26.1 NCO Operation
The NCO operates by repeatedly adding a fixed value to an accumulator. Additions occur at the input clock rate. The accumulator will overflow with a carry periodically, which is the raw NCO output (NCO_overflow). This effectively reduces the input clock by the ratio of the addition value to the maximum accumulator value. Refer to Equation 26-1 for details.
The NCO output can be further modified by stretching the pulse or toggling a flip-flop. The modified NCO output is then distributed internally to other peripherals and can optionally be output to a pin. The accumulator overflow also generates an interrupt (NCO_interrupt). The NCO period changes in discrete steps to create an average frequency.