Fujitsu FR81S User Manual
CHAPTER 24: 16-BIT FREE-RUN TIMER
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : 16-BIT FREE-RUN TIMER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
15
Notes:
The 16-bit free-run timer will not be initialized even when the clear bit (SCLR: bit20) of the timer state
control register (TCCS) is set to 1 while the 16-bit free-run timer is inactive (STOP: bit22=1 of timer state
control register (TCCS)).
When accessing the timer data register, use a half-word or word access instruction.
If a counter value is written during the up/down counter mode (MODE:bit21=1 of timer state control register
(TCCS)), an unintended counting may be performed.
To write a counter value in the up/down counter mode (MODE:bit21=1 of timer state control register
(TCCS)), perform the following steps.
1. Stop the 16-bit free-run timer counter. (Writing 1 in STOP:bit21 of timer state control register (TCCS))
2. Set a counter value for the timer data register.
3. Perform software clear. (Writing 1 in SCLR:bit20 of timer state control register (TCCS))
4. Start the 16-bit free-run timer counter.
MB91520 Series
MN705-00010-1v0-E
922