Fujitsu FR81S User Manual
CHAPTER 5: CLOCK
1. Overview
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK
FUJITSU SEMICONDUCTOR CONFIDENTIAL
3
1. Overview
This section explains the overview of the clock.
The built-in oscillation circuit generates a dual clock product, which generates individual clock systems on
the chip. This product also implements the CR oscillation circuit that can be used as sub-clock.
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External pins for the built-in oscillation circuit :
Main clock
: Connects to the crystal resonator
Sub clock
: Connects to the crystal resonator
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Generation of source clocks : Selects from the clocks which are multiplied by PLL/SSCG of main clock
(MCLK) or divided by 2 of main clock, or sub clock (SBCLK).
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Division of source clock : Divides the source clock and generates operating clocks for supplying to each
unit.
MB91520 Series
MN705-00010-1v0-E
164