4.17.9 Programmable Clock Output Controller

The PMC controls eight signals to be output on the external pins PCKx. Each signal can be independently programmed via the Programmable Clock registers (PMC_PCKx).

PCKx can be independently selected between MD_SLCK, TD_SLCK, MAINCK, MCK0 and any PLLCK except CPUPLLCK, DDRPLLCK and LVDSPLLCK by configuring PMC_PCKx.CSS. Each output signal can also be divided by 1 to 256 by configuring PMC_PCKx.PRES.

Each output signal can be enabled and disabled by writing a ‘1’ to the corresponding bits PMC_SCER.PCKx and PMC_SCDR.PCKx, respectively. The status of the active programmable output clocks is given in PMC_SCSR.PCKx.

The status flag PMC_SR.PCKRDYx indicates that the clock configured through the PMC_PCKx register is correctly established.

As the Programmable Clock Controller does not manage with glitch prevention when switching clocks, it is strongly recommended to disable PCKx before any configuration change and to re-enable it once the change is performed.