Samsung S3F80P5X, User Manual

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S3F80P5_UM_ REV1.00 CLOCK AND POWER CIRCUITS
7
CLOCK AND POWER CIRCUITS
OVERVIEW
The clock frequency for the S3F80P5 can be generated by an external crystal or supplied by an external clock
source. The clock frequency for the S3F80P5 can range from 1MHz to 8 MHz. The maximum CPU clock
frequency, as determined by CLKCON register, is 8 MHz. The X
IN
and X
OUT
pins connect the external oscillator
or clock source to the on-chip clock circuit.
Typically, application systems have a resister and two separate capacitors across the power pins in order to
suppress high frequency noise and provide bulk charge storage for the overall system.
SYSTEM CLOCK CIRCUIT
The system clock circuit has the following components:
— External crystal or ceramic resonator oscillation source (or an external clock)
— Oscillator stop and wake-up functions
— Programmable frequency divider for the CPU clock (f
OSC
divided by 1, 2, 8, or 16)
— Clock circuit control register, CLKCON
7-1