AnsweredAssumed Answered

HMC7044 SPI Not working

Question asked by vish1ram on Apr 6, 2017
Latest reply on Nov 2, 2017 by kpeker


We made customised board based on HMC7044 Chip taking reference from eval board. We would like to configure the HMC7044 according to our requirements by using GUI. At first we would like to check SPI is working or not, for this we did a  simple check as mentioned in the following link.

HMC7044 configuration problem  


By writing to 0x0050 register, we can make sure that SPI internal block is working fine. unfortunately But our board fails on this configuration also.


We are writing 0x83 to 0x0050 register, so that it will give logic 0 on GPIO1 pin. But it is in default state as logic1.

Please look into the following scope image.Writing 0x83 on Registe 0x0050  

Color: Blue-CSB

         : Red -Clock-100Khz

         :Green- SDIO

Please let me know any configuration that we are missing?

I check all the Power rails of HMC7044 using scope, all are stable(3.295v).


After this step we tried to read the addresses 0x03 and 0x04. Ideally it should give default values mentioned in the datasheet. But it is giving 0xFF always.

Please look into the Scope images.



  Color: Blue-ChipSelct and Red-SDIO.


We have used pull down resistor(27k) to ground on Reset Line, So that it will be out of reset always. We are suspecting device is in reset.


Please let us know is there any  method to know that HMC7044 is not in Reset? 


Please help us to resolve the SPI communication issues.


Thanks & Regards

Rama Krishna