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| author | Eddie Hung <eddie@fpgeh.com> | 2019-08-09 12:33:39 -0700 | 
|---|---|---|
| committer | Eddie Hung <eddie@fpgeh.com> | 2019-08-09 12:33:39 -0700 | 
| commit | 041defc5a60f702c8f6089a91d7c8679c751014b (patch) | |
| tree | 66bfaa0cd0632befa8fea6a94ee78b47dae8c0e7 /techlibs/common | |
| parent | acfb672d34092d67b0b3ed6a6ab45e5aac8e2bc0 (diff) | |
| download | yosys-041defc5a60f702c8f6089a91d7c8679c751014b.tar.gz yosys-041defc5a60f702c8f6089a91d7c8679c751014b.tar.bz2 yosys-041defc5a60f702c8f6089a91d7c8679c751014b.zip | |
Reformat so it shows up/looks nice when "help $alu" and "help $alu+"
Diffstat (limited to 'techlibs/common')
| -rw-r--r-- | techlibs/common/simlib.v | 59 | 
1 files changed, 34 insertions, 25 deletions
| diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v index 1b172c112..7845a3fed 100644 --- a/techlibs/common/simlib.v +++ b/techlibs/common/simlib.v @@ -532,20 +532,24 @@ endmodule  // -------------------------------------------------------- -// Lookahead carry unit -//   A building block dedicated to fast computation of carry-bits -//   used in binary arithmetic operations. By replacing the ripple -//   carry structure used in full-adder blocks, the more significant -//   bits of the sum can be expected to be computed more quickly. -//   Typically created during `techmap` of $alu cells -//   (see the "_90_alu" rule in +/techmap.v) +//  |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//-     $lcu (P, G, CI, CO) +//- +//- Lookahead carry unit +//- A building block dedicated to fast computation of carry-bits used in binary +//- arithmetic operations. By replacing the ripple carry structure used in full-adder +//- blocks, the more significant  bits of the sum can be expected to be computed more +//- quickly. +//- Typically created during `techmap` of $alu cells (see the "_90_alu" rule in +//- +/techmap.v).  module \$lcu (P, G, CI, CO);  parameter WIDTH = 1; -input [WIDTH-1:0] P;	// Propagate -input [WIDTH-1:0] G;	// Generate -input CI;		// Carry-in +input [WIDTH-1:0] P;    // Propagate +input [WIDTH-1:0] G;    // Generate +input CI;               // Carry-in  output reg [WIDTH-1:0] CO; // Carry-out @@ -563,12 +567,17 @@ endmodule  // -------------------------------------------------------- -// Arithmetic logic unit -//   A building block supporting both binary addition/subtraction -//   operations, and indirectly, comparison operations. -//   Typically created by the `alumacc` pass, which transforms -//   $add, $sub, $lt, $le, $ge, $gt, $eq, $eqx, $ne, $nex -//   cells into this $alu cell. +//  |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//-     $alu (A, B, CI, BI, X, Y, CO) +//- +//- Arithmetic logic unit. +//- A building block supporting both binary addition/subtraction operations, and +//- indirectly, comparison operations. +//- Typically created by the `alumacc` pass, which transforms: +//-   $add, $sub, $lt, $le, $ge, $gt, $eq, $eqx, $ne, $nex +//- cells into this $alu cell. +//-  module \$alu (A, B, CI, BI, X, Y, CO);  parameter A_SIGNED = 0; @@ -577,16 +586,16 @@ parameter A_WIDTH = 1;  parameter B_WIDTH = 1;  parameter Y_WIDTH = 1; -input [A_WIDTH-1:0] A;		// Input operand -input [B_WIDTH-1:0] B;		// Input operand -output [Y_WIDTH-1:0] X;		// A xor B (sign-extended, optional B inversion, -				//          used in combination with -				//          reduction-AND for $eq/$ne ops) -output [Y_WIDTH-1:0] Y;		// Sum +input [A_WIDTH-1:0] A;      // Input operand +input [B_WIDTH-1:0] B;      // Input operand +output [Y_WIDTH-1:0] X;     // A xor B (sign-extended, optional B inversion, +                            //          used in combination with +                            //          reduction-AND for $eq/$ne ops) +output [Y_WIDTH-1:0] Y;     // Sum -input CI;			// Carry-in (set for $sub) -input BI;			// Invert-B (set for $sub) -output [Y_WIDTH-1:0] CO;	// Carry-out +input CI;                   // Carry-in (set for $sub) +input BI;                   // Invert-B (set for $sub) +output [Y_WIDTH-1:0] CO;    // Carry-out  wire [Y_WIDTH-1:0] AA, BB; | 
