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AD9914 Parallel Mode

Question asked by BTS on May 3, 2013
Latest reply on May 27, 2013 by BTS

Hi I'm Using the AD9914 eval board and i want to use it in direct mode (and for setting up in parallel prgramming mode)

the first question is about the eval board. in the schematics there is a part where it says: Remove for parallel use (R105-R109)

do i really have to remove the Resistors if i want to use  the board in parallel mode? and which fuktion do i lose if i do so?

Are there any other parts i need to remove?


afterwards i come to the programming: Do i need to send a logic low if i want a pin to be low or is it enough to leave it open

(for example i dont need the MPI005 input; do i have to set it to ground with a jumper or can i leave it open)


3. I want wo use the parallel programming mode in 8 bit, therefore i set the funktion pins to 0000 (here again the MSB is isnt needed any futher so i want to set it low permanantly). Afterwards i  set the parallel control bits [2:0] to 000 (last 0 for the 8 bit mode, second for read and third for write)

and now my question is do i need to read? when programming i thought i just need to write. and now a logic low signal means the system is writing /reading to the DDS. then i set up the system and afterwards i send an I/O Update signal for transfering to the DDS. do i have to send the information (the programming) after each change o can i first change all settings and just send one update at the very end? also do i need an update for a master reset? means if i do a master reset at the beginning of the parallel programming, to i need a update signal to send the master reset signal to the DDS?

and one (hopefully) last question: i am programming in parallel port...and in CFR2 there is an option enable parallel dataport. do i need to activate it when i want to use the DDS in direct mode? and shouldn't it be activated before i use the parallel programming? but how can i do it, before programming?


thanks and best regards