16-Bit Oscillator System: Primary Oscillator (POSC)

External Clock and Oscillator Modes

The Primary Oscillator (POSC) uses the OSC1 and OSC2 pins. POSC can be configured for an external clock input (EC mode), or an external crystal or resonator (XT or HS modes).

The clock frequencies associated with these modes are device dependent. Please see the specific device data sheet for details.

posc-1.png

Code Example:

The following MPLAB® XC16 compiler code example enables the Primary Oscillator as the default system clock and selects HS oscillator mode (supporting an external crystal) for a PIC24FJ128GA010 MCU:

#include <xc.h>

#pragma config FNOSC PRI        // Enable primary oscillator (XT, HS, EC)
#pragma config POSCMOD HS        // HS oscillator mode selected

int main(void)
{
    ...
}
© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.