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BIRD ID#:	 123  
ISSUE TITLE:     IBIS-AMI New Reserved Parameters for Jitter/Noise 
REQUESTER: 	 Walter Katz, Mike Steinberger, Todd Westerhoff, SiSoft
DATE SUBMITTED:  October 20, 2010
DATE REVISED:    
DATE ACCEPTED BY IBIS OPEN FORUM:

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STATEMENT OF THE ISSUE:

Model developers and EDA vendors building IBIS-AMI models using the IBIS 5.0 
specification have come across a number of modeling issues that are not 
addressed in IBIS 5.0.  In order to deliver models and EDA tools that meet 
end-user demands for model accuracy and functionality, EDA vendors have defined 
"extensions" to add new capabilities to IBIS-AMI models.  Unfortunately, 
EDA vendors have had to use proprietary (and different) syntax to add these 
capabilities to models, limiting model portability between different EDA tools.

This BIRD proposes new syntax for the .ami control file that improves model 
functionality and accuracy.  Including this syntax in the IBIS standard will 
allow creation of accurate, compliant IBIS-AMI models that are readily portable 
between commercial EDA simulators.   

The parameters defined in this document are to be added in Section 6c of the 
IBIS 5.0 specification as new Reserved_Parameters.  

Jitter, Noise and Clock Modeling
Tx_Rj, Tx_Sj, Tx_Sj_frequency, Rx_Clock_Recovery_Mean, Rx_Clock_Recovery_Rj, 
Rx_Clock_Recovery_Sj, Rx_Clock_Recovery_DCD, Rx_Rj, Rx_Sj, Rx_DCD, Rx_Noise

The following parameter exists in the IBIS 5.0 specification but its definition 
is replaced using the text in this BIRD:

Tx_DCD

Note that all of the parameters defined in this BIRD may be declared in the 
Model_Specific section of the .ami file to allow the use of some legacy models.  
However, using these parameters in the Model_Specific section of the .ami file 
is considered legacy use and will likely be deprecated in IBIS versions beyond 
5.1.

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On page 146 replace:

|               Tx_DCD:
|
|               Tx_DCD (Transmit Duty Cycle Distortion) can be of Usage Info
|               and Out.  It can be of Type Float and UI and can have Data
|               Format of Value, Range and Corner.  It tells the EDA platform
|               the maximum percentage deviation of the duration of a
|               transmitted pulse from the nominal pulse width.  Example of
|               TX_DCD declaration is:
|
|              (Tx_DCD (Usage Info)(Type Float)
|                      (Format Range <typ> <min> <max>)) 

with:

|               Tx_DCD:
|
|               Tx_DCD (Transmit Duty Cycle Distortion) can be of Usage Info
|               or Out.  It can be of Type Float and UI and can have Data
|               Format of Value, Range and Corner.  It defines half the peak
|               to peak clock duty cycle distortion, in seconds or UI, to be
|               added to the behavior implemented directly by the transmitter
|               model.  
|
|               Example of TX_DCD declaration is:
|
|       (Tx_DCD (Usage Info)(Corner 0.008 0.016 0.005)(Type UI)
|          (Description "TX Duty Cycle Distortion in UI.")
|       )
 
 
The following text is added immediately before Table 1 on page 148: 

| Jitter, Noise and Clock Parameters
| 
| The following optional Reserved Parameters are used to specify impairments for 
| the transmitter output.  These budgets specify the impairment as measured at 
| the TX output (i.e. the transmitter output is expected to be directly modulated 
| by these amounts).  This data is used by the simulator to either modify the 
| input presented to the algorithmic model or when post-processing the results 
| from the model; the budget values specified by these parameters are not passed 
| directly to the model itself.
| 
| 
| "Tx_Rj" is an AMI parameter of Type either Float or UI and Usage either Info or 
| Out which defines the standard deviation, in seconds or UI, of a Gaussian phase 
| noise process at the transmitter which is to be added to the behavior 
| implemented directly by the transmitter model.
| 
| Example:
| 
|       (Tx_Rj (Usage Info)(Corner 0.005 0.006 0.004)(Type UI)
|          (Description "TX Random Jitter in UI.")
| )
| 
| 
| "Tx_Sj" is an AMI parameter of Type either Float or UI and Usage either Info 
| or Out which defines half the peak to peak amplitude, in seconds or UI, of a 
| sinusoidal jitter which is to be added to the behavior implemented directly 
| by the transmitter model.
| 
| Example:
| 
|       (Tx_Sj (Usage Info)(Corner 0.05 0.07 0.4)(Type UI)
|          (Description "TX Sinusoidal Jitter in UI.")
| )
| 
| 
| "Tx_Sj_frequency" is an AMI parameter of Type Float and Usage either Info or 
| Out which defines the frequency, in Hertz, of the sinusoidal jitter at the 
| transmitter.
| 
| Example:
| 
|       (Tx_Sj_Frequency (Usage Info)(Corner 6.5E7 6.5E7 6.5E7)(Type UI)
|          (Description "TX Sinusoidal Jitter Frequency in Hz.")
| )
| 
| 
| "Tx_DCD" is an AMI parameter of Type either Float or UI and Usage either Info 
| or Out which defines half the peak to peak clock duty cycle distortion, in 
| seconds or UI, to be added to the behavior implemented directly by the 
| transmitter model.
| 
| Example:
| 
|        (Tx_DCD (Usage Info)(Corner 0.008 0.016 0.005)(Type UI)
|           (Description "TX Duty Cycle Distortion in UI.")
| )
| 
| 
| The following optional Reserved Parameters are used to specify characteristics 
| of the receiver’s recovered clock when the model does not return clock_ticks 
| information from an AMI_Getwave call. This data is used by the simulator when 
| post-processing the results from the model; the budget values specified by these 
| parameters are not passed directly to the model itself.
| 
| "Rx_Clock_Recovery_Mean" is an AMI parameter of Type either Float or UI and 
| Usage either Info or Out which defines a static offset, in seconds or UI, 
| between the recovered clock and the median threshold crossing time in the eye 
| diagram plus one half bit period.
| 
| Example:
| 
|       (Rx_Clock_Recovery_Mean (Usage Info)(Value 0.05)
|          (Type UI)(Description "Recovered Clock offset in UI.")
| )
| 
| 
| "Rx_Clock_Recovery_Rj" is an AMI parameter of Type either Float or UI and 
| Usage either Info or Out which defines the standard deviation, in seconds 
| or UI, of a Gaussian phase noise exhibited by the recovered clock.
| 
| Example:
| 
|       (Rx_Clock_Recovery_Rj (Usage Info)(Corner 0.005 0.006 0.004)
|          (Type UI)(Description "RX Random Clock Jitter in UI.")
| )
| 
| 
| "Rx_Clock_Recovery_Sj" is an AMI parameter of Type either Float or UI and 
| Usage either Info or Out which defines half the peak to peak variation, 
| in seconds or UI, of a sinusoidal phase noise exhibited by the recovered 
| clock.
| 
| Example:
| 
|       (Rx_Clock_Recovery_Sj (Usage Info)(Corner 0.05 0.07 0.4)(Type UI)
|          (Description "RX Sinusoidal Jitter in UI.")
| )
| 
| 
| "Rx_Clock_Recovery_DCD" is an AMI parameter of Type either Float or UI and 
| Usage either Info or Out which defines half the peak to peak variation, 
| in seconds or UI, of a clock duty cycle distortion exhibited by the 
| recovered clock.
| 
| Example:
| 
|       (Rx_Clock_Recovery_DCD (Usage Info)(Corner 0.008 0.016 0.005)
|    (Type UI)(Description "RX Duty Cycle Distortion in UI.")
| )
| 
| 
| The following optional Reserved Parameters are used to modify the statistics 
| associated with receiver’s recovered clock when the model returns clock ticks 
| information from an AMI_Getwave call. This data is used by the simulator 
| when post-processing the results from the model; the budget values specified 
| by these parameters are not passed directly to the model itself. 
| 
| "Rx_Rj" is an AMI parameter of Type either Float or UI and Usage either Info 
| or Out which defines the standard deviation, in seconds or UI, of a Gaussian 
| phase noise driven by impairments external to the receiver. This phase noise 
| is to be accounted for in both Statistical and Time-Domain simulations. 
| 
| Example:
| 
|       (Rx_Rj (Usage Info)(Corner 0.005 0.006 0.004)(Type UI)
|          (Description "RX Random Jitter in UI.")
| )
| 
| 
| "Rx_Sj" is an AMI parameter of Type either Float or UI and Usage either Info 
| or Out which defines half the peak to peak variation, in seconds or UI, of 
| a sinusoidal phase noise driven by impairments external to the receiver. 
| This phase noise is to be accounted for in both Statistical and Time-Domain 
| simulations.
| 
|       (Rx_Sj (Usage Info)(Corner 0.05 0.07 0.4)(Type UI)
|          (Description "RX Sinusoidal Jitter in UI.")
| )
| 
| 
| "Rx_DCD" is an AMI parameter of Type either Float or UI and Usage either Info 
| or Out which defines half the peak to peak variation, in seconds or UI, of a 
| clock duty cycle distortion driven by impairments external to the receiver. 
| This phase noise is to be accounted for in both Statistical and Time-Domain 
| simulations.
| 
| Example:
| 
|       (Rx_DCD (Usage Info)(Corner 0.008 0.016 0.005)(Type UI)
|          (Description "RX Duty Cycle Distortion in UI.")
| )
| 
|  
| The following optional Reserved Parameter is used to modify the statistics 
| associated with the data input to the receiver’s sampling latch.  This data 
| is used by the simulator when post-processing the results from the model; 
| the budget values specified by this parameter are not passed directly to 
| the model itself.
| 
| 
| "Rx_Noise" is an AMI parameter of Type Float and Usage either Info or Out 
| which defines the standard deviation, in volts into a 100 ohm differential 
| load, of a set of independent samples of a Gaussian noise process measured 
| at the input of a receiver.
| 
| Example:
| 
|       (Rx_Noise (Usage Info)(Format Corner 0.0030 0.0035 0.0025)
|          (Type Float)(Description "RX amplitude noise in V.")
| )
| 
 
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ANALYSIS PATH/DATA THAT LED TO SPECIFICATION


The parameters defined in this BIRD came from commercial IBIS-AMI model 
development efforts where new functionality was needed to meet customer 
expectations for model functionality, accuracy and performance.  The parameters 
in this BIRD were defined by SiSoft and its semiconductor partners.  These 
parameters are being contributed to IBIS to ensure IBIS-AMI model accuracy 
and portability.

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ANY OTHER BACKGROUND INFORMATION:

This BIRD is being requested by the following IBIS users and model developers, in conjunction with the authors:

Cisco Systems: Upen Reddy, Doug White 
Ericsson: Anders Ekholm
Broadcom: Yunong Gan
IBM: Adge Hawes
TI: Alfred Chong, Srikanth Sundaram

BIRDs 121 through 124 split the concepts and changes of BIRD 119 into separate
documents. 

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