 5.0 Analysis Tutorial - Menu options & the SNA parameter form.

 Below the menus and forms are described as they appear before you.
 ** Actions ** required by the tutorial operator are surrounded by *'s
 Scroll down through this help file to sequentially read about the SNA
 features and perform the desired *** actions *** at the proper 
 point within this help display.

 *********************************************************************
 You need to use the cursor bar on the right side of this help window
 Left  button scrolls=down,right=up, for cursor in this right border ->
 or keybrd up/down arrows move small steps with cursor in this border-> 
 *********************************************************************

 ----------------------------------------------------------------------
 Description of Menu Options:    
             (Onscreen on the far left, these are Middle mouse 
              button picks.  Only Execute & Param are SNA unique)
 ----------------------------------------------------------------------
  --------
 | File-> |  Pulldowns to let you quit or save ... the current
  --------   layout.  Parameter settings are saved within the
             .brd but SNA results are only presevered by the 
             "SAVE RESULTS" button within the SNA execution form.
              
  --------
 | Status |  Brings up control settings for layout interactive editing.
  --------
    
  --------
 | Color  |  Generic control of display and color per class/subclass.
  --------
    
  --------- 
 | Window->| Generic display control, Zoom in or out ...
  ---------
    
  ---------
 | Param   | Brings up the "Signal Analysis" rule setup form displayed.
  ---------

  ---------
 | Execute | Performs analysis including use of selective list of
  ---------  nets, or only loading previously analyzed results as
             defined in the Parameter fillins: "Use Net file" and 
             "Use Report File". Brings up "SNA Execution" and "Delay
             and Distortion" forms described later.
  ---------
 | Edit->  | Layout editing and SNA "Analyze Again" can be iterated.
  ---------  Editing commands should be "Done" before "Analyze again"

  ---------
 | Slide   | Slide editing is particularly useful to reduce crosstalk.
  ---------
    
  ---------
 | Hilite->| (& Dehilite) Permanent hilites are separate from the SNA
  ---------  hiliting of the current NET and Crosstalk violation segs.
    
  ---------
 | Show->  | ->Elements   (For geometric information)
  ---------  ->Parasitics (For impedances, & propagation delays))
    
  ---------
 | Define->| ->Property_Nets [ >] DELAY_RULE=_____ is checked per net.
  ---------  ->Cross_Section  is also important to SNA


 ======================================================================
  -------  Note: This Param command was used within the tutorial script
 | Param | to open the SIGNAL ANALYSIS Form being displayed on the left
  -------  (Form shown is all defaults, except Use Net File is checked)
 ======================================================================

 ------------------
 Signal Analysis
 ------------------
   --------------  (Threshold rules/budget for Noise ingredients)
    Noise Rules:    accessed through  
   --------------  
  MAX UNDERSHOOT      Ringing of waveform back into a midrange voltage.

  MAX BACK CROSSTALK  Dominant backwards crosstalk ingredient.

  MAX THERMAL SHIFT   Mismatched voltage thresholds caused by  high or 
                      unequal driver & receiver junction temperatures.

  MAX OHMIC LOSS      Worstcase voltage drop due to etch dc resistance.

  MAX EXTERNAL NOISE  Not predicted, a user definable net property.

  MIN NOISE MARGIN    Rule for the remainder after subtracting all the 
                      above noise ingredients from the technology's 
                      Noise Immunity.  Unlike noise ingredients with 
                      max rules to be kept below, this rule seeks a 
                      large value or at least a MINIMUM positive number.


  MAX OVERSHOOT       Violations cause chip failure, but are not 
                      subtracted to yield the Noise Margin since this 
                      too-hi-hi or too-low-low is never a logic error. 
                      (The above Noise Margin ingredient rules represent
                      the risks of noise to disrupt signals into the 
                      midrange)

  MAX FORW CROSSTALK  Generally this forward ingredient is less than 
                      the backwards crosstalk. Forward crosstalk
                      has its own rule but only the backwards crosstalk
                      is considered into the total subtraction to 
                      predict a pessimistic Noise Margin. (Forward and
                      backward crosstalk propagate in opposite
                      directions along each offended neighbor net but
                      for crosstalk, SNA simply ignores directionality,
                      as if each net were considered as bidirectional.)


     --------------
      Delay Rules:  (Threshold rules/budgets for Driver-Receiver timing)
      -------------
   MAX VIA COUNT     Rule limiting the intervening number of vias.

   MIN PROPAGATION   Length(accounting for speed-per-layer) must be 
                     such to meet this min delay.

   MAX PROPAGATION   Length (accounting for speed-per-layer) must be 
                     such to meet this max delay.

   MAX FIRST SWITCH  Max delay for the receiver to see the rise/fall 
                     transition completed to its hi/low threshold 
                     voltage. I.e , the length oriented propagation 
                     delay plus/minus any distortion in the driver's 
                     risetime as seen at the receiver pin.

   MAX FINAL SETTLE  First switch delay + any added time required for
                     ringing (undershoot) to settle down.

    

[] VERIFY MONOTONIC EDGE     Check or skip verification that the 
                             rise/fall occurs without any glitch 
                             reversal into the midrange voltage. 
                             (Prevents clocking errors on edge 
                             triggered nets.)

[] VERIFY FIRST INCIDENT     Check or skip verification 
   SWITCHING                 that switch delay looks heuristically 
                             reasonable, i.e. <= 1.5x the sum of the 
                             driver risetime plus the propagation delay.


[] USE NET FILE:________     If checked only those netnames listed in 
                             the indicated text file are analyzed. Also
                             allows users to check critical nets or nets
                             grouped by different technologies, clocks 
                             vs data ...   

[] USE REPORT FILE:_____     If checked SNA attempts to load previously
                             analyzed result data from the indicated 
                             file and will only analyze remaining 
                             selected nets whose previous analysis was
                             not available.  This bulk data report can 
                             be generated by batch signoise or can be 
                             the "Save Results" from a previous SNA 
                             execution.

[] SAVE WAVEFORM FILES       If checked a DRIVER.sim ASCII file will be 
                             saved in the current working directory for
                             each driver on each net being newly 
                             analyzed (not simply loaded from a 
                             "Use report_") **WARNING*SAVING WAVEFORMS 
                             TAKES TIME & QUICKLY FILLS YOUR DISK**
                             This option should be used sparingly, ie 
                             only to resolve concerns.  The separate 
                             etchwave waveform display tool will
                             automatically display the waveform 
                             predicted at the driver and receiver pins.

                             -----------------
                             Note that these waveforms represent the
                             timing, overshoot and undershoot data, but
                             do not include the other noise ingredients 
                             such as crosstalk which are not considered
                             in the time domain.  When this is checked 
                             the etchwave window will also self-update
                             as you step through nets for which .sim 
                             files exist.
  


 *****************************
 *                           *  F1 is a script to [EXECUTE] to bring up 
 * PRESS keyboard  <F1> NOW! *  and reposition the  DELAY & DISTORTION 
 * (Then continue scrolling  *  and SIGNAL ANALYSIS EXECUTION  forms.
 *  down through this help   *
 *  window)                  *
 *****************************

 Only Press <F2> if you want to skip ahead to view sorted SNA results 


 ----------------------------- 
   Signal Analysis Execution   (Control buttons & fillin-or-report the
 -----------------------------  current NET and pin-pair info.)

 NETWORK:_____  This Reports the current netname as you "Next..." step
                through the  results. You can also pick the fillin slot
                to type an explicit netname whose results you now wish
                to view.

 DRIVER:______  This Reports the current driver pin as you "Next..." 
                step through the  results. You can also pick the fillin
                slot to type an explicit driver pin whose results you 
                wish to view.  Results are always  available for each 
                driver-receiver pin combination per net even though 
                some ingredients such as crosstalk are only 
                pessimistically predicted on a per entire net basis.

 RECEIVER:____   Report or fillin request for current receiver pin.

 SORT BY: [????] Middle button hold-down picking the boxed value 
                 displays a pulldown menu which lets you sort the
                 pin-pairs by netname alphabetic) or by values
                 predicted for each SNA rule-check. 

 [FIRST] [PREV] [NEXT]     Allows you to step around through the sorted 
                           data results per pin-pair.

   ( )PIN    or 
   (*)NET    toggles the Next...stepping through the sorted data to the 
             next pin pair or next pin pair on a different netname.

   (*)RISE   or
   ( )FALL   Selects analysis of either case. (often asymetric)

   [ANALYZE AGAIN] Re-analyzes the predictions for all pin pairs on 
                   the currently displayed net.  This is especially 
                   appropriate following interactive layout editing 
                   to reduce crosstalk...

   [SAVE RESULTS]  Prompts you for a "Report file name" in which to 
                   save all of the nets' analysis results analyzed or
                   loaded previously by this SNA execution session. 
                   (For later "Use report___")

   [RAPIDSIM OUT]  Creates a wire.dly file, complete in Valid's Logic
                   workbench syntax, including the pin-to-pin delay for
                   all nets and pin pairs for which SNA data has been 
                   loaded or analyzed in this Execute. The wire.dly can
                   be either all propagation, all switch, or all settle
                   delays, depending on the middle button pulldown 
                   setting of the: UNTIL:  [ Propagation/Switch/Settle]


 ----------------------------------------------------------------------
  DELAY & DISTORTION  (This shows the actual SNA predicted results for
 --------------------- the current Network:Driver:Receiver  pin-pair.
                       RULE VIOLATION VALUES HAVE A "*"  APPENDED)

 NOISE IMMUNITY        This is extracted per driver and receiver model
                       technology out of the elecmodel.dat library file.

 - BACKWARD CROSSTALK  Prediction for this net.

 - UNDERSHOOT          Prediction for this receiver from this driver.

 - OHMIC LOSS          Worstcase etch resistance for this pin-pin path.

 - THERMAL SHIFT       Predicted shift in the driver versus receiver 
                       threshold voltages due to individual junction 
                       temperatures of the driver & receiver components.

 - EXTERNAL NOISE      Escape valve property. Whatever the user has set
                       per net. (Ground noise or offboard cabling noise
                       can be user input).  
 -----------------
  NOISE MARGIN         Subtraction of above 5 values from Noise Immunity
                       (This is your leeway, desired to be positive)

   OVERSHOOT           Predicted too-hi-hi or too-low-low. (Destroys 
                       diodes)

   FORWARD CROSSTALK   Alternative crosstalk mode assumed to be smaller 
                       than the backward crosstalk but provided
                       separately for completeness.

   PROPAGATION DELAY   Predicted Delay due to length/layers.

   FIRST SWITCH DELAY  Predicted Delay including + or - in rise/fall

   FINAL SETTLE DELAY  Switch delay plus any added time for the waveform
                       to settle outside of the elecmodel.dat midrange.

   FRIST INCIDENT SW.  PASS or FAIL*   Check for First Switch Delay,
                       Delay <= 1.5*(propagation+rise-or-fall)

   MONOTONIC RISE/FALL PASS or FAIL* Check to verify there are no slope
                       reversals in the midrange, which could cause 
                       double clocking on edge triggered nets.

   DELAY_RULE checks:  If this net possess any explicit DELAY_RULE 
                       property settings they are reported and *'ed 
                       if violated.

  MINIMUM DELAY 
  MAXIMUM DELAY
  MAXIMUM VIA #         These 3 rules from the current SNA parameter 
                        setting are displayed for comparison against 
                        the propagation delay and the number of vias 
                        between the current driver & receiver pin-pair.
               

  Driver Model: OUT/BI/TRI TECHNOLOGY  
  Receiver Model IN/BI     TECHNOLOGY  
         Here are shown the Driver and receiver pinuse codes from their
         device library and the relevant model technology within
         elecmodel.dat which is being used.  Users should verify that
         these are correct. Technology "VALID_DEFAULT" is always an
         indication modeling has NOT been setup correctly by the user.


  No driver   J_TEMPERATURE property
  No receiver J_TEMPERATURE property
 The final 2 messages report how thermal noise cannot be predicted when
 driver and receiver Junction temperature properties have not previously
 been predicted by Allegro ThermoStats, or explicitly set by the user.
          


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 Press <F1> to continue to viewing sorted SNA results ...
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