https://onlinedocs.microchip.com/oxy/GUID-B6A81DBA-6AA5-4E9A-8EF4-B633AF28B555-en-US-17/GUID-0B25AEAA-F5ED-4579-B245-31073F386A8F.html
25.5.2 CLKRCLK
https://onlinedocs.microchip.com/oxy/GUID-AD814995-C874-4FB3-9E6E-CDF76EC617C3-en-US-7/GUID-0B25AEAA-F5ED-4579-B245-31073F386A8F.html
21.5.2 CLKRCLK