Programming the clock generator (Si5356) on the zipper board


#1

Trying to program the clock generator, so I can generate pll clock, tx clock and rx clock.
I have an FPGA connected through the HSMC connector to the zipperboard which as the myriadrf board connected with the LMS6002D on it.

As far as I can see, I am suppose to use the SPI interface (CS_2), which is connected to the zipper MCU, which intern is driving the I2C lines towards the clock generator. Is there anything I need to do to setup the MCU? I am trying to use the SPI interface to enable the clocks, but I see no I2C activity out of the MCU. I do see the data and CS_2 into the MCU beeing driven. I am able to use SPI (CS_0) to program the LMS6002D device.
I have modified the connections on the zipper board by removing R15, and adding R24. Also moved the SPI resistors to the “non-usb option”.

As an alternative, it also looks like I can add an I2C master to my FPGA and drive them directly if I add R74 and R75. However, when I look at the HSMC connection towards the FPGA, it seems like SDA is connected to pin 111, and SCL is connected to pin 113. But pin 111 is a power pin, am I reading this correct?


#2

Been looking at resistor R15 and it doesn’t make any sense to remove it. Is it a typo in the wiki?
Section 3.1.
https://wiki.myriadrf.org/Zipper_Interface_Board_Connections
R15 is not even a 0 ohms resistor, and it is connected to U6 regulator.

I also have a “Zipper and Myriad-RF 1 Development Kit Manual”, which states something different.
It says to remove R2 and add R5. Makes alot more sense, when looking at the schematics and the zipper board. :slightly_smiling: R2 is the output of the clock buffer and R5 is output of the clock synthesizer driving “clk_in”.

Will try to add back R15, and move R1 resistor to R5.


#3

After looking at things some more, I see that I misunderstood what the MCU is for :slightly_smiling:
I can not use it the way I thought. So my only option is to drive the I2C interface from the FPGA.
Which is what I would want anyway.
However, SDA is connected to pin 111, which is a power pin, so I am guessing this is not correct. Anyone know which HSMC pin SDA is connected to?