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AD9643 SPI Write Problem

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jason_bill

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Hi,

I want to write to the AD9643 Register through SPI interface by FPGA.
I have developed spi core. Read operation work correctly becuase when i read value of register
it returns the default values as same as is mentioned in the data sheet.

But the write operation not work. for example i want to set the 0x0B to 0X03 such as picture 1 but it returns default value again!
7194214700_1428240994.jpg
 

FvM

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SPI clock phase doesn't seem to be right in the diagram, also the meaning of MISO and MOSi signals isn't clear because AD9643 has a bidirectional SDIO line.
 

jason_bill

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Thanks,
I assigned SDIO as below:
Code:
assign sdio = (spi_dir)? 1'bz : mosi_sig; 
assign miso_sig = (spi_dir)? sdio : 1'b0;
when R/W bit equal '1' spi_dir is asserted by spi core.
 

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when R/W bit equal '1' spi_dir is asserted by spi core
I presume, it's asserted in the data phase only.

More generally speaking, you have a Verilog design operating the interface, of course the timing diagram doesn't give the design details. Did you understand about the wrong clock phase that I mentioned?
 

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