Hi
I connected a Si3215 to a AtXmega32 directly without any buffer like as 74LV244.
At start of program I read register 0 , 1 , 2 and ... but there is a problem with read of every register by SPI (SPI in mode 3 or 2). All register that is read, is 0 or 255 and not seems to be correct. In your opinion the problem is in my hardware like as buffer between si3215 and micro controller or there is a software problem like as initialize the Si3215?

Thanks in advance.

 

datasheet shows that the registers can be written to.
you, the user, can fill the registers with whatever you want.

 

datasheet shows that the registers can be written to.
you, the user, can fill the registers with whatever you want.

Thanks for your response,
For example I write 0x2 in register n , but when I read same register it returns 0

 

Registers for a peripheral device do not always work like memory. It is quite possible to read different values than you write. Without a schematic it is hard to know what your problem might be.

Can you give us a link to a datasheet for this obsolete part?

 

Registers for a peripheral device do not always work like memory. It is quite possible to read different values than you write. Without a schematic it is hard to know what your problem might be.

Can you give us a link to a datasheet for this obsolete part?

I attached its schematic. According to si3215 datasheet , reset setting of register 0 is 00XXXXXX and register 1 is 10001000 . But sometimes after reset of si3215, it returns 10001000 for all registers (reg 0,1,2,3, and...)!!! and sometimes after reset of si3215, it returns 00000000 for all registers!!!
But I expect its registers value be like as its datasheet value!

 

@Papabravo below is a link to the datasheet:

www.mouser.com/ds/2/368/Si3215-276819.pdf

 

Oh my GOD!
I found the problem! I didn't feed clock pulse to PCLK pin.

Regarding to Si3215 datasheet page 42:

Clock Generation
The ProSLIC will generate the necessary internal clock frequencies from the PCLK input. PCLK must be synchronous to the 8 kHz FSYNC clock and run at one of the following rates: 256 kHz, 512 kHz, 768 kHz, 1.024 MHz, 1.536 MHz, 2.048 MHz, 4.096 MHz, or 8.192 MHz.