yosys/techlibs/common/techmap.v

466 lines
12 KiB
Verilog

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* ---
*
* The internal logic cell technology mapper.
*
* This verilog library contains the mapping of internal cells (e.g. $not with
* variable bit width) to the internal logic cells (such as the single bit $_NOT_
* gate). Usually this logic network is then mapped to the actual technology
* using e.g. the "abc" pass.
*
* Note that this library does not map $mem cells. They must be mapped to logic
* and $dff cells using the "memory_map" pass first. (Or map it to custom cells,
* which is of course highly recommended for larger memories.)
*
*/
`define MIN(_a, _b) ((_a) < (_b) ? (_a) : (_b))
`define MAX(_a, _b) ((_a) > (_b) ? (_a) : (_b))
// --------------------------------------------------------
// Use simplemap for trivial cell types
// --------------------------------------------------------
(* techmap_simplemap *)
(* techmap_celltype = "$not $and $or $xor $xnor" *)
module _90_simplemap_bool_ops;
endmodule
(* techmap_simplemap *)
(* techmap_celltype = "$reduce_and $reduce_or $reduce_xor $reduce_xnor $reduce_bool" *)
module _90_simplemap_reduce_ops;
endmodule
(* techmap_simplemap *)
(* techmap_celltype = "$logic_not $logic_and $logic_or" *)
module _90_simplemap_logic_ops;
endmodule
(* techmap_simplemap *)
(* techmap_celltype = "$eq $eqx $ne $nex" *)
module _90_simplemap_compare_ops;
endmodule
(* techmap_simplemap *)
(* techmap_celltype = "$pos $slice $concat $mux" *)
module _90_simplemap_various;
endmodule
(* techmap_simplemap *)
(* techmap_celltype = "$sr $dff $dffe $adff $dffsr $dlatch" *)
module _90_simplemap_registers;
endmodule
// --------------------------------------------------------
// Shift operators
// --------------------------------------------------------
(* techmap_celltype = "$shr $shl $sshl $sshr" *)
module _90_shift_ops_shr_shl_sshl_sshr (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
parameter _TECHMAP_CELLTYPE_ = "";
localparam shift_left = _TECHMAP_CELLTYPE_ == "$shl" || _TECHMAP_CELLTYPE_ == "$sshl";
localparam sign_extend = A_SIGNED && _TECHMAP_CELLTYPE_ == "$sshr";
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
localparam WIDTH = `MAX(A_WIDTH, Y_WIDTH);
localparam BB_WIDTH = `MIN($clog2(shift_left ? Y_WIDTH : A_SIGNED ? WIDTH : A_WIDTH) + 1, B_WIDTH);
wire [1023:0] _TECHMAP_DO_00_ = "proc;;";
wire [1023:0] _TECHMAP_DO_01_ = "RECURSION; CONSTMAP; opt_muxtree; opt_const -mux_undef -mux_bool -fine;;;";
integer i;
reg [WIDTH-1:0] buffer;
reg overflow;
always @* begin
overflow = B_WIDTH > BB_WIDTH ? |B[B_WIDTH-1:BB_WIDTH] : 1'b0;
buffer = overflow ? {WIDTH{sign_extend ? A[A_WIDTH-1] : 1'b0}} : {{WIDTH-A_WIDTH{A_SIGNED ? A[A_WIDTH-1] : 1'b0}}, A};
for (i = 0; i < BB_WIDTH; i = i+1)
if (B[i]) begin
if (shift_left)
buffer = {buffer, (2**i)'b0};
else if (2**i < WIDTH)
buffer = {{2**i{sign_extend ? buffer[WIDTH-1] : 1'b0}}, buffer[WIDTH-1 : 2**i]};
else
buffer = {WIDTH{sign_extend ? buffer[WIDTH-1] : 1'b0}};
end
end
assign Y = buffer;
endmodule
(* techmap_celltype = "$shift $shiftx" *)
module _90_shift_shiftx (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
localparam BB_WIDTH = `MIN($clog2(`MAX(A_WIDTH, Y_WIDTH)) + (B_SIGNED ? 2 : 1), B_WIDTH);
localparam WIDTH = `MAX(A_WIDTH, Y_WIDTH) + (B_SIGNED ? 2**(BB_WIDTH-1) : 0);
parameter _TECHMAP_CELLTYPE_ = "";
localparam extbit = _TECHMAP_CELLTYPE_ == "$shift" ? 1'b0 : 1'bx;
wire [1023:0] _TECHMAP_DO_00_ = "proc;;";
wire [1023:0] _TECHMAP_DO_01_ = "CONSTMAP; opt_muxtree; opt_const -mux_undef -mux_bool -fine;;;";
integer i;
reg [WIDTH-1:0] buffer;
reg overflow;
always @* begin
overflow = 0;
buffer = {WIDTH{extbit}};
buffer[`MAX(A_WIDTH, Y_WIDTH)-1:0] = A;
if (B_WIDTH > BB_WIDTH) begin
if (B_SIGNED) begin
for (i = BB_WIDTH; i < B_WIDTH; i = i+1)
if (B[i] != B[BB_WIDTH-1])
overflow = 1;
end else
overflow = |B[B_WIDTH-1:BB_WIDTH];
if (overflow)
buffer = {WIDTH{extbit}};
end
for (i = BB_WIDTH-1; i >= 0; i = i-1)
if (B[i]) begin
if (B_SIGNED && i == BB_WIDTH-1)
buffer = {buffer, {2**i{extbit}}};
else if (2**i < WIDTH)
buffer = {{2**i{extbit}}, buffer[WIDTH-1 : 2**i]};
else
buffer = {WIDTH{extbit}};
end
end
assign Y = buffer;
endmodule
// --------------------------------------------------------
// Arithmetic operators
// --------------------------------------------------------
(* techmap_celltype = "$fa" *)
module _90_fa (A, B, C, X, Y);
parameter WIDTH = 1;
input [WIDTH-1:0] A, B, C;
output [WIDTH-1:0] X, Y;
wire [WIDTH-1:0] t1, t2, t3;
assign t1 = A ^ B, t2 = A & B, t3 = C & t1;
assign Y = t1 ^ C, X = t2 | t3;
endmodule
(* techmap_celltype = "$lcu" *)
module _90_lcu (P, G, CI, CO);
parameter WIDTH = 2;
input [WIDTH-1:0] P, G;
input CI;
output [WIDTH-1:0] CO;
integer i, j;
reg [WIDTH-1:0] p, g;
wire [1023:0] _TECHMAP_DO_ = "proc; opt -fast";
always @* begin
p = P;
g = G;
// in almost all cases CI will be constant zero
g[0] = g[0] | (p[0] & CI);
// [[CITE]] Brent Kung Adder
// R. P. Brent and H. T. Kung, "A Regular Layout for Parallel Adders",
// IEEE Transaction on Computers, Vol. C-31, No. 3, p. 260-264, March, 1982
// Main tree
for (i = 1; i <= $clog2(WIDTH); i = i+1) begin
for (j = 2**i - 1; j < WIDTH; j = j + 2**i) begin
g[j] = g[j] | p[j] & g[j - 2**(i-1)];
p[j] = p[j] & p[j - 2**(i-1)];
end
end
// Inverse tree
for (i = $clog2(WIDTH); i > 0; i = i-1) begin
for (j = 2**i + 2**(i-1) - 1; j < WIDTH; j = j + 2**i) begin
g[j] = g[j] | p[j] & g[j - 2**(i-1)];
p[j] = p[j] & p[j - 2**(i-1)];
end
end
end
assign CO = g;
endmodule
(* techmap_celltype = "$alu" *)
module _90_alu (A, B, CI, BI, X, Y, CO);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] X, Y;
input CI, BI;
output [Y_WIDTH-1:0] CO;
wire [Y_WIDTH-1:0] A_buf, B_buf;
\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
wire [Y_WIDTH-1:0] AA = A_buf;
wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf;
\$lcu #(.WIDTH(Y_WIDTH)) lcu (.P(X), .G(AA & BB), .CI(CI), .CO(CO));
assign X = AA ^ BB;
assign Y = X ^ {CO, CI};
endmodule
(* techmap_maccmap *)
(* techmap_celltype = "$macc" *)
module _90_macc;
endmodule
(* techmap_wrap = "alumacc" *)
(* techmap_celltype = "$lt $le $ge $gt $add $sub $neg $mul" *)
module _90_alumacc;
endmodule
// --------------------------------------------------------
// Divide and Modulo
// --------------------------------------------------------
module \$__div_mod_u (A, B, Y, R);
parameter WIDTH = 1;
input [WIDTH-1:0] A, B;
output [WIDTH-1:0] Y, R;
wire [WIDTH*WIDTH-1:0] chaindata;
assign R = chaindata[WIDTH*WIDTH-1:WIDTH*(WIDTH-1)];
genvar i;
generate begin
for (i = 0; i < WIDTH; i=i+1) begin:stage
wire [WIDTH-1:0] stage_in;
if (i == 0) begin:cp
assign stage_in = A;
end else begin:cp
assign stage_in = chaindata[i*WIDTH-1:(i-1)*WIDTH];
end
assign Y[WIDTH-(i+1)] = stage_in >= {B, {WIDTH-(i+1){1'b0}}};
assign chaindata[(i+1)*WIDTH-1:i*WIDTH] = Y[WIDTH-(i+1)] ? stage_in - {B, {WIDTH-(i+1){1'b0}}} : stage_in;
end
end endgenerate
endmodule
module \$__div_mod (A, B, Y, R);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
localparam WIDTH =
A_WIDTH >= B_WIDTH && A_WIDTH >= Y_WIDTH ? A_WIDTH :
B_WIDTH >= A_WIDTH && B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y, R;
wire [WIDTH-1:0] A_buf, B_buf;
\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(WIDTH)) A_conv (.A(A), .Y(A_buf));
\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(WIDTH)) B_conv (.A(B), .Y(B_buf));
wire [WIDTH-1:0] A_buf_u, B_buf_u, Y_u, R_u;
assign A_buf_u = A_SIGNED && A_buf[WIDTH-1] ? -A_buf : A_buf;
assign B_buf_u = B_SIGNED && B_buf[WIDTH-1] ? -B_buf : B_buf;
\$__div_mod_u #(
.WIDTH(WIDTH)
) div_mod_u (
.A(A_buf_u),
.B(B_buf_u),
.Y(Y_u),
.R(R_u)
);
assign Y = A_SIGNED && B_SIGNED && (A_buf[WIDTH-1] != B_buf[WIDTH-1]) ? -Y_u : Y_u;
assign R = A_SIGNED && B_SIGNED && A_buf[WIDTH-1] ? -R_u : R_u;
endmodule
(* techmap_celltype = "$div" *)
module _90_div (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
\$__div_mod #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(Y_WIDTH)
) div_mod (
.A(A),
.B(B),
.Y(Y)
);
endmodule
(* techmap_celltype = "$mod" *)
module _90_mod (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
\$__div_mod #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
.B_WIDTH(B_WIDTH),
.Y_WIDTH(Y_WIDTH)
) div_mod (
.A(A),
.B(B),
.R(Y)
);
endmodule
// --------------------------------------------------------
// Power
// --------------------------------------------------------
(* techmap_celltype = "$pow" *)
module _90_pow (A, B, Y);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
parameter B_WIDTH = 1;
parameter Y_WIDTH = 1;
input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B;
output [Y_WIDTH-1:0] Y;
wire _TECHMAP_FAIL_ = 1;
endmodule
// --------------------------------------------------------
// Parallel Multiplexers
// --------------------------------------------------------
(* techmap_celltype = "$pmux" *)
module _90_pmux (A, B, S, Y);
parameter WIDTH = 1;
parameter S_WIDTH = 1;
input [WIDTH-1:0] A;
input [WIDTH*S_WIDTH-1:0] B;
input [S_WIDTH-1:0] S;
output [WIDTH-1:0] Y;
wire [WIDTH-1:0] Y_B;
genvar i, j;
generate
wire [WIDTH*S_WIDTH-1:0] B_AND_S;
for (i = 0; i < S_WIDTH; i = i + 1) begin:B_AND
assign B_AND_S[WIDTH*(i+1)-1:WIDTH*i] = B[WIDTH*(i+1)-1:WIDTH*i] & {WIDTH{S[i]}};
end:B_AND
for (i = 0; i < WIDTH; i = i + 1) begin:B_OR
wire [S_WIDTH-1:0] B_AND_BITS;
for (j = 0; j < S_WIDTH; j = j + 1) begin:B_AND_BITS_COLLECT
assign B_AND_BITS[j] = B_AND_S[WIDTH*j+i];
end:B_AND_BITS_COLLECT
assign Y_B[i] = |B_AND_BITS;
end:B_OR
endgenerate
assign Y = |S ? Y_B : A;
endmodule
// --------------------------------------------------------
// LUTs
// --------------------------------------------------------
`ifndef NOLUT
(* techmap_celltype = "$lut" *)
module _90_lut (A, Y);
parameter WIDTH = 1;
parameter LUT = 0;
input [WIDTH-1:0] A;
output Y;
assign Y = LUT[A];
endmodule
`endif