241
CHAPTER 15 WATCH TIMER
Table 15.2-1 Timer Control Register (Lower)
Bit name
Function
bit7 to
bit5
Reserved
These are reserved bits. Always write "0" to these bits.
bit4,
bit3
Undefined
−
bit2
UPDT: Update bit
The UPDT bit is prepared for modifying the Second/Minute/Hour counter values.
To modify the counter values, write the modified data in the Second/Minute/Hour
registers. Then set the UPDT bit to "1". The register values are loaded to the counter
at the next CO signal from the 22-bit prescaler. The UPDT bit is reset by the hardware
when the counter values are updated. However, if the set operation by software and
the reset operation by hardware occur at the same time, the UPDT bit will not be
reset.
Note:
If this bit is set during "59 second", normal up count operation is executed and this
bit is reset to "0" without reflecting the Second/Minute/Hour register values.
Writing "0" to the UPDT bit has no effect and a read-modify-write (RMW)
instruction results in reading "0".
bit1
OE:
Output enable bit
When the OE bit is set to "1", the WOT external pin serves as the output for the
Watch Timer. Otherwise it can be used as a general purpose I/O or for another
peripheral block.
bit0
ST: Start bit
When the ST bit is set to "1", the Watch Timer loads Second/Minute/Hour values
from the registers and starts its operation. When it is reset to "0", all the counters and
the prescalers are reset to "0" and halts.
Содержание MB90390 Series
Страница 2: ......
Страница 4: ......
Страница 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
Страница 18: ...xiv ...
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 ...
Страница 740: ......