MC9S08AC16_08 Datasheet, PDF (22/344 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

Chapter 1 Introduction
Table 1-2 lists the functional versions of the on-chip modules.
Table 1-2. Versions of On-Chip Modules
Module
Analog-to-Digital Converter
Internal Clock Generator
Inter-Integrated Circuit
Keyboard Interrupt
Serial Communications Interface
Serial Peripheral Interface
Timer Pulse-Width Modulator
Central Processing Unit
(ADC)
(ICG)
(IIC)
(KBI)
(SCI)
(SPI)
(TPM)
(CPU)
Version
1
4
2
1
4
3
3
2
1.3 System Clock Distribution
ICGERCLK
FFE
SYSTEM
CONTROL
LOGIC
TPMCLK
RTI
TPM1
TPM2
IIC1
SCI1
SCI2
SPI1
2
ICG
XCLK**
COP
1 kHz
ICGOUT
2
ICGLCLK*
BUSCLK
CPU
BDC
TPM3***
ADC1
RAM
FLASH
* ICGLCLK is the alternate BDC clock source for the MC9S08AC16 Series.
** XCLK is the fixed-frequency clock.
*** TPM3 is not available on MC9S08AWxxA devices.
ADC has min and max
frequency requirements.
See the Electricals appendix
and the ADC chapter.
FLASH has frequency
requirements for program
and erase operation.
See the Electricals
appendix.
Figure 1-2. System Clock Distribution Diagram
Some of the modules inside the MCU have clock source choices. Figure 1-2 shows a simplified clock
connection diagram. The ICG supplies the clock sources:
• 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
sub-module
MC9S08AC16 Series Data Sheet, Rev. 6
22
Freescale Semiconductor