Fujitsu FR81S User Manual
CHAPTER 5: CLOCK
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK
FUJITSU SEMICONDUCTOR CONFIDENTIAL
80
5.6.2. Procedure of Gear Down
The procedure of gear down is shown.
1. When the clock gear start (CCCGRCR0:GRSTR) is set to "1" and the rising is detected, the clock gear
status flag (CCCGRCR0:GRSTS[1:0]) transits to "10" → "11" (gear down start).
2. The gear down is executed according to the clock gear step selection and the repeat number selection.
The step number is the smaller and the repeat number is the larger that the operation changes the more
gradually.
3. When the clock reaches the minimum step, the clock gear status flag (CCCGRCR0:GRSTS[1:0])
transits to "11" → "00" (the end of gear down, the gear stops). After this, the clock of the start step set
for the clock gear start step selection is output.
4. After the gear stops, the clock gear start (CCCGRCR0:GRSTR) is cleared to "0" by hardware.
MB91520 Series
MN705-00010-1v0-E
241