Showing results for 
Show  only  | Search instead for 
Did you mean: 
Registered: ‎06-17-2016

DDS Configuration Problem

Hi My Tools: IDE: ISE 14.7 DDS IP CORE Version: 4 I want to make LFM signal, I studied DDS IP core datasheet and I run som LFM simulation that I found on the internet. now I want to make a LFM signal with below parameters: LFM band with 20 kHz (69..99Mhz to 70.01Mhz) in 7.8 ms. I want to set the IP core but I confused. I calculate Phase Increment for 69..99Mhz and 70.01Mhz but the result isn't correct(F_Sysclk=210mhz, Phase Increment With= 29b) I increment "Phase Increment" every 24*(1/F_Sysclk) until 7.8ms. Please guide me what is my mistake I calculate DDS IP Core parameters in Matlab as below: Tou=7.8e-3; F_SysClk=210e6; F0=69.99e6; F1=70.01e6; T_SysClk=1/F_SysClk; Step_Time=21*T_SysClk Step_Rate=Tou/Step_Time; Delta_F=(F1-F0)/Step_Rate; B=round(log2(F_SysClk/Delta_F)); Phase_With=2^B; Frq_Res=F_SysClk/Phase_With; Phase_Increament0=F0*Phase_With/F_SysClk; Phase_Increament1=F1*Phase_With/F_SysClk; Tou/(Phase_Increament1-Phase_Increament0) for i=1:Step_Rate Fout(i)=Frq_Res*Phase_Increament0; Phase_Increament0=Phase_Increament0+1; end; figure plot(Fout) Best Regards
0 Kudos
0 Replies