Fujitsu F2 MC-8FX Family, Hardware Manual

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CHAPTER 6 CLOCK CONTROLLER
6.1 Overview of Clock Controller
The F
2
MC-8FX family has a built-in clock controller that optimizes its power
consumption. It includes two- system clock product supporting both of the main clock
and subclock and single system clock product supporting only the main clock.
The clock controller enables/disables clock oscillation, enables/disables the supply of
clock signals to the internal circuitry, selects the clock source, and controls the PLL
and frequency divider circuits.
■
Overview of Clock Controller
The clock controller enables/disables clock oscillation, enables/disables clock supply to the internal
circuitry, selects the clock source, and controls the PLL and frequency divider circuits.
The clock controller controls the internal clock according to the clock mode, standby mode settings and the
reset operation. The current clock mode selects the internal operating clock and the standby mode selects
whether to enable or disable clock oscillation and signal supply.
The clock controller selects the optimum power consumption and features depending on the combination of
clock mode and standby mode.
Two- system clock product have three different source clocks: a main clock, which is the main oscillation
clock divided by two, a subclock, which is the sub oscillation clock divided by two and a main PLL clock,
which is the main oscillation clock multiplied by the PLL multiplier.
Single system clock product have two different source clocks: a main clock, which is the main oscillation
clock divided by two; and a main PLL clock, which is the main oscillation clock multiplied by the PLL
multiplier.