bits:1, freq:8000000, maxDuty:2
bits:2, freq:4000000, maxDuty:4
bits:3, freq:2000000, maxDuty:8
bits:4, freq:1000000, maxDuty:16
bits:5, freq:500000, maxDuty:32
bits:6, freq:250000, maxDuty:64
bits:7, freq:125000, maxDuty:128
bits:8, freq:62500, maxDuty:256
bits:9, freq:31250, maxDuty:512
bits:10, freq:15625, maxDuty:1024
bits:11, freq:7812, maxDuty:2048
bits:12, freq:3906, maxDuty:4096
bits:13, freq:1953, maxDuty:8192
bits:14, freq:976, maxDuty:16393
bits:15, freq:488, maxDuty:32786
bits:16, freq:244, maxDuty:65535