MC9S08GB60 Datasheet, PDF (21/290 Pages) Motorola, Inc – Microcontrollers

Table 1-2 lists the functional versions of the on-chip modules.
Table 1-2. Block Versions
Module
Analog-to-Digital Converter (ATD)
Internal Clock Generator (ICG)
Inter-Integrated Circuit (IIC)
Keyboard Interrupt (KBI)
Serial Communications Interface (SCI)
Serial Peripheral Interface (SPI)
Timer Pulse-Width Modulator (TPM)
Central Processing Unit (CPU)
Version
3
2
1
1
1
3
1
2
1.4 System Clock Distribution
SYSTEM
CONTROL
LOGIC
ICGERCLK
RTI
FFE
TPM1
TPM2
IIC1
SCI1
÷2
ICG
FIXED FREQ CLOCK (XCLK)
System Clock Distribution
SCI2
SPI1
ICGOUT
÷2
ICGLCLK*
BUSCLK
CPU
BDC
ATD1
RAM
FLASH
* ICGLCLK is the alternate BDC clock source for the MC9S08GB/GT.
ATD has min and max
frequency requirements.
See Chapter 1, “Introduction”
and Appendix A, “Electrical
Characteristics.
Figure 1-3. System Clock Distribution Diagram
FLASH has frequency
requirements for program
and erase operation.
See Appendix A, “Electrical
Characteristics.
Some of the modules inside the MCU have clock source choices. Figure 1-3 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
Control bits inside the ICG determine which source is connected.
MC9S08GB/GT Data Sheet, Rev. 2.3
Freescale Semiconductor
21