3.3.2 Clock Circuitry

A crystal oscillator is assembled on the PL460-EK board to obtain a precise and stable system clock reference:
  • A 24 MHz clock signal, Y1, generated for the PLC block. For more information about VXM7-9043-24M0000000, refer to the VXM7 product webpage.
Figure 3-7. 24 MHz Crystal Oscillator Scheme

Clext = 2x (CXTAL – CPARA – CPCB)

Clext = 2x (4/18 – 0.6/0.7/0.8 – x)

Clext = 2x (18 – 0.7 – 1) = 33 pF

For further information about the crystal oscillator, see the Crystal Selection Guidelines for PL360, ATPL230, ATPL250, SAM4CP16B & SAM4CP16C Application Note.