231
CHAPTER 14 16-BIT RELOAD TIMER (WITH EVENT COUNT FUNCTION)
14.3
Internal Clock and External Clock Operations of 16-bit
Reload Timer
The machine clock divided by 2
1
, 2
3
, or 2
5
can be selected as the clock sources for
operating the timer from an internal divide clock. The external input pin can be selected
as either a trigger input or gate input by a register setting.
If an external clock is selected, the TIN pin functions as an external event input pin to
count the number of valid edges set in the register.
■
Internal Clock Operation of 16-bit Reload Timer
Writing "1" to both the CNTE and TRG bits in the control register enables and starts counting at one time.
Using the TRG bit as a trigger input is always available when the timer is enabled (CNTE = 1), regardless
of the operation mode.
Figure 14.3-1 shows the activation and operation of 16-bit reload timer counter. A time period T (T:
machine cycle) is required from the counter start trigger being input until the reload register data is loaded
into counter.
Figure 14.3-1 Activation and Operation of 16-bit Reload Timer Counter
T
-1
-1
-1
Count clock
Counter
Data load
CNTE (bit)
TRG (bit)
Reload data
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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