MC80F0304/08/16
November 4, 2011 Ver 2.12
115
22.2 Oscillation Fail Processor
The oscillation fail processor (OFP) can change the clock source
from external to internal oscillator when the oscillation fail oc-
cured. This function could be enabled or disabled by the “OFP”
bit of the Device Configuration Area (MASK option for
MC80F0304/0308/0316).
And this function can recover the external clock source when the
external clock is recovered to normal state.
IN4(2)MCLK/CLKXO(XO) Option
The “IN4MCLK(XO)”, “IN2MCLK(XO)” bit of the Device
Configuration Area (MASK option for MC80F0304/0308/0316)
enables the function to operate the device by using the internal os-
cillator clock in ONP block as system clock. There is no need to
connect the x-tal, resonator, RC and R externally. The user only
to connect the X
IN
pin to V
DD
. After selecting the this option, the
period of internal oscillator clock could be checked by X
OUT
out-
putting clock divided the internal oscillator clock by 4.
