[ibis-macro] Re: question on tap parameters in AMI

  • From: Ambrish Varma <ambrishv@xxxxxxxxxxx>
  • To: "ibis-macro@xxxxxxxxxxxxx" <ibis-macro@xxxxxxxxxxxxx>
  • Date: Thu, 11 Feb 2010 10:06:25 -0800

Hi Fangyi,
The parameters are for the model's consumption. The EDA tool does not have to 
know which group is for FFE and which for DFE.
Thanks,
Ambrish.

________________________________
From: fangyi_rao@xxxxxxxxxxx [mailto:fangyi_rao@xxxxxxxxxxx]
Sent: Thursday, February 11, 2010 12:47 PM
To: Ambrish Varma; ibis-macro@xxxxxxxxxxxxx
Subject: RE: [ibis-macro] Re: question on tap parameters in AMI

Hi, Ambrish;

Thanks for the clarification. In your example a EDA tool will find two groups 
of tap parameter, RX_FFE_Taps and RX_DFE_Taps in the .ami file based on the 
parameter type. How does the tool know which group is for FFE and which is for 
DFE? Note that model specific parameter names can be arbitrary.

Fangyi

From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Ambrish Varma
Sent: Wednesday, February 10, 2010 7:57 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: question on tap parameters in AMI

Hi Fangyi,
You can give any name to the parameters themselves. For ex,
The model_specific section of the RX model with a 5 tap FFE and 3 tap DFE can 
look like:
(Model_Specific
(RX_FFE_Taps
  (-2 (Usage Inout)(Type Tap) (Format Range 0.1 -0.1 0.2)(Default 0.1)
     (Description "Second Precursor Tap"))
  (-1 (Usage Inout)(Type Tap) (Format Range 0.2 -0.4 0.4)(Default 0.2)
     (Description "First Precursor Tap"))
  (0 (Usage Inout)(Type Tap) (Format Range 1 -1 2)(Default 1)
    (Description "Main Tap"))
  (1 (Usage Inout)(Type Tap) (Format Range 0.2 -0.4 0.4)(Default2 0.2)
    (Description "First Post cursor Tap"))
  (2 (Usage Inout)(Type Tap) (Format Range 0.1 -0.1 0.2)(Default 0.1)
    (Description "Second Post cursor Tap"))
)
(RX_DFE_Taps
    (-1 (Usage Inout)(Type Tap) (Format Range 0.2 -0.4 0.4)(Default 0.2)
     (Description "First Precursor Tap"))
    (0 (Usage Inout)(Type Tap) (Format Range 1 -1 2)(Default 1)
      (Description "Main Tap"))
    (1 (Usage Inout)(Type Tap) (Format Range 0.2 -0.4 0.4)(Default2 0.2)
      (Description "First Post cursor Tap"))
)
) | end model_specific

Hope that helps,
Ambrish.
________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of fangyi_rao@xxxxxxxxxxx
Sent: Wednesday, February 10, 2010 9:21 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] question on tap parameters in AMI

Hi, Experts;

I have a question on tap parameter definition in .ami file. The current 
standard states that:

If in addition the individual tap weights are each given a name
which is their tap number (i.e., "-1" is the name of the
first precursor tap, "0" is the name of the main tap, "1" is
the name of the first postcursor tap, etc.) and the tap
weights are declared to be of type Tap, then the EDA platform
can assume that the individual parameters are tap weights in
a tapped delay line

This way we have to assume that Tx only has FFE and Rx only has DFE. What if Rx 
has both FFE and DFE? How can we tell which group of taps is FFE and which is 
for DFE?

Thanks in advance.

Fangyi

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