Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
Rev. 3.00 Jan 25, 2006 page 444 of 872
REJ09B0286-0300
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.
However, the TDRE flag is checked
and cleared automatically when the
DTC is initiated by a transmit data
empty interrupt (TXI) request and
writes data to TDR. Similarly, the
RDRF flag is cleared automatically
when the DTC is initiated by a receive
data full interrupt (RXI) and reads
data from RDR.
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 16.23 Sample Flowchart of Simultaneous Serial Transmission and Reception
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...