Actually as per my experience with it a software programmable Dual Speed Oscillator mode is provided when the PIC16F62X is configured in either ER or INTRC Oscillator modes. This feature allows users to dynamically toggle the oscillator speed between 4 MHz and 37 kHz. In ER mode, the 4 MHz setting will vary depending on the value of the external
resistor.
And in ER mode, the 37 kHz operation is fixed and does not vary with resistor value. Applications that require low current power savings, but cannot tolerate
putting the part into SLEEP, may use this mode.