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</P>

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<A NAME="pgfId=47438">

 </A>

=</P>

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<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47440">

 </A>

R<SUB CLASS="Subscript">

P2</SUB>

(C<SUB CLASS="Subscript">

P2</SUB>

 + C<SUB CLASS="Subscript">

2</SUB>

 + 3C<SUB CLASS="Subscript">

P1</SUB>

) + (R<SUB CLASS="Subscript">

P2</SUB>

 + R<SUB CLASS="Subscript">

P1</SUB>

)(3C<SUB CLASS="Subscript">

P1</SUB>

 + C<SUB CLASS="Subscript">

3</SUB>

 + C<SUB CLASS="Subscript">

P2</SUB>

) </P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnNumber">

<A NAME="pgfId=47442">

 </A>

(7.9)</P>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47444">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47446">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47448">

 </A>

 + (2R<SUB CLASS="Subscript">

P2</SUB>

 + R<SUB CLASS="Subscript">

P1</SUB>

)(C<SUB CLASS="Subscript">

P2</SUB>

 + C<SUB CLASS="Subscript">

4</SUB>

) .</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqn">

<A NAME="pgfId=47450">

 </A>

&nbsp;</P>

</TD>

</TR>

</TABLE>

<P CLASS="Body">

<A NAME="pgfId=13322">

 </A>

If <SPAN CLASS="EquationNumber">

RP1</SPAN>

 = <SPAN CLASS="EquationNumber">

RP2</SPAN>

, and <SPAN CLASS="EquationNumber">

CP1</SPAN>

 = <SPAN CLASS="EquationNumber">

CP2</SPAN>

, then  </P>

<TABLE>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47534">

 </A>

<SPAN CLASS="Symbol">

t</SPAN>

<SUB CLASS="SubscriptVariable">

D</SUB>

<SUB CLASS="Subscript">

</SUB>

</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47536">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47538">

 </A>

(15 + 21)R<SUB CLASS="Subscript">

P</SUB>

C<SUB CLASS="Subscript">

P</SUB>

 + (1.5 + 1 + 4.5)R<SUB CLASS="Subscript">

P</SUB>

C<SUB CLASS="Subscript">

LX</SUB>

 .</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnNumber">

<A NAME="pgfId=47540">

 </A>

(7.10)</P>

</TD>

</TR>

</TABLE>

<P CLASS="Body">

<A NAME="pgfId=13339">

 </A>

We need to know the pass-transistor resistance <SPAN CLASS="EquationNumber">

RP </SPAN>

. For example, suppose <SPAN CLASS="EquationNumber">

RP</SPAN>

 = 1k<SPAN CLASS="Symbol">

W</SPAN>

 . If <IMG SRC="CH07-7.gif" ALIGN="BASELINE">

k<SUP CLASS="Superscript">

'</SUP>

<SUB CLASS="Subscript">

n</SUB>

= 50 <SPAN CLASS="Symbol">

m</SPAN>

AV<SUP CLASS="Superscript">

&#8211;2</SUP>

, then (with <SPAN CLASS="EquationNumber">

Vt</SPAN>

<SPAN CLASS="EquationVariables">

n</SPAN>

 = 0.65 V and <SPAN CLASS="EquationVariables">

V</SPAN>

<SUB CLASS="Subscript">

DD</SUB>

 = 3.3 V)  </P>

<TABLE>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47575">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47577">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47579">

 </A>

1</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47581">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47583">

 </A>

1</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47673">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47585">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqn">

<A NAME="pgfId=47587">

 </A>

&nbsp;</P>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47589">

 </A>

W/L</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47591">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47593">

 </A>

&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47595">

 </A>

<SUB CLASS="SubscriptVariable">

=</SUB>

</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47597">

 </A>

&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;&#8211;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47675">

 </A>

<SUB CLASS="SubscriptVariable">

=</SUB>

</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47599">

 </A>

7.5 .</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnNumber">

<A NAME="pgfId=47601">

 </A>

(7.11)</P>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47603">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47605">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47607">

 </A>

k<SUP CLASS="Superscript">

'</SUP>

<SUB CLASS="Subscript">

n</SUB>

R<SUB CLASS="Subscript">

p</SUB>

(<SPAN CLASS="EquationVariables">

V</SPAN>

<SUB CLASS="SubscriptVariable">

DD</SUB>

 &#8211; V<SUB CLASS="Subscript">

t</SUB>

<SUB CLASS="SubscriptVariable">

n</SUB>

)</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47609">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47611">

 </A>

(50 <SPAN CLASS="Symbol">

&#165;</SPAN>

 10<SUP CLASS="Superscript">

&#8211;6</SUP>

)(1 <SPAN CLASS="Symbol">

&#165;</SPAN>

 10<SUP CLASS="Superscript">

3</SUP>

)(3.3 &#8211; 0.65)</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47677">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47613">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqn">

<A NAME="pgfId=47615">

 </A>

&nbsp;</P>

</TD>

</TR>

</TABLE>

<P CLASS="Body">

<A NAME="pgfId=13345">

 </A>

If L = 1 <SPAN CLASS="Symbol">

m</SPAN>

m, both source and drain areas are 7.5 <SPAN CLASS="Symbol">

m</SPAN>

m long and approximately 3 <SPAN CLASS="Symbol">

m</SPAN>

m wide (determined by diffusion overlap of contact, contact width, and contact-to-gate spacing, rules 6.1a + 6.2a + 6.4a = 5.5 <SPAN CLASS="Symbol">

l</SPAN>

 in <A HREF="/Humuhumu/from Antibes/Prof.htm#23193" CLASS="XRef">

Table&nbsp;2.7</A>

). Both drain and source areas are thus 23 <SPAN CLASS="Symbol">

m</SPAN>

m<SUP CLASS="Superscript">

2</SUP>

 and the sidewall perimeters are 14 <SPAN CLASS="Symbol">

m</SPAN>

m (excluding the sidewall facing the channel). If we have a diffusion capacitance of 140 aF<SPAN CLASS="Symbol">

m</SPAN>

m<SUP CLASS="Superscript">

&#8211;2</SUP>

 (area) and 500 aF<SPAN CLASS="Symbol">

m</SPAN>

m<SUP CLASS="Superscript">

&#8211;1</SUP>

 (perimeter), typical values for a 1.0 <SPAN CLASS="Symbol">

m</SPAN>

m process, the parasitic source and drain capacitance is  </P>

<TABLE>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47681">

 </A>

C<SUB CLASS="Subscript">

P</SUB>

</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47683">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47685">

 </A>

(140 <SPAN CLASS="Symbol">

&#165;</SPAN>

 10<SUP CLASS="Superscript">

&#8211;18</SUP>

)(23) + (500 <SPAN CLASS="Symbol">

&#165;</SPAN>

 10<SUP CLASS="Superscript">

&#8211;18</SUP>

)(14)</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnNumber">

<A NAME="pgfId=47687">

 </A>

(7.12)</P>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47716">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47718">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47720">

 </A>

1.022 <SPAN CLASS="Symbol">

&#165;</SPAN>

 10<SUP CLASS="Superscript">

&#8211;14</SUP>

 F .</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqn">

<A NAME="pgfId=47722">

 </A>

&nbsp;</P>

</TD>

</TR>

</TABLE>

<P CLASS="Body">

<A NAME="pgfId=13334">

 </A>

If we assume <SPAN CLASS="EquationNumber">

CP</SPAN>

 = 0.01 pF and <SPAN CLASS="EquationNumber">

CLX</SPAN>

 = 0.075 pF (<A HREF="CH07.2.htm#38131" CLASS="XRef">

Table&nbsp;7.3</A>

),  </P>

<TABLE>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47732">

 </A>

<SPAN CLASS="Symbol">

t</SPAN>

<SUB CLASS="Subscript">

D</SUB>

</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47734">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47736">

 </A>

(36)(1)(0.01) + (7)(1)(0.075)</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnNumber">

<A NAME="pgfId=47738">

 </A>

(7.13)</P>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnRight">

<A NAME="pgfId=47740">

 </A>

&nbsp;</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnCenter">

<A NAME="pgfId=47742">

 </A>

=</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqnLeft">

<A NAME="pgfId=47744">

 </A>

0.885 ns .</P>

</TD>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableEqn">

<A NAME="pgfId=47746">

 </A>

&nbsp;</P>

</TD>

</TR>

</TABLE>

<P CLASS="BodyAfterHead">

<A NAME="pgfId=31535">

 </A>

A delay of approximately 1 ns agrees with the typical values from the XACT delay calculator and is about the fastest connection we can make between two CLBs.</P>

<TABLE>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableFigure">

<A NAME="pgfId=31563">

 </A>

&nbsp;</P>

<DIV>

<IMG SRC="CH07-8.gif">

</DIV>

</TD>

</TR>

<TR>

<TD ROWSPAN="1" COLSPAN="1">

<P CLASS="TableFigureTitle">

<A NAME="pgfId=31566">

 </A>

FIGURE&nbsp;7.7&nbsp;<A NAME="26676">

 </A>

The Xilinx EPLD UIM (Universal Interconnection Module). (a)&nbsp;A simplified block diagram of the UIM. The UIM bus width, <SPAN CLASS="EquationVariables">

n</SPAN>

, varies from 68 (XC7236) to 198 (XC73108). (b)&nbsp;The UIM is actually a large programmable AND array. (c)&nbsp;The parasitic capacitance of the EPROM cell.</P>

</TD>

</TR>

</TABLE>

<HR><P>[&nbsp;<A HREF="CH07.htm">Chapter&nbsp;start</A>&nbsp;]&nbsp;[&nbsp;<A HREF="CH07.1.htm">Previous&nbsp;page</A>&nbsp;]&nbsp;[&nbsp;<A HREF="CH07.3.htm">Next&nbsp;page</A>&nbsp;]</P></BODY>



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