PIC16F753 Datasheet, PDF (39/238 Pages) Microchip Technology – 14/16-Pin, Flash-Based 8-Bit CMOS Microcontrollers

PIC16F753/HV753
4.3 System Clock Output
The CLKOUT pin is available for general purpose I/O or
system clock output. The CLKOUTEN bit of the
Configuration Word controls the function of the
CLKOUT pin.
When the CLKOUTEN bit is cleared, the CLKOUT pin
is driven by the selected internal oscillator frequency
divided by 4. The corresponding I/O pin always reads
‘0’ in this configuration.
The CLKOUT signal may be used to provide a clock for
external circuitry, synchronization, calibration, test or
other application requirements.
When the CLKOUTEN bit is set, the system clock out
function is disabled and the CLKOUT pin is available for
general purpose I/O.
4.4 Oscillator Delay upon Wake-Up,
Power-Up, and Base Frequency
Change
In applications where the OSCTUNE register is used to
shift the HFINTOSC frequency, the application should
not expect the frequency to stabilize immediately. In
this case, the frequency may shift gradually toward the
new value. The time for this frequency shift is less than
eight cycles of the base frequency.
A short delay is invoked upon power-up and when
waking from sleep to allow the memory bias circuitry to
stabilize. Table 4-1 shows examples where the oscillator
delay is invoked.
TABLE 4-1:
Switch From
Sleep/POR
Sleep/POR
OSCILLATOR DELAY EXAMPLES
Switch To
Frequency
INTOSC
EC
31 kHz to 8 MHz
DC – 20 MHz
Oscillator Delay
10 s internal delay to allow memory
bias to stabilize.
 2013 Microchip Technology Inc.
Preliminary
DS40001709A-page 39