Dear Sir/Madam,

How to caculate the multiplier value . Because the multiplier range is from to 8X to 255X, and the 0000=8X , 0001=9X ...1111=255X, and my question is hwo 4 bit could configure 8-255 value. 8 bit seems reasonable.

Could you please clarify above

Thanks.

The multiplication factor is set using the 8 bits in CFR3 which are called Feedback Divider N(7:0). Whatever value is programmed there is multiplied by 2 to get the total multiplier. Note that these bits must be at least 10 decimal (or 00001010) in binary)