ch13.4.htm

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*</P>
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t1x</P>
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x -&gt; 0</P>
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*</P>
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*</P>
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*</P>
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*</P>
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tx0</P>
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x -&gt; z</P>
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*</P>
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*</P>
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*</P>
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*</P>
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txz</P>
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z -&gt; x</P>
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*</P>
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*</P>
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*</P>
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*</P>
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tzx</P>
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* See <A HREF="ch13.4.htm#57065" CLASS="XRef">
See Specifying x transition delays</A>
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<DIV>
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<P CLASS="SubSection">
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<A NAME="57065">
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Specifying x transition delays</P>
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If the x transition delays are not explicitly specified, the calculation of delay values for x transitions is based on the following two pessimistic rules:</P>
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<LI CLASS="DashedList">
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Transitions from a known state to <CODE CLASS="code">
x</CODE>
 shall occur as quickly as possible--that is, the shortest possible delay shall be used for any transition from <CODE CLASS="code">
x</CODE>
.</LI>
<LI CLASS="DashedList">
<A NAME="pgfId=436">
 </A>
Transitions from <CODE CLASS="code">
x</CODE>
 to a known state shall take as long as possible--that is, the longest possible delay shall be used for any transition to <CODE CLASS="code">
x</CODE>
.</LI>
</UL>
<P CLASS="Body">
<A NAME="pgfId=545">
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<A HREF="ch13.4.htm#21396" CLASS="XRef">
See : Calculating delays for x transitions</A>
<A NAME="marker=230">
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 <A NAME="marker=231">
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presents the general algorithm for calculating delay values for x transitions, along with specific examples. The following two groups of x transitions are represented in the table:</P>
<OL>
<P CLASS="NumberedLista">
<A NAME="pgfId=546">
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a)	transition from a known state <CODE CLASS="code">
s</CODE>
 to <CODE CLASS="code">
x</CODE>
:  <CODE CLASS="code">
s</CODE>
 ' <CODE CLASS="code">
x</CODE>
</P>
<P CLASS="NumberedListb">
<A NAME="pgfId=577">
 </A>
b)	transition from <CODE CLASS="code">
x</CODE>
 to a known state <CODE CLASS="code">
s</CODE>
:  <CODE CLASS="code">
x</CODE>
 ' <CODE CLASS="code">
s</CODE>
</P>
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<TABLE BORDER="1">
<CAPTION>
<P CLASS="TableTitle">
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Table&nbsp;13-4<A NAME="21396">
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: Calculating delays for x transitions<A NAME="marker=237">
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</P>
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<TR>
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<P CLASS="CellHeading">
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X transition</P>
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<TH ROWSPAN="1" COLSPAN="1">
<P CLASS="CellHeading">
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Delay Value</P>
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<TR>
<TD ROWSPAN="1" COLSPAN="2">
<P CLASS="CellHeading">
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general algorithm</P>
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s ' x</P>
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<TD ROWSPAN="1" COLSPAN="1">
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minimum ( s ' other known signals )</P>
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x ' s</P>
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maximum ( other known signals ' s )</P>
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<TR>
<TD ROWSPAN="1" COLSPAN="2">
<P CLASS="CellHeading">
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specific transitions</P>
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0 ' x</P>
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<TD ROWSPAN="1" COLSPAN="1">
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minimum ( 0 ' z delay, 0 ' 1 delay )</P>
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<P CLASS="CellBody">
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1 ' x</P>
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<TD ROWSPAN="1" COLSPAN="1">
<P CLASS="CellBody">
<A NAME="pgfId=497">
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minimum ( 1 ' z delay, 1 ' 0 delay )</P>
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z ' x</P>
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<TD ROWSPAN="1" COLSPAN="1">
<P CLASS="CellBody">
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minimum ( z ' 1 delay, z ' 0 delay )</P>
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x ' 0</P>
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maximum ( z ' 0 delay, 1 ' 0 delay )</P>
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x ' 1</P>
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<P CLASS="CellBody">
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maximum ( z ' 1 delay, 0 ' 1 delay )</P>
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<P CLASS="CellBody">
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x ' z</P>
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<TD ROWSPAN="1" COLSPAN="1">
<P CLASS="CellBody">
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maximum ( 1 ' z delay, 0 ' z delay )</P>
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usage:     (C =&gt; Q)  =  (5, 12, 17, 10, 6, 22) ;</P>
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0 ' x</P>
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minimum ( 17, 5 ) = 5</P>
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1 ' x</P>
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minimum ( 6, 12 ) = 6</P>
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z ' x</P>
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minimum ( 10, 22 ) = 10</P>
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x ' 0</P>
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maximum ( 22, 12 ) = 22</P>
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x ' 1</P>
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maximum ( 10, 5 ) = 10</P>
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x ' z</P>
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maximum ( 6, 17 ) = 17</P>
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</TABLE>
</DIV>
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