DS110DF111: DS110DF111 application question

Hi, my inputs below.

1. How to look at the result of eye monitor? Through I2C? 

• That's correct. See procedure below
  

• The application situation is NXP MCU--XFI<-->Retimer<-->SFI--SFP+. Is it OK?
  • Yes. The TI retimer supports both XFI and SFI interfaces
• When DS110DF111 connect with SFP+, there is still coupling capacitor inside SFP module, will the IC need to add coupling capacitor again? The design guide of this IC have added the capacitor. 
  • When the retimer is interfaced to SFP+ module no additional external AC coupling caps are needed, as the SFP+ module already has the caps
  • When the retimer is interfaced to chips with no integrated AC coupling caps then it is required to implement the external AC coupling caps on the system board

Plotting an Eye Diagram

The Eye Opening Monitor is capable of plotting an equalized, but non-retimed eye to represent the quality of signal that is going into the CDR block. This feature is useful for diagnosing gross signal integrity errors. The eye plot generated by the EOM cannot be used to extrapolate performance to bit error rates beyond 1e^-7.

The EOM generates the eye plot according to a 64 x 64 matrix. Each grid space in the matrix consists of a 16-bit word that represents the number of times the incoming data stream touches that particular phase and voltage level. The EOM under-samples the incoming data stream by recording the total hit count for each combination of phase and voltage, one grid space at a time.

To configure the EOM to plot the eye diagram, sometimes called fast eye capture, use the following registers.

• Step	Register[bits]	Value	Description
  1	0x3E[7]	0	Disable lock EOM lock monitoring
  2	0x2C[6] 0x11[7:6]	0 2’b xx	Set the desired EOM vertical range as 2’b xx
  3	0x11[5]	0	Power on the EOM
  4	0x24[7]	1	Enable fast EOM
  5	0x24[0] 0x25 0x26	1	When 24[0] is 1 begin read out of the 64 x 64 array, discard first 4 bytes This bit is self-clearing.
  6	0x24[0] 0x25 0x26	1	Continue reading information until the 64 x 64 array is complete.
  7	0x3E[7] 0x2C[6] 0x11[5] 0x24[7]	1 1 1 0	Return the EOM to its original state. Undo steps 1-4

   

  The data recorded from the Eye Opening Monitor (EOM) begins at (X, Y) position (0, 0) and proceeds to position (0, 63). Next, the Y-value is reset to 0 and the X-value is incremented. This process is repeated until the entire 64 x 64 matrix is read out.
  

Is there a tool installed on the PC to display the eye chart ? Thanks

Hi
How much loss can be supported on DS110DF111 XFI/SFI signal of input channels ？
How much loss can be supported on DS110DF111 XFI/SFI signal of output channels ？

songlin ren
thanks

Hi,

The DS110DF111 indeed supports this application case. There is no KR or SFI specific settings that would need to be applied to the retimer. The user would simply need to the set the retimer for 10.3125Gbps CDR rate. Additionally, I would recommend to use adapt mode 2 (i.e. DFE enabled.)

Regards,

Rodrigo Natal

HSSC Applications Engineer