ZHCSCX2E January 2014 – October 2017 LM15851
PRODUCTION DATA.
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
NCO_RDIV | |||||||
R/W-0x00h | |||||||
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
NCO_RDIV | |||||||
R/W-0x00h |
Bit | Field | Type | Reset | Description |
---|---|---|---|---|
15-0 | NCO_RDIV | R/W | 0x0000h | Sometimes the 32-bit NCO frequency word does not provide the desired frequency step size and can only approximate the desired frequency. This results in a frequency error. Use this register to eliminate the frequency error. Use this equation to compute the proper value to program: Equation 10. NCO_RDIV = ƒS / ƒ(STEP) / 128
where
For example, if ƒS= 3072 MHz, and ƒ(STEP) = 10 KHz then: Equation 11. NCO_RDIV = 3072 MHz / 10 KHz / 128 = 2400
Any combination of ƒS and ƒ(STEP) that results in a fractional value for NCO_RDIV is not supported. Values of NCO_RDIV larger than 8192 can degrade the NCO’s SFDR performance and are not recommended. This register is used for all configuration presets. |