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[/] [adder/] [trunk/] [high-speed-adder-128bits-opencore.v] - Rev 5
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///////////////////////////////////////////////////////////////////// //// //// //// High Speed Adder for Large Bitsize Computation (128 Bits) //// //// //// //// Authors: seanlee (seanlee@opencores.org) //// //// //// //// http://www.opencores.org/projects/adder //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2005 Sean Lee //// //// seanlee@opencores.org //// //// //// //// This source file may be used and distributed without //// //// restriction provided that this copyright statement is not //// //// removed from the file and that any derivative work contains //// //// the original copyright notice and the associated disclaimer.//// //// //// //// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// //// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// //// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// //// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// //// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// //// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// //// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// //// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// //// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// //// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// //// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// //// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// //// POSSIBILITY OF SUCH DAMAGE. //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Note: The verilog file is written based on 128 bits. //// //// The 128 bits adder was tested on a 0.35 //// //// micron technology and synthesis results yielded a 18% //// //// speed improvement over conventional carry look ahead adder //// //// and 85% improvement compared to conventional ripple adder. //// //// //// //// The verilog code can be expanded using the same concept //// //// for 256 bits, 512 bits or beyond. //// ///////////////////////////////////////////////////////////////////// module adder_128bit (A, B, Sum); input [127:0] A,B; output [128:0] Sum; wire [128:0] Sum; wire [8:0] tempSum1, tempSum2, tempSum3, tempSum4, tempSum5, tempSum6, tempSum7, tempSum8; wire [8:0] tempSum9, tempSum10, tempSum11, tempSum12, tempSum13, tempSum14, tempSum15, tempSum16; wire tempCarry1, tempCarry2, tempCarry3, tempCarry4, tempCarry5, tempCarry6, tempCarry7, tempCarry8; wire tempCarry9, tempCarry10, tempCarry11, tempCarry12, tempCarry13, tempCarry14, tempCarry15, tempCarry16; wire f2, f3, f4, f5, f6, f7, f8; wire f9, f10, f11, f12, f13, f14, f15, f16; wire c1, c2, c3, c4, c5, c6, c7, c8; wire c9, c10, c11, c12, c13, c14, c15, c16; assign tempSum1 = A[7:0] + B[7:0]; assign tempSum2 = A[15:8] + B[15:8]; assign tempSum3 = A[23:16] + B[23:16]; assign tempSum4 = A[31:24] + B[31:24]; assign tempSum5 = A[39:32] + B[39:32]; assign tempSum6 = A[47:40] + B[47:40]; assign tempSum7 = A[55:48] + B[55:48]; assign tempSum8 = A[63:56] + B[63:56]; assign tempSum9 = A[71:64] + B[71:64]; assign tempSum10 = A[79:72] + B[79:72]; assign tempSum11 = A[87:80] + B[87:80]; assign tempSum12 = A[95:88] + B[95:88]; assign tempSum13 = A[103:96] + B[103:96]; assign tempSum14 = A[111:104] + B[111:104]; assign tempSum15 = A[119:112] + B[119:112]; assign tempSum16 = A[127:120] + B[127:120]; assign tempCarry1 = tempSum1[8]; assign tempCarry2 = tempSum2[8]; assign tempCarry3 = tempSum3[8]; assign tempCarry4 = tempSum4[8]; assign tempCarry5 = tempSum5[8]; assign tempCarry6 = tempSum6[8]; assign tempCarry7 = tempSum7[8]; assign tempCarry8 = tempSum8[8]; assign tempCarry9 = tempSum9[8]; assign tempCarry10 = tempSum10[8]; assign tempCarry11 = tempSum11[8]; assign tempCarry12 = tempSum12[8]; assign tempCarry13 = tempSum13[8]; assign tempCarry14 = tempSum14[8]; assign tempCarry15 = tempSum15[8]; assign tempCarry16 = tempSum16[8]; assign f2 = (tempSum2[7:0] == 8'hff); assign f3 = (tempSum3[7:0] == 8'hff); assign f4 = (tempSum4[7:0] == 8'hff); assign f5 = (tempSum5[7:0] == 8'hff); assign f6 = (tempSum6[7:0] == 8'hff); assign f7 = (tempSum7[7:0] == 8'hff); assign f8 = (tempSum8[7:0] == 8'hff); assign f9 = (tempSum9[7:0] == 8'hff); assign f10 = (tempSum10[7:0] == 8'hff); assign f11 = (tempSum11[7:0] == 8'hff); assign f12 = (tempSum12[7:0] == 8'hff); assign f13 = (tempSum13[7:0] == 8'hff); assign f14 = (tempSum14[7:0] == 8'hff); assign f15 = (tempSum15[7:0] == 8'hff); assign f16 = (tempSum16[7:0] == 8'hff); assign c1 = tempCarry1; assign c2 = (c1 & f2) | tempCarry2; assign c3 = (c2 & f3) | tempCarry3; assign c4 = (c3 & f4) | tempCarry4; assign c5 = (c4 & f5) | tempCarry5; assign c6 = (c5 & f6) | tempCarry6; assign c7 = (c6 & f7) | tempCarry7; assign c8 = (c7 & f8) | tempCarry8; assign c9 = (c8 & f9) | tempCarry9; assign c10 = (c9 & f10) | tempCarry10; assign c11 = (c10 & f11) | tempCarry11; assign c12 = (c11 & f12) | tempCarry12; assign c13 = (c12 & f13) | tempCarry13; assign c14 = (c13 & f14) | tempCarry14; assign c15 = (c14 & f15) | tempCarry15; assign c16 = (c15 & f16) | tempCarry16; assign Sum[7:0] = tempSum1[7:0]; assign Sum[15:8] = c1 ? (tempSum2[7:0] + 1) : tempSum2[7:0]; assign Sum[23:16] = c2 ? (tempSum3[7:0] + 1) : tempSum3[7:0]; assign Sum[31:24] = c3 ? (tempSum4[7:0] + 1) : tempSum4[7:0]; assign Sum[39:32] = c4 ? (tempSum5[7:0] + 1) : tempSum5[7:0]; assign Sum[47:40] = c5 ? (tempSum6[7:0] + 1) : tempSum6[7:0]; assign Sum[55:48] = c6 ? (tempSum7[7:0] + 1) : tempSum7[7:0]; assign Sum[63:56] = c7 ? (tempSum8[7:0] + 1) : tempSum8[7:0]; assign Sum[71:64] = c8 ? (tempSum9[7:0] + 1) : tempSum9[7:0]; assign Sum[79:72] = c9 ? (tempSum10[7:0] + 1) : tempSum10[7:0]; assign Sum[87:80] = c10 ? (tempSum11[7:0] + 1) : tempSum11[7:0]; assign Sum[95:88] = c11 ? (tempSum12[7:0] + 1) : tempSum12[7:0]; assign Sum[103:96] = c12 ? (tempSum13[7:0] + 1) : tempSum13[7:0]; assign Sum[111:104] = c13 ? (tempSum14[7:0] + 1) : tempSum14[7:0]; assign Sum[119:112] = c14 ? (tempSum15[7:0] + 1) : tempSum15[7:0]; assign Sum[127:120] = c15 ? (tempSum16[7:0] + 1) : tempSum16[7:0]; assign Sum[128] = c16; endmodule