PXS20RM Datasheet, PDF (1148/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Oscillators
Table 35-4. RC_CTL field descriptions
Field
Description
OSCBYP
EOCV
M_OSC
I_OSC
External Crystal Oscillator bypass
This bit specifies whether the oscillator should be bypassed or not. System reset is needed to reset this
bit.
0: Oscillator output is used as root clock.
1: XTALOUT is used as root clock.
End of Count Value
These bits specify the end of count value to be used for comparison by the oscillator stabilization
counter OSCCNT after reset or whenever it is switched on from the off state. This counting period
ensures that external oscillator clock signal is stable before it can be selected by the system. When
oscillator counter reaches the value EOCV[7:0]*512, oscillator available interrupt request is generated.
The reset value of this field depends on the device specification. The OSCCNT counter will be kept
under reset if oscillator bypass mode is selected.
External Crystal oscillator clock interrupt mask
0: External crystal oscillator clock interrupt is masked.
1: External crystal oscillator clock interrupt is enabled.
External crystal oscillator clock interrupt
This bit is set by hardware when OSCCNT counter reaches the count value EOCV[7:0]*512. It is cleared
by software by writing ‘1’.
0: No oscillator clock interrupt occurred.
1: Oscillator clock interrupt pending.
35-4
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor