Information

 2004 Microchip Technology Inc. DS80177E-page 3
PIC16F7X7
3. Module: Internal RC Oscillator
When any one of the seven INTOSC frequencies
is enabled by the following conditions, it is possible
for the oscillator to overshoot the selected
frequency:
1. A clock switch from INTRC (31 kHz) to an
INTOSC (125 kHz-8 MHz) frequency via the
IRCF bits (OSCCON register).
2. Exit from Sleep mode with the IRCF bits
already configured for an INTOSC frequency.
3. Executing a clock source switch via the SCS
bits (OSCCON register) to the internal RC
oscillator with the IRCF bits already configured
for an INTOSC frequency.
If the selected frequency is 8 MHz, then the
Voltage versus Frequency specification of the
device may be violated.
Work around
When it is required for the application to run at
8 MHz, it is recommended that the application
does not start executing code at 8 MHz until the
60 ms firmware delay (see issue 2) has
completed. During the 60 ms settling period, the
application can execute code up to 4 MHz. Upon
completion of the 60 ms firmware delay, the 8 MHz
can be selected via the IRCF bits.
Date Codes that pertain to this issue:
All date codes.