Machinekit Documentation

HAL Component — LUT5


All instantiable components can be loaded in two manners

Using loadrt with or without count= | names= parameters as per legacy components
Using newinst, which names the instance and allows further parameters and arguments
primarily pincount= which can set the number of pins created for that instance (where applicable)


lut5 — Arbitrary 5-input logic function based on a look-up table




loadrt lut5
newinst lut5 <newinstname> [ pincount=N | iprefix=prefix ] [instanceparamX=X | argX=X ]

( args in [ ] denote possible args and parameters, may not be used in all components )


B lut5

constructs a logic function with up to 5 inputs using a \fBl\fRook-\fBu\fRp \fBt\fRable. The value for \fBfunction\fR can be determined by writing the truth table, and computing the sum of \fBall\fR the \fBweights\fR for which the output value would be \fRtrue\fR. The weights are hexadecimal not decimal so hexadecimal math must be used to sum the weights. A wiki page has a calculator to assist in computing the proper value for function. .PP .PP Note that LUT5 will generate any of the 4,294,967,296 logical functions of 5 inputs so \fBAND\fR, \fBOR\fR, \fBNAND\fR, \fBNOR\fR, \fBXOR\fR and every other combinatorial function is possible. .PP .SS Example Functions A 5-input \fIand\fR function is true only when all the inputs are true, so the correct value for \fBfunction\fR is \fB0x80000000\fR. .PP A 2-input \fIor\fR function would be the sum of \fB0x2\fR + \fB0x4\fR
\fB0x8\fR, so the correct value for \fBfunction\fR is \fB0xe\fR. .PP A 5-input \fIor\fR function is true whenever any of the inputs are true, so the correct value for \fBfunction\fR is \fB0xfffffffe\fR. Because every weight except \fB0x1\fR is true the function is the sum of every line except the first one. .PP A 2-input \fIxor\fR function is true whenever exactly one of the inputs is true, so the correct value for \fBfunction\fR is \fB0x6\fR. Only \fBin-0\fR and \fBin-1\fR should be connected to signals, because if any other bit is \fBtrue\fR then the output will be \fBfalse\fR. .PP .ie '\*[.T]'html' \{\ .HTML \ <STYLE> \ #weight TD { text-align: center; padding-left: .5ex; padding-right: .5ex } \ #weight TH { text-align: center; padding-left: .5ex; padding-right: .5ex } \ #weight TD.W { text-align: right; } \ </STYLE> \ <TABLE ID="weight" STYLE="border: 1px solid black; border-collapse: collapse"> \ <COL SPAN=5 STYLE="margin: .2ex"><COL SPAN=1 STYLE="border-left: 1px solid black"> \ <TR STYLE="border-bottom: 1px solid black"> \ <TH COLSPAN=6>Weights for each line of truth table \ <TR STYLE="border-bottom: 1px solid black"> \ <TH>Bit 4<TH>Bit 3<TH>Bit 2<TH>Bit 1<TH>Bit 0<TH> Weight \ <TR><TD>0<TD>0<TD>0<TD>0<TD>0<TD CLASS="w">0x1 \ <TR><TD>0<TD>0<TD>0<TD>0<TD>1<TD CLASS="w">0x2 \ <TR><TD>0<TD>0<TD>0<TD>1<TD>0<TD CLASS="w">0x4 \ <TR><TD>0<TD>0<TD>0<TD>1<TD>1<TD CLASS="w">0x8 \ <TR><TD>0<TD>0<TD>1<TD>0<TD>0<TD CLASS="w">0x10 \ <TR><TD>0<TD>0<TD>1<TD>0<TD>1<TD CLASS="w">0x20 \ <TR><TD>0<TD>0<TD>1<TD>1<TD>0<TD CLASS="w">0x40 \ <TR><TD>0<TD>0<TD>1<TD>1<TD>1<TD CLASS="w">0x80 \ <TR><TD>0<TD>1<TD>0<TD>0<TD>0<TD CLASS="w">0x100 \ <TR><TD>0<TD>1<TD>0<TD>0<TD>1<TD CLASS="w">0x200 \ <TR><TD>0<TD>1<TD>0<TD>1<TD>0<TD CLASS="w">0x400 \ <TR><TD>0<TD>1<TD>0<TD>1<TD>1<TD CLASS="w">0x800 \ <TR><TD>0<TD>1<TD>1<TD>0<TD>0<TD CLASS="w">0x1000 \ <TR><TD>0<TD>1<TD>1<TD>0<TD>1<TD CLASS="w">0x2000 \ <TR><TD>0<TD>1<TD>1<TD>1<TD>0<TD CLASS="w">0x4000 \ <TR><TD>0<TD>1<TD>1<TD>1<TD>1<TD CLASS="w">0x8000 \ <TR><TD>1<TD>0<TD>0<TD>0<TD>0<TD CLASS="w">0x10000 \ <TR><TD>1<TD>0<TD>0<TD>0<TD>1<TD CLASS="w">0x20000 \ <TR><TD>1<TD>0<TD>0<TD>1<TD>0<TD CLASS="w">0x40000 \ <TR><TD>1<TD>0<TD>0<TD>1<TD>1<TD CLASS="w">0x80000 \ <TR><TD>1<TD>0<TD>1<TD>0<TD>0<TD CLASS="w">0x100000 \ <TR><TD>1<TD>0<TD>1<TD>0<TD>1<TD CLASS="w">0x200000 \ <TR><TD>1<TD>0<TD>1<TD>1<TD>0<TD CLASS="w">0x400000 \ <TR><TD>1<TD>0<TD>1<TD>1<TD>1<TD CLASS="w">0x800000 \ <TR><TD>1<TD>1<TD>0<TD>0<TD>0<TD CLASS="w">0x1000000 \ <TR><TD>1<TD>1<TD>0<TD>0<TD>1<TD CLASS="w">0x2000000 \ <TR><TD>1<TD>1<TD>0<TD>1<TD>0<TD CLASS="w">0x4000000 \ <TR><TD>1<TD>1<TD>0<TD>1<TD>1<TD CLASS="w">0x8000000 \ <TR><TD>1<TD>1<TD>1<TD>0<TD>0<TD CLASS="w">0x10000000 \ <TR><TD>1<TD>1<TD>1<TD>0<TD>1<TD CLASS="w">0x20000000 \ <TR><TD>1<TD>1<TD>1<TD>1<TD>0<TD CLASS="w">0x40000000 \ <TR><TD>1<TD>1<TD>1<TD>1<TD>1<TD CLASS="w">0x80000000 \ </TABLE> \} .el \{\ .TS box tab(;); cb s s s s s cb cb cb cb cb | cb c c c c c | r. Weights for each line of truth table _ Bit 4;Bit 3;Bit 2;Bit 1;Bit 0; Weight _ 0;0;0;0;0;0x1 0;0;0;0;1;0x2 0;0;0;1;0;0x4 0;0;0;1;1;0x8 0;0;1;0;0;0x10 0;0;1;0;1;0x20 0;0;1;1;0;0x40 0;0;1;1;1;0x80 0;1;0;0;0;0x100 0;1;0;0;1;0x200 0;1;0;1;0;0x400 0;1;0;1;1;0x800 0;1;1;0;0;0x1000 0;1;1;0;1;0x2000 0;1;1;1;0;0x4000 0;1;1;1;1;0x8000 1;0;0;0;0;0x10000 1;0;0;0;1;0x20000 1;0;0;1;0;0x40000 1;0;0;1;1;0x80000 1;0;1;0;0;0x100000 1;0;1;0;1;0x200000 1;0;1;1;0;0x400000 1;0;1;1;1;0x800000 1;1;0;0;0;0x1000000 1;1;0;0;1;0x2000000 1;1;0;1;0;0x4000000 1;1;0;1;1;0x8000000 1;1;1;0;0;0x10000000 1;1;1;0;1;0x20000000 1;1;1;1;0;0x40000000 1;1;1;1;1;0x80000000 .TE \}


lut5.N.funct ( OR <newinstname>.funct )

PINS bit in ( OR <newinstname>.in-0 bit in ) bit in ( OR <newinstname>.in-1 bit in ) bit in ( OR <newinstname>.in-2 bit in ) bit in ( OR <newinstname>.in-3 bit in ) bit in ( OR <newinstname>.in-4 bit in )

lut5.N.out bit out ( OR <newinstname>.out bit out )

lut5.N.function u32 io ( OR <newinstname>.function u32 io )