OpenCores
URL https://opencores.org/ocsvn/an-fpga-implementation-of-low-latency-noc-based-mpsoc/an-fpga-implementation-of-low-latency-noc-based-mpsoc/trunk

Subversion Repositories an-fpga-implementation-of-low-latency-noc-based-mpsoc

[/] [an-fpga-implementation-of-low-latency-noc-based-mpsoc/] [trunk/] [mpsoc/] [src_processor/] [new_lm32/] [rtl/] [lm32_adder.v] - Blame information for rev 48

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 48 alirezamon 
//   ==================================================================
2 
//   >>>>>>>>>>>>>>>>>>>>>>> COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<
3 
//   ------------------------------------------------------------------
4 
//   Copyright (c) 2006-2011 by Lattice Semiconductor Corporation
5 
//   ALL RIGHTS RESERVED
6 
//   ------------------------------------------------------------------
7 
//
8 
//   IMPORTANT: THIS FILE IS AUTO-GENERATED BY THE LATTICEMICO SYSTEM.
9 
//
10 
//   Permission:
11 
//
12 
//      Lattice Semiconductor grants permission to use this code
13 
//      pursuant to the terms of the Lattice Semiconductor Corporation
14 
//      Open Source License Agreement.
15 
//
16 
//   Disclaimer:
17 
//
18 
//      Lattice Semiconductor provides no warranty regarding the use or
19 
//      functionality of this code. It is the user's responsibility to
20 
//      verify the user's design for consistency and functionality through
21 
//      the use of formal verification methods.
22 
//
23 
//   --------------------------------------------------------------------
24 
//
25 
//                  Lattice Semiconductor Corporation
26 
//                  5555 NE Moore Court
27 
//                  Hillsboro, OR 97214
28 
//                  U.S.A
29 
//
30 
//                  TEL: 1-800-Lattice (USA and Canada)
31 
//                         503-286-8001 (other locations)
32 
//
33 
//                  web: http://www.latticesemi.com/
34 
//                  email: techsupport@latticesemi.com
35 
//
36 
//   --------------------------------------------------------------------
37 
//                         FILE DETAILS
38 
// Project          : LatticeMico32
39 
// File             : lm32_adder.v
40 
// Title            : Integer adder / subtractor with comparison flag generation
41 
// Dependencies     : lm32_include.v
42 
// Version          : 6.1.17
43 
//                  : Initial Release
44 
// Version          : 7.0SP2, 3.0
45 
//                  : No Change
46 
// Version          : 3.1
47 
//                  : No Change
48 
// =============================================================================
49 
 
50 
`include "lm32_include.v"
51 
 
52 
/////////////////////////////////////////////////////
53 
// Module interface
54 
/////////////////////////////////////////////////////
55 
 
56 
module lm32_adder (
57 
    // ----- Inputs -------
58 
    adder_op_x,
59 
    adder_op_x_n,
60 
    operand_0_x,
61 
    operand_1_x,
62 
    // ----- Outputs -------
63 
    adder_result_x,
64 
    adder_carry_n_x,
65 
    adder_overflow_x
66 
    );
67 
 
68 
/////////////////////////////////////////////////////
69 
// Inputs
70 
/////////////////////////////////////////////////////
71 
 
72 
input adder_op_x;                                       // Operating to perform, 0 for addition, 1 for subtraction
73 
input adder_op_x_n;                                     // Inverted version of adder_op_x
74 
input [`LM32_WORD_RNG] operand_0_x;                     // Operand to add, or subtract from
75 
input [`LM32_WORD_RNG] operand_1_x;                     // Opearnd to add, or subtract by
76 
 
77 
/////////////////////////////////////////////////////
78 
// Outputs
79 
/////////////////////////////////////////////////////
80 
 
81 
output [`LM32_WORD_RNG] adder_result_x;                 // Result of addition or subtraction
82 
wire   [`LM32_WORD_RNG] adder_result_x;
83 
output adder_carry_n_x;                                 // Inverted carry
84 
wire   adder_carry_n_x;
85 
output adder_overflow_x;                                // Indicates if overflow occured, only valid for subtractions
86 
reg    adder_overflow_x;
87 
 
88 
/////////////////////////////////////////////////////
89 
// Internal nets and registers
90 
/////////////////////////////////////////////////////
91 
 
92 
wire a_sign;                                            // Sign (i.e. positive or negative) of operand 0
93 
wire b_sign;                                            // Sign of operand 1
94 
wire result_sign;                                       // Sign of result
95 
 
96 
/////////////////////////////////////////////////////
97 
// Instantiations
98 
/////////////////////////////////////////////////////
99 
 
100 
lm32_addsub addsub (
101 
    // ----- Inputs -----
102 
    .DataA          (operand_0_x),
103 
    .DataB          (operand_1_x),
104 
    .Cin            (adder_op_x),
105 
    .Add_Sub        (adder_op_x_n),
106 
    // ----- Ouputs -----
107 
    .Result         (adder_result_x),
108 
    .Cout           (adder_carry_n_x)
109 
    );
110 
 
111 
/////////////////////////////////////////////////////
112 
// Combinational Logic
113 
/////////////////////////////////////////////////////
114 
 
115 
// Extract signs of operands and result
116 
 
117 
assign a_sign = operand_0_x[`LM32_WORD_WIDTH-1];
118 
assign b_sign = operand_1_x[`LM32_WORD_WIDTH-1];
119 
assign result_sign = adder_result_x[`LM32_WORD_WIDTH-1];
120 
 
121 
// Determine whether an overflow occured when performing a subtraction
122 
 
123 
always @(*)
124 
begin
125 
    //  +ve - -ve = -ve -> overflow
126 
    //  -ve - +ve = +ve -> overflow
127 
    if  (   (!a_sign & b_sign & result_sign)
128 
         || (a_sign & !b_sign & !result_sign)
129 
        )
130 
        adder_overflow_x = `TRUE;
131 
    else
132 
        adder_overflow_x = `FALSE;
133 
end
134 
 
135 
endmodule
136 
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.