12
12-45
Ver.0.10
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 M32170F3VFP
Страница 19: ...CHAPTER 1 CHAPTER 1 OVERVIEW 1 1 Outline of the 32170 1 2 Block Diagram 1 3 Pin Function 1 4 Pin Layout ...
Страница 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Страница 56: ...2 2 14 Ver 0 10 This is a blank page ...
Страница 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Страница 192: ...6 6 58 Ver 0 10 INTERNAL MEMORY 6 9 Precautions to Be Taken When Rewriting Flash Memory This is a blank page ...
Страница 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Страница 498: ...10 10 228 Ver 0 10 MULTIJUNCTION TIMERS 10 9 TOM Output related 16 bit Timer This is a blank page ...
Страница 550: ...11 11 52 Ver 0 10 A D CONVERTERS 11 4 Precautions on Using A D Converters This is a blank page ...
Страница 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Страница 710: ...14 14 16 Ver 0 10 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 746: ...16 16 20 Ver 0 10 WAIT CONTROLLER 16 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 757: ...CHAPTER 18 CHAPTER 18 OSCILLATION CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit ...
Страница 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Страница 798: ...19 19 36 Ver 0 10 JTAG 19 6 Precautions about Board Design when Connecting JTAG This is a blank page ...
Страница 830: ...21 21 24 Ver 0 10 PRELIMINARY PRELIMINARY This is a blank page ELECTRICAL CHARACTERISTICS 21 5 AC Characteristics ...
Страница 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Страница 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 837: ...Appendix 2 1 32170 Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...