mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 474

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Functional Description
21.8.1.1 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.
474
XTL_CLK is the clock generated internally from OSC circuits.
OSCCLK
not requested
Oscillator ON, Stable
OSC_CLK_OUT = XTL_CLK
Oscillator ON, not yet stable
OSC_CLK_OUT = Static
Select OSC internal clock
OSCCLK requested
Start-Up
Stable
Figure 21-10. OSC Module State Diagram
MCF51JF128 Reference Manual, Rev. 2, 03/2011
&&
CNT_DONE_4096
Oscillator OFF
OSC_CLK_OUT = Static
Preliminary
NOTE
Off
Select clock from EXTAL signal
External Clock Mode
OSCCLK requested
Oscillator ON
OSC_CLK_OUT = EXTAL
&&
Freescale Semiconductor, Inc.