OpenCores
URL https://opencores.org/ocsvn/epc_rfid_transponder/epc_rfid_transponder/trunk

Subversion Repositories epc_rfid_transponder

[/] [epc_rfid_transponder/] [trunk/] [InvSelFlags.vhd] - Blame information for rev 3

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 erwing 
-------------------------------------------------------------------------------
2 
--     Politecnico di Torino
3 
--     Dipartimento di Automatica e Informatica
4 
-------------------------------------------------------------------------------
5 
-------------------------------------------------------------------------------
6 
--
7 
--     Title          : EPC Class1 Gen2 RFID Tag - Inventoried and Selected Flags Model
8 
--
9 
--     File name      : InvSelFlags.vhd
10 
--
11 
--     Description    : Simulation model of Inventoried and Selected Flags. It
12 
--                      includes persistence time as described in the EPC
13 
--                      standard v. 1.09.
14 
--
15 3 erwing 
--     Authors        : Erwing R. Sanchez <erwing.sanchez@polito.it>
16 2 erwing 
--
17 
-------------------------------------------------------------------------------
18 
-------------------------------------------------------------------------------
19 
 
20 
library IEEE;
21 
use IEEE.STD_LOGIC_1164.all;
22 
use IEEE.std_logic_unsigned.all;
23 
 
24 
 
25 
 
26 
entity InvSelFlag is
27 
  port (
28 
    S1i : in  std_logic;
29 
    S2i : in  std_logic;
30 
    S3i : in  std_logic;
31 
    SLi : in  std_logic;
32 
    S1o : out std_logic;
33 
    S2o : out std_logic;
34 
    S3o : out std_logic;
35 
    SLo : out std_logic);
36 
 
37 
end InvSelFlag;
38 
 
39 
 
40 
architecture Flags1 of InvSelFlag is
41 
-- synopsys synthesis_off
42 
  constant S1INV_PERSISTENCE_TIME : time := 500 ms;
43 
  constant S2INV_PERSISTENCE_TIME : time := 2 sec;
44 
  constant S3INV_PERSISTENCE_TIME : time := 2 sec;
45 
  constant SL_PERSISTENCE_TIME    : time := 2 sec;
46 
 
47 
  constant TM_STEP          : time      := 10 ns;
48 
  signal   S1_time_cnt      : time      := 1 ns;
49 
  signal   S2_time_cnt      : time      := 1 ns;
50 
  signal   S3_time_cnt      : time      := 1 ns;
51 
  signal   SL_time_cnt      : time      := 1 ns;
52 
  signal   S1_time_cnt_flag : std_logic := '0';
53 
  signal   S2_time_cnt_flag : std_logic := '0';
54 
  signal   S3_time_cnt_flag : std_logic := '0';
55 
  signal   SL_time_cnt_flag : std_logic := '0';
56 
 
57 
 
58 
 
59 
  -- synopsys synthesis_on
60 
begin  -- Flags1
61 
-- synopsys synthesis_off
62 
  S1FLAG : process (S1_time_cnt_flag, S1i)
63 
  begin  -- process S1FLAG
64 
    if S1i'event and (S1i = '0' or S1i = '1') then
65 
      S1o         <= S1i;
66 
      S1_time_cnt <= 0 ns after TM_STEP;
67 
    elsif S1_time_cnt_flag'event then
68 
      if S1_time_cnt = S1INV_PERSISTENCE_TIME then
69 
        S1o         <= 'X';
70 
        S1_time_cnt <= 0 ns after TM_STEP;
71 
      else
72 
        S1_time_cnt <= S1_time_cnt + TM_STEP after TM_STEP;
73 
      end if;
74 
    end if;
75 
  end process S1FLAG;
76 
 
77 
  S1FLAG_flag : process (S1_time_cnt)
78 
  begin  -- process S1FLAG_MIRROR
79 
    S1_time_cnt_flag <= not S1_time_cnt_flag;
80 
  end process S1FLAG_flag;
81 
 
82 
 
83 
  S2FLAG : process (S2_time_cnt_flag, S2i)
84 
  begin  -- process S2FLAG
85 
    if S2i'event and (S2i = '0' or S2i = '1') then
86 
      S2o         <= S2i;
87 
      S2_time_cnt <= 0 ns after TM_STEP;
88 
    elsif S2_time_cnt_flag'event then
89 
      if S2_time_cnt = S2INV_PERSISTENCE_TIME then
90 
        S2o         <= 'X';
91 
        S2_time_cnt <= 0 ns after TM_STEP;
92 
      else
93 
        S2_time_cnt <= S2_time_cnt + TM_STEP after TM_STEP;
94 
      end if;
95 
    end if;
96 
  end process S2FLAG;
97 
 
98 
  S2FLAG_flag : process (S2_time_cnt)
99 
  begin  -- process S2FLAG_MIRROR
100 
    S2_time_cnt_flag <= not S2_time_cnt_flag;
101 
  end process S2FLAG_flag;
102 
 
103 
  S3FLAG : process (S3_time_cnt_flag, S3i)
104 
  begin  -- process S3FLAG
105 
    if S3i'event and (S3i = '0' or S3i = '1') then
106 
      S3o         <= S3i;
107 
      S3_time_cnt <= 0 ns after TM_STEP;
108 
    elsif S3_time_cnt_flag'event then
109 
      if S3_time_cnt = S3INV_PERSISTENCE_TIME then
110 
        S3o         <= 'X';
111 
        S3_time_cnt <= 0 ns after TM_STEP;
112 
      else
113 
        S3_time_cnt <= S3_time_cnt + TM_STEP after TM_STEP;
114 
      end if;
115 
    end if;
116 
  end process S3FLAG;
117 
 
118 
  S3FLAG_flag : process (S3_time_cnt)
119 
  begin  -- process S3FLAG_MIRROR
120 
    S3_time_cnt_flag <= not S3_time_cnt_flag;
121 
  end process S3FLAG_flag;
122 
 
123 
  SLFLAG : process (SL_time_cnt_flag, SLi)
124 
  begin  -- process SLFLAG
125 
    if SLi'event and (SLi = '0' or SLi = '1') then
126 
      SLo         <= SLi;
127 
      SL_time_cnt <= 0 ns after TM_STEP;
128 
    elsif SL_time_cnt_flag'event then
129 
      if SL_time_cnt = SL_PERSISTENCE_TIME then
130 
        SLo         <= 'X';
131 
        SL_time_cnt <= 0 ns after TM_STEP;
132 
      else
133 
        SL_time_cnt <= SL_time_cnt + TM_STEP after TM_STEP;
134 
      end if;
135 
    end if;
136 
  end process SLFLAG;
137 
 
138 
  SLFLAG_flag : process (SL_time_cnt)
139 
  begin  -- process SLFLAG_MIRROR
140 
    SL_time_cnt_flag <= not SL_time_cnt_flag;
141 
  end process SLFLAG_flag;
142 
-- synopsys synthesis_on
143 
end Flags1;

powered by: WebSVN 2.1.0

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