MC9S08QD4 Datasheet, PDF (20/202 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 1 Device Overview
Table 1-2. Versions of On-Chip Modules
Module
Analog-to-Digital Converter
Central Processing Unit
Internal Clock Source
Keyboard Interrupt
Timer Pulse-Width Modulator
(ADC)
(CPU)
(ICS)
(KBI)
(TPM)
Version
1
2
1
2
2
1.3 System Clock Distribution
Figure 1-2 shows a simplified clock connection diagram. Some modules in the MCU have selectable clock
inputs as shown. The clock inputs to the modules indicate the clock(s) that are used to drive the module
function. All memory mapped registers associated with the modules are clocked with BUSCLK.
SYSTEM CONTROL LOGIC
TCLK1
TCLK2
ICSIRCLK
ICSFFCLK
RTI
TPM1
COP
FIXED FREQ CLOCK (XCLK)
÷2
TPM2
ICS
ICSOUT
÷2
BUSCLK
CPU
ICSLCLK¹
BDC
ADC²
1 _{ICSLCLK is the alternate BDC clock source for the MC9S08QD4 series.}
2 _{ADC has min. and max frequency requirements. See ADC chapter and Appendix A, “Electrical Characteristics.”}
3 _{Flash has frequency requirements for program and erase operation.See Appendix A, “Electrical Characteristics.”}
Figure 1-2. System Clock Distribution Diagram
FLASH³
MC9S08QD4 Series MCU Data Sheet, Rev. 3
20
Freescale Semiconductor