I am trying to read register F1 to prove SPI communication works and then writing to Register 1F to invert the polarity on OUT0. I'm using Arduino to do this. This is my process following Document No: SNAU204C and SNLS545D
Arduino is master, LMH1297 is slave.
1. Since we are in the shared page, no need to change the page on startup.
2. Write 0xF1FF on MOSI while CS is pulled low to the LMH1297.
3. Toggle CS to initiate the MISO transfer.
4. Write 0xFFFF to MOSI and read MISO.
5. Pull CS high to stop SPI transfer
6. Pull CS low and write 0xFF04 to change the Register page to the CTLE/CDR Register
7. Write 0x1F80 to flip the polarity
Here is the problem:
At step 4 I am expecting the MISO line to read 0xF16B, where 6B is the Device ID. According to SNAU204C, the LMH1297 prgramming guide, this is the device ID for the LMH1297. However, I am getting back 0xFFFF. I have verified my connections already and I am uncertain if I am initiating the data transfer incorrectly.
What about my process outlined above is incorrect?
