The datasheet is not clear how to configure the HMC1044 and it's not very easy as this chip is write only.
Description of SPI link with 9 bits data, 4 bits reg_addr and 3 bits chip_addr :
Next page, description of unique register :
I think I have to write directly the 16bits reg value but can you confirm ?
Apologies as there is some confusion between the total bits clocked in and the length of the data bits.
Yes, each SPI transaction is 16 bits long, 9 of which are data, 4 are register address and 3 are…
Yes, each SPI transaction is 16 bits long, 9 of which are data, 4 are register address and 3 are Chip address.
The data bits only take up the four LSBs of the 9-bit data word, so to write to the autotune register, you would write:
0b[0 0 0 0 0 d3 d2 d1 d0 0 0 0 1 1 1 0]
where d0, d1, d2 and d3 are the four relevant data bits whose value ranges from 0b0000 to 0b1111
Hope this helps!
Now it's clear, thanks.