12
12-48
Rev.1.0
SERIAL I/O
12.6 Transmit Operation in UART Mode
12.6 Transmit Operation in UART Mode
12.6.1 Setting the UART Baud Rate
The baud rate (data transfer rate) during UART mode is determined by a transmit/receive shift
clock. In UART mode, the source for this transmit/receive shift clock is always the internal clock
regardless of how the internal/external clock select bit (SIO Transmit/Receive Mode Register bit
D11) is set.
(1) Calculating the UART mode baud rate
After being divided by the clock divider, f(BCLK) is fed into the Baud Rate Generator (BRG), after
which it is further divided by 16 to produce a transmit/receive shift clock. The clock divider's
divide-by value is selected from 1, 8, 32, or 256(note) using the SIO Transmit Control Register's
CDIV (baud rate generator count source select) bits (D2, D3). The Baud Rate Generator divides
the clock it received from the clock divider by (baud rate register set value + 1) and further divides
the resulting clock by 16 to produce a transmit/receive shift clock.
During UART mode (in which the internal clock is always used), the baud rate is calculated using
the equation below.
1 (BCLK)
Baud rate =
[bps]
Clock divider's divide-by value
×
(baud rate register set value + 1)
×
16
Baud rate register set value = H'00 to H'FF (Note)
Clock divider's divide-by value = 1, 8, 32, or 256
Note: If the divide-by value selected for the baud rate generator count source is "1" (i.e., f(BCLK)
itself), make sure the baud rate register value you set is equal to or greater than 7.
Содержание 32172
Страница 20: ... This is a blank page 16 ...
Страница 21: ...1 1 Overview 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Layout CHAPTER 1 CHAPTER 1 OVERVIEW ...
Страница 44: ...1 1 24 Rev 1 0 This is a blank page Overview 1 4 Pin Layout ...
Страница 58: ...2 2 14 Rev 1 0 This is a blank page CPU 2 6 Data Formats ...
Страница 122: ...4 4 26 Rev 1 0 This is a blank page EIT 4 13 Precautions on EIT ...
Страница 200: ...7 7 6 Rev 1 0 This is a blank page RESET 7 4 Precautions to Be Taken Immediately after Reset ...
Страница 240: ...8 8 40 Rev 1 0 This is a blank page INPUT OUTPUT PORTS AND PIN FUNCTIONS 8 5 Precautions on Input Output Ports ...
Страница 298: ...9 9 58 Rev 1 0 This is a blank page DMAC 9 4 Precautions on Using DMAC ...
Страница 416: ...10 10 118 Rev 1 0 This is a blank page INPUT OUTPUT TIMERS 10 6 TOM Output Related 16 bit Timers ...
Страница 658: ...14 14 16 Rev 1 0 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 718: ...16 16 16 Rev 1 0 This is a blank page D A CONVERTERS 16 3 Functional Description of the D A Converters ...
Страница 766: ...18 18 22 Rev 1 0 WAIT CONTROLLER 18 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 776: ...19 19 10 Rev 1 0 RAM BACKUP MODE 19 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 777: ...CHAPTER 20 CHAPTER 20 OSCILLATION CIRCUIT 20 1 Oscillator Circuit 20 2 Clock Generator Circuit ...
Страница 782: ...20 20 6 Rev 1 0 OSCILLATION CIRCUIT 20 2 Clock Generator Circuit This is a blank page ...
Страница 856: ...23 23 26 Rev 1 0 This is a blank page ELECTRICAL CHARACTERISTICS 23 6 AC Characteristics ...
Страница 857: ...24 1 A D Conversion Characteristics CHAPTER 24 CHAPTER 24 STANDARD CHARACTERISTICS ...
Страница 859: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 861: ...Appendix 2 1 M32R E Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 865: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...