mc9s12vr48 Freescale Semiconductor, Inc, mc9s12vr48 Datasheet - Page 166

• Manufacturer Part Number: mc9s12vr48
• Description: S12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Clock, Reset and Power Management (S12CPMU_UHV)
4.4.5
4.4.5.1
An example of how to use the oscillator as Bus Clock is shown in
166
EXTAL
UPOSC
OSCCLK
PLLSEL
Core
Clock
OSCE
External Oscillator
Enabling the External Oscillator
enable external oscillator by writing OSCE bit to one.
based on PLL Clock
crystal/resonator starts oscillating
Figure 4-36. Enabling the external oscillator
MC9S12VR Family Reference Manual,
Preliminary - Subject to Change Without Notice
select OSCCLK as Core/Bus Clock by writing PLLSEL to zero
UPOSC flag is set upon successful start of oscillation
based on OSCCLK
Figure
Rev. 2.2
4-36.
Freescale Semiconductor