AD9858 DDS sweep mode, help please...
时间：04-10
整理：3721RD
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I desperately need help to get AD9858 in sweep mode under the control.
I'm interfacing AD9858 via PC parallel port (just a proof of concept) and before I migrate my code to microcontroller I need to solve last problem.
These features currently work fine for me:
- Single tone up to cca 440 MHz
- Profile switching
- Frequency sweep
When I set up "Freq. Sweep Enable" control bit, the DDS starts sweeping in whole bandwidth.
This feature doesn't work for me:
- Frequency sweeping in defined (limited) bandwidth, let's say between 100 and 200 MHz, delta freq. 2 MHz, delta freq. ramp rate 0.5 ms.
How to say the DDS to finish sweep period when the end of my bandwidth is reached?
I know I have to calculate sweep period time. But what to do next? There is a sentence in datasheet saying to write 0 to DFRRW register but this doesn't work for me.
Can anybody help, please?
I'm interfacing AD9858 via PC parallel port (just a proof of concept) and before I migrate my code to microcontroller I need to solve last problem.
These features currently work fine for me:
- Single tone up to cca 440 MHz
- Profile switching
- Frequency sweep
When I set up "Freq. Sweep Enable" control bit, the DDS starts sweeping in whole bandwidth.
This feature doesn't work for me:
- Frequency sweeping in defined (limited) bandwidth, let's say between 100 and 200 MHz, delta freq. 2 MHz, delta freq. ramp rate 0.5 ms.
How to say the DDS to finish sweep period when the end of my bandwidth is reached?
I know I have to calculate sweep period time. But what to do next? There is a sentence in datasheet saying to write 0 to DFRRW register but this doesn't work for me.
Can anybody help, please?