K60P100M100SF2RM Datasheet, PDF (579/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

25.8.1 OSC Module States
Chapter 25 Oscillator (OSC)
The states of the OSC module are shown in the following figure. The states and their
transitions between each other are described in this section.
OSCCLK
not requested
Off
Oscillator OFF
OSC_CLK_OUT = Static
OSCCLK requested
&&
Select OSC internal clock
OSCCLK requested
&&
Select clock from EXTAL signal
Start-Up
Oscillator ON, not yet stable
OSC_CLK_OUT = Static
External Clock Mode
Oscillator ON
OSC_CLK_OUT = EXTAL
CNT_DONE_4096
Stable
Oscillator ON, Stable
OSC_CLK_OUT = XTL_CLK
Figure 25-7. OSC Module State Diagram
NOTE
XTL_CLK is the clock generated internally from OSC circuits.
25.8.1.1 Off
The OSC enters the Off state when the system does not require OSC clocks. Upon
entering this state, XTL_CLK is static unless OSC is configured to select the clock from
the EXTAL pad by clearing the external reference clock selection bit. For details
regarding the external reference clock source in this MCU, refer to the chip configuration
chapter. The EXTAL and XTAL pins are also decoupled from all other oscillator
circuitry in this state. The OSC module circuitry is configured to draw minimal current.
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
579