Quick question does the AD9144 also have scratchpad register?
If so, what is it's purpose?
Hmmm, okay understood.
But you did add a very useful functionality to the design, which BTW is available in the ad9680 (scratchpad register is in the datasheet).
The AD9144 does not have a scratchpad register currently. Typically it is used simply to confirm SPI communication is working properly. The user can write any value to the register and it will readback the programmed value unless the part is reset or power cycled. It does not affect the operation of the product.
Agree the datasheet does not speak to any scratchpad register, but in the ad9144 (Non_OS drivers) states there is!
In the driver "0xAD" is written and read back - just as you described.
Can we use this as scratchpad register or is there functionality behind the register?
The code you referenced simply includes some engineering registers that are used during the product development phase. These registers are not released for public use however and we do not recommend writing to them as they are not supported or listed in the official datasheet.
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