I am using a microcontroller to program ADF4351's 6 registers on this board using SPI via P2 header pins. See layout of the P2 header pins below:
Here is my wirings:
- Pins P2-1 and P2-2 are the LE pin (active low)
- Pins P2-3 and P2-7 are data and clock pins
- Pins P2-9 and P2-10 are connected to GND pin of the microcontroller.
- Pins P2-11 and P2-12 are connected to 3v3 source of the microcontroller. (not sure what this pin is for)
Is it correct ?
What do pins P2-11 and P2-12 do ?
I am asking so because I have trouble reading back MUX_OUT pins using a multimeter.
Most of the time, it didn't work. I was rarely able to read back some changes on the MUX_OUT pins.
I tried to set LD pins through register 5 on the ADF4351 to high, to turn on LED DS1 and DS2. But It was successful only a couple of times.
I am not sure what's the problem. Any suggestion ?