12
12-43
Ver.0.10
SERIAL I/O
12.5 Precautions on Using CSIO Mode
12.5 Precautions on Using CSIO Mode
• Settings of SIO Transmit/Receive Mode Register and SIO Baud Rate Register
The SIO Transmit/Receive Mode Register and SIO Baud Rate Register and the Transmit Control
Register's BRG count source select bit must always be set when not operating. When transmitting
or receiving data, be sure to check that transmission and/or reception under way has been
completed and clear the transmit and receive enable bits before you set the registers.
• Settings of Baud Rate (BRG) Register
If you selected f(BCLK) with the BRG clock source select bit, make sure the BRG register value you
set does not exceed 2 Mbps.
• About successive transmission
To transmit multiple data successively, set the next transmit data in the SIO Transmit Buffer
Register before transmission of the preceding data is completed.
• About reception
Because during CSIO mode the receive shift clock is derived from operation of the transmit circuit,
you need to execute transmit operation (by sending dummy data) even when you only want to
receive data. In this case, note that if the port function is set for TXD pin (by setting the operation
mode register to 1), dummy data is actually output from the pin.
• About successive reception
To receive multiple data successively, set data (dummy data) in the SIO Transmit Buffer Register
before the transmitter starts sending data.
• Transmit/receive operations using DMA
To transmit/receive data in DMA request mode, enable the DMAC to accept transfer requests (by
setting the DMA Mode Register) before you start serial communication.
• About the receive-finished bit
If a receive error (overrun error) occurs, the receive-finished bit cannot be cleared by reading out
the receive buffer register. In this case, it can only be cleared by clearing the receive enable bit.
Summary of Contents for M32170F3VFP
Page 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Page 56: ...2 2 14 Ver 0 10 This is a blank page ...
Page 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Page 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Page 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Page 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Page 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Page 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Page 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Page 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...