 page 354 of 568 ...
Page 480: ...Rev 1 0 09 02 page 444 of 568 ...
Page 512: ...Rev 1 0 09 02 page 476 of 568 ...
Page 528: ...Rev 1 0 09 02 page 492 of 568 ...
Page 580: ...Rev 1 0 09 02 page 544 of 568 ...