Post Go back to editing

HMC1044 SPI configuration

Hi,

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 ?

Thanks,
Stéphane

Parents
  • 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 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!

Reply
  • 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 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!

Children