Hi
In the past I've tried to control the AD9959's output amplitude during a linear frequency sweep (see my previous question: https://ez.analog.com/dds/f/q-a/564852/ad9959-constant-amplitude-multiplier )
I never got that to work so I gave up. But now I need it again.
Selecting "Manual mode" via ACR[12:11] did not want to work for me so I guess I'll try automatic mode.
The datasheet section "OUTUT AMPLITUDE CONTROL MODE" states that pins SDIO_1/SDIO_2/SDIO_3 are used for RU/RD operation during linear sweep. I have two questions:
1.
Can you use these pins for RU/RD operation even while the SPI is configured for 4-wire mode? If so I guess you can do either a SPI access or an RU/RD operation but not both...??
2.
Is it possible to ramp up all channels' amplitude at the same time? If I understand Table 23 correctly that does not seem to be the case.
Another question:
3.
it seems that both the linear frequency sweep and the Amplitude RU/RD operation uses the LSRR register. So how can you do a RU/RD operation during a linear frequency sweep if they both use the same register?
Regards
