17.3.2.1 Fast RC Oscillator (FRC)

The on-chip 8 MHz Fast RC Oscillator (FRC) is a fast internal RC oscillator with precise frequency. The FRC oscillator is accurately provides the clock frequency, which is necessary to maintain the baud rate tolerance for serial data transmissions. Power-on Reset (POR) sets OSCCON.NOSC[3:0] = 0000; hence, the device starts with FRC when powered up.

The oscillator module provides a 6-bit wide user tuning adjustment using the OSCTUN.TUN[5:0] bits.