YenYu
Member level 5
Looks like it's kind of hard to implement it on wat u haf show. Because ur MHz is set to a real no. But in VHDL i dont think it is possible to set a real no. Also ur Mhz uses to the extent of .01 , so it might be even harder, only way i could onli set it to is 125000000 for 125MHz and running from 0MHz to 125MHz using (32bits) inputs is even hard...
I've try on sending some inputs to the DATA pins. Looks like it works like this....
DATA<= "01000000000000000000000000000000", --DDS output at 125MHz
"00111101011100001010001111010111" after 100 ns, --DDS output at 120MHz
"00110011001100110011001100110011" after 200 ns, --DDS output at 100MHz
"00101000111101011100001010001111" after 300 ns, --DDS output at 80MHz
"00011110101110000101000111101011" after 450 ns, --DDS output at 60MHz
"00010100011110101110000101000111" after 600 ns, --DDS output at 40MHz
"00001010001111010111000010100011" after 800 ns; --DDS output at 20MHz
The values i get is by using ur equation u haf given me..
So after simulation, i got the desired frequency i wanted, all tallies. But then, there is no dropping of amplitude sign.. The range is from 0MHz,5MHz,25MHz,45MHz,65Mhz,85MHz and 105MHz. So i think it might be the filter problem? wat do u think?
I suspect the problem lies in my Frequency Config setting in the FIR Complier v1.0
I've try on sending some inputs to the DATA pins. Looks like it works like this....
DATA<= "01000000000000000000000000000000", --DDS output at 125MHz
"00111101011100001010001111010111" after 100 ns, --DDS output at 120MHz
"00110011001100110011001100110011" after 200 ns, --DDS output at 100MHz
"00101000111101011100001010001111" after 300 ns, --DDS output at 80MHz
"00011110101110000101000111101011" after 450 ns, --DDS output at 60MHz
"00010100011110101110000101000111" after 600 ns, --DDS output at 40MHz
"00001010001111010111000010100011" after 800 ns; --DDS output at 20MHz
The values i get is by using ur equation u haf given me..
PINC = 2^accumulator_bits * desired_frequency / sample_rate
So after simulation, i got the desired frequency i wanted, all tallies. But then, there is no dropping of amplitude sign.. The range is from 0MHz,5MHz,25MHz,45MHz,65Mhz,85MHz and 105MHz. So i think it might be the filter problem? wat do u think?
I suspect the problem lies in my Frequency Config setting in the FIR Complier v1.0