I am trying to use TX data pulse to trigger the PLL to generate ramp. As per the design of my application , I need to trigger each and every chirp(ramp) and also change the frequency when needed.
It would of great help if some one can answer my doubts:
1. The INITIALIZATION SEQUENCE register loading method given in the data sheet tells that the sequence after powering up the device is r7-r6(STEP SEL = 0)-r6(STEP SEL = 1)-r5(DEV SEL = 0)-r5(DEV SEL = 1)-r4(DEV SEL = 0)-r4(DEV SEL = 1)-r3-r2-r1-r0. But in my application i am directly giving the ramping values to PLL in sequence r7-r6-r5-r4-r3-r2-r1-r0 and its locking successfully. And for change in frequency i am loading all the 8 registers in sequence r7-r6-r5-r4-r3-r2-r1-r0. Is the correct way to change the frequency given my ramp configuration is same for all frequencies and the changing parameters i found is R2 and R0 register.
NOTE: all the questions asked below are using the TX data pulse as trigger for generation of the ramp. Also I have been able to lock the PLL using TX ramp clk in CLK DIV mode.
2. So initially i will load all the 8 register values (in the order R7 - R0)based on the output desired by me. Then the PLL awaits for TX pulse to generate a chirp(ramp). So my doubt is for the next ramp which will be of the same frequency do i need to load any registers before TX data or i just need to toggle TX data when n where i need a chirp.
3. And does each TX data pulse trigger only one chirp ( sawtooth ramp waveform).
4. Now to change frequency is it necessary to load all the 8 register again or does register R0 and R2 sufficient to change the frequency given the type of ramp I need is same.
Thanks and Regards,