Progress in presentation

manual/PRESENTATION_ExAdv.tex

@@ -239,6 +239,51 @@ show -color red @cone_ab -color magenta @cone_a -color blue @cone_b
 \subsectionpagesuffix
 \end{frame}
 
+\subsubsection{Introduction to techmap}
+
+\begin{frame}{\subsubsecname}
+\begin{itemize}
+\item
+The {\tt techmap} command replaces cells in the design with implementations given
+as verilog code (called ``map files''). It can replace Yosys' internal cell
+types (such as {\tt \$or}) as well as user-defined cell types.
+\medskip\item
+Verilog parameters are used extensively to customize the internal cell types.
+\medskip\item
+Additional special parameters are used by techmap to communicate meta-data to the
+map files.
+\medskip\item
+Special wires are used to instruct techmap how to handle a module in the map file.
+\medskip\item
+Generate blocks and recursion are powerful tools for writing map files.
+\end{itemize}
+\end{frame}
+
+\begin{frame}[t]{\subsubsecname -- Example 1/2}
+\vskip-0.2cm
+To map the Verilog OR-reduction operator to 3-input OR gates:
+\vskip-0.2cm
+\begin{columns}
+\column[t]{0.35\linewidth}
+\lstinputlisting[xleftmargin=0.5cm, basicstyle=\ttfamily\fontsize{7pt}{8pt}\selectfont, language=verilog, lastline=24]{PRESENTATION_ExAdv/red_or3x1_map.v}
+\column[t]{0.65\linewidth}
+\lstinputlisting[xleftmargin=0.5cm, basicstyle=\ttfamily\fontsize{7pt}{8pt}\selectfont, language=verilog, firstline=25]{PRESENTATION_ExAdv/red_or3x1_map.v}
+\end{columns}
+\end{frame}
+
+\begin{frame}[t]{\subsubsecname -- Example 2/2}
+\vbox to 0cm{
+\hfil\includegraphics[width=10cm,trim=0 0cm 0 0cm]{PRESENTATION_ExAdv/red_or3x1.pdf}
+\vss
+}
+\begin{columns}
+\column[t]{6cm}
+\column[t]{4cm}
+\vskip-0.6cm\lstinputlisting[basicstyle=\ttfamily\fontsize{8pt}{10pt}\selectfont, language=ys, firstline=4, lastline=4, frame=single]{PRESENTATION_ExAdv/red_or3x1_test.ys}
+\vskip-0.2cm\lstinputlisting[basicstyle=\ttfamily\fontsize{8pt}{10pt}\selectfont, language=verilog]{PRESENTATION_ExAdv/red_or3x1_test.v}
+\end{columns}
+\end{frame}
+
 \subsubsection{TBD}
 
 \begin{frame}{\subsubsecname}

manual/PRESENTATION_ExAdv/Makefile

@@ -1,6 +1,9 @@
 
-all: select_01.pdf
+all: select_01.pdf red_or3x1.pdf
 
 select_01.pdf: select_01.v select_01.ys
 	../../yosys select_01.ys
 
+red_or3x1.pdf: red_or3x1_*
+	../../yosys red_or3x1_test.ys
+

manual/PRESENTATION_ExAdv/red_or3x1_cells.v

@@ -0,0 +1,5 @@
+module OR3X1(A, B, C, Y);
+    input A, B, C;
+    output Y;
+    assign Y = A | B | C;
+endmodule

manual/PRESENTATION_ExAdv/red_or3x1_map.v

@@ -0,0 +1,48 @@
+module \$reduce_or (A, Y);
+
+    parameter A_SIGNED = 0;
+    parameter A_WIDTH = 0;
+    parameter Y_WIDTH = 0;
+    
+    input [A_WIDTH-1:0] A;
+    output [Y_WIDTH-1:0] Y;
+    
+    function integer min;
+        input integer a, b;
+        begin
+            if (a < b)
+                min = a;
+            else
+                min = b;
+        end
+    endfunction
+    
+    genvar i;
+    generate begin
+        if (A_WIDTH == 0) begin
+            assign Y = 0;
+        end
+        if (A_WIDTH == 1) begin
+            assign Y = A;
+        end
+        if (A_WIDTH == 2) begin
+            wire ybuf;
+            OR3X1 g (.A(A[0]), .B(A[1]), .C(1'b0), .Y(ybuf));
+            assign Y = ybuf;
+        end
+        if (A_WIDTH == 3) begin
+            wire ybuf;
+            OR3X1 g (.A(A[0]), .B(A[1]), .C(A[2]), .Y(ybuf));
+            assign Y = ybuf;
+        end
+        if (A_WIDTH > 3) begin
+            localparam next_stage_sz = (A_WIDTH+2) / 3;
+            wire [next_stage_sz-1:0] next_stage;
+            for (i = 0; i < next_stage_sz; i = i+1) begin
+                localparam bits = min(A_WIDTH - 3*i, 3);
+                assign next_stage[i] = |A[3*i +: bits];
+            end
+            assign Y = |next_stage;
+        end
+    end endgenerate
+endmodule

manual/PRESENTATION_ExAdv/red_or3x1_test.v

@@ -0,0 +1,5 @@
+module test (A, Y);
+    input [6:0] A;
+    output Y;
+    assign Y = |A;
+endmodule

manual/PRESENTATION_ExAdv/red_or3x1_test.ys

@@ -0,0 +1,7 @@
+read_verilog red_or3x1_test.v
+hierarchy -check -top test
+
+techmap -map red_or3x1_map.v;;
+
+splitnets -ports
+show -prefix red_or3x1 -format pdf -notitle -lib red_or3x1_cells.v