mc9s08gt16a Freescale Semiconductor, Inc, mc9s08gt16a Datasheet - Page 22

• Manufacturer Part Number: mc9s08gt16a
• Description: Hcs08 Microcontrollers 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Device Overview
Some of the modules inside the MCU have clock source choices.
connection diagram. The ICG supplies the clock sources:
Control bits inside the ICG determine which source is connected.
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ICGOUT is an output of the ICG module. It is one of the following:
— The external crystal oscillator
— An external clock source
— The output of the digitally-controlled oscillator (DCO) in the frequency-locked loop
FFE is a control signal generated inside the ICG. If the frequency of ICGOUT > 4 × the frequency
of ICGERCLK, this signal is a logic 1 and the fixed-frequency clock will be the ICGERCLK.
Otherwise the fixed-frequency clock will be BUSCLK.
ICGLCLK — Development tools can select this internal self-clocked source (~ 8 MHz) to speed
up BDC communications in systems where the bus clock is slow.
ICGERCLK — External reference clock can be selected as the real-time interrupt clock source.
sub-module
MC9S08GT16A/GT8A Data Sheet, Rev. 1
Figure 1-2
shows a simplified clock
Freescale Semiconductor