AN 661: Implementing Fractional PLL Reconfiguration with Altera PLL and Altera PLL Reconfig IP Cores

ID 683640
Date 10/14/2019
Public
Document Table of Contents

1.2.1.1. Waveform Example for Dynamic Phase Shift with Altera PLL IP Core

Figure 5. Waveform Example for Dynamic Phase Shift with Altera PLL IP Core

The operation of the waveform example is as follows:

  1. Set the cntsel port to logical counter C1 and the updn port to positive phase shift direction.
  2. Assert the phase_en port to begin the first phase shift operation on logical counter C1.
  3. Deassert the phase_en port after phase_done goes low.
  4. Assert the phase_en port again to begin the second phase shift operation.
  5. Deassert the phase_en port after phase_done goes low.