I2c 16bit register access

[D Srinivasa Reddy]

Hi Anil,

I have one i2c slave whose registers are to be accessed by 16bit register addresses. data at registers is 8bit. How to access 16bit registers of i2c device. if I write as below it is not working. 

  buf[0]=(0x00FF&regbuf[i].address);  /* first 8bit LSB address [7:0] */
  buf[1]=((0xFF00&regbuf[i].address)>>8);  /*second 8bit, MSB of address [15:8] */
  buf[2]=regbuf[i].value;   /* 8 bit data to write to 16bit address */
 
  if (write(file, buf, 3) != 3) { 

   }

Thanks and Regards

srinivasa

[Abhishek Kumar Trivedi]

Hello

You didn't send slave address, before register address you need to send slave adress.

Regards

Abhishek kumar Trivedi  

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Regards

Abhishek Kumar Trivedi

[D Srinivasa Reddy]

Hi Abhishek, ofcourse without slave address i2c controller won't detect the device, can't probe device ready itself. The question is if the i2c device has >256 registers address space, how those registers can be accessed.Anyway I got solution.

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[Anil Kumar Pugalia]

Typically, 16-bit addressing is the solution. But more than that the device data sheet should tell us as what exactly to send to the device. Anyways, please share the solution you got.

Thanks & Regards
Anil

Passion: http://sysplay.in (Playing with Systems)

D Srinivasa Reddy wrote on 25/10/20 4:53 pm:

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[D Srinivasa Reddy]

Anil sir, forgot to reply. as you have mentioned device data sheet is only the way, somewhere bridge registers are mentioned through which master can access 64KB address space of the device.

Thanks and regards

srinivasa

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