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CHAPTER 20 UART2, UART3
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Using External Clock
If the EXT bit of the SMR2/SMR3 is set, an external clock is selected, which has to be connected to the
SCK2/SCK3 pin. The external clock is used in the same way as the machine clock to the baud rate reload
counter.
If One-to-one External Clock Input Mode (SMR2/SMR3:OTO) is selected the SCK2/SCK3 signal is
directly connected to the UART2, UART3 serial clock inputs. This is needed for the UART2, UART3
synchronous mode 2 operating as slave device.
Note, that in any case the resulting clock signal is synchronized to the machine clock in the UART2,
UART3 module. This means that indivisible clock rates will result in phase unstable signals.
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Counting Example
Assume the reload value is 832. The Figure 20.6-2 demonstrates the behavior of both Reload Counters.
Figure 20.6-2 Counting Example of the Reload Counters
Note:
The falling edge of the Serial Clock Signal always occurs | (v + 1) / 2 | machine clock cycles after the
rising edge.
001 000 832 831 830 829 828 827
Transmission/
Reload
Count
418 417 416 415 414 413 412 411
Transmission/
Reload
Count
reload count value
Reception Clock
Reception Clock
Содержание MB90390 Series
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Страница 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
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Страница 132: ...104 CHAPTER 5 CLOCKS ...
Страница 152: ...124 CHAPTER 6 CLOCK MODULATOR ...
Страница 210: ...182 CHAPTER 11 TIME BASE TIMER ...
Страница 218: ...190 CHAPTER 12 WATCHDOG TIMER ...
Страница 264: ...236 CHAPTER 14 16 BIT RELOAD TIMER WITH EVENT COUNT FUNCTION ...
Страница 274: ...246 CHAPTER 15 WATCH TIMER ...
Страница 306: ...278 CHAPTER 17 DTP EXTERNAL INTERRUPTS ...
Страница 338: ...310 CHAPTER 18 8 10 BIT A D CONVERTER ...
Страница 364: ...336 CHAPTER 19 UART0 UART1 ...
Страница 398: ...370 CHAPTER 20 UART2 UART3 Figure 20 5 2 ORE Set Timing Receive data RDRF ORE ...
Страница 432: ...404 CHAPTER 20 UART2 UART3 ...
Страница 482: ...454 CHAPTER 22 SERIAL I O ...
Страница 560: ...532 CHAPTER 24 STEPPING MOTOR CONTROLLER ...
Страница 582: ...554 CHAPTER 27 ROM MIRRORING MODULE ...
Страница 632: ...604 CHAPTER 29 EXAMPLES OF SERIAL PROGRAMMING CONNECTION ...
Страница 722: ...694 APPENDIX ...
Страница 723: ...695 INDEX The index follows on the next page This is listed in alphabetic order ...
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