17.3.5 RFPLL Wrapper

The output of RFPLL wrapper is used as a system clock or REFO clock source. Selection of the system clock source is performed with the OSCCON.NOSC[3:0] register field.

The RFPLL wrapper generates two clocks:

  • SPLL_CLK1 (PGM MHz)
    • Clock frequencies = 64 MHz/(1-255) frequency choices
    • Clock ready indication
  • SPLL_CLK2 (PGM MHz)
    • Clock frequencies = 64 MHz/(1-15) and optional clock disable option
    • Clock ready indication

Clocks are produced only when the consumer generates a request; CRU is the consumer for SPLL_CLK1 (SPLL_CLK1 is chosen through OSCCON.NOSC[3:0]) and ADC charge pump is the consumer for SPLL_CLK2, (SPLLCON.SPLL_BYP[1:0]). Along with the clocks, individual clock ready is also generated, which indicates that clocks are ready for consumption.