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[/] [i2c_to_wb/] [trunk/] [sim/] [models/] [i2c_master_model.v] - Blame information for rev 2

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// --------------------------------------------------------------------
//
// --------------------------------------------------------------------
 
`timescale 1ns/10ps
 
 
module
  i2c_master_model
  #(
    parameter LOG_LEVEL = 3
  )
  (
    inout i2c_data,
    inout i2c_clk
  );
 
  localparam tBUF     = 4700;
  localparam tSU_STA  = 4700;
  localparam tSU_DAT  = 250;
  localparam tHD_DAT  = 0;
  localparam tHD_STA  = 4000;
  localparam tLOW     = 4700;
  localparam tHIGH    = 4000;
 
  // --------------------------------------------------------------------
  //  wires & regs
  wire i2c_data_in = i2c_data;
  wire i2c_clk_in  = i2c_clk;
 
  reg i2c_data_oe;
  reg i2c_clk_oe;
  reg i2c_data_out;
  reg i2c_clk_out;
 
  reg i2c_ack_in;
 
 
  // --------------------------------------------------------------------
  //  init 
  initial
    begin
      i2c_data_oe   = 1'b0;
      i2c_clk_oe    = 1'b0;
      i2c_data_out  = 1'b1;
      i2c_clk_out   = 1'b1;
    end
 
 
  // --------------------------------------------------------------------
  //  start
  task start;
    begin
 
      if( LOG_LEVEL > 2 )
        $display( "###- %m: I2C start at time %t. ", $time );
 
      i2c_data_out  = 1'b1;
      i2c_clk_out   = 1'b1;
 
      #tBUF;
 
      i2c_data_oe = 1'b1;
      i2c_clk_oe  = 1'b1;
 
      if( i2c_data != 1'b1 )
        begin
          #tHD_DAT;
          i2c_data_out = 1'b1;
        end
 
      if( i2c_clk != 1'b1 )
        begin
          i2c_clk_out = 1'b1;
          #tSU_DAT;
        end
 
      #tSU_STA;
      i2c_data_out = 1'b0;
 
    end
  endtask
 
 
  // --------------------------------------------------------------------
  //  stop
  task stop;
    begin
 
      if( LOG_LEVEL > 2 )
        $display( "###- %m: I2C stop at time %t. ", $time );
 
      if( i2c_data != 1'b0 )
        begin
          #tHD_DAT;
          i2c_data_out = 1'b0;
        end
 
      if( i2c_clk != 1'b1 )
        begin
          i2c_clk_out = 1'b1;
          #tSU_DAT;
        end
 
      i2c_data_out  = 1'b1;
      i2c_clk_out   = 1'b1;
 
      i2c_data_oe = 1'b0;
      i2c_clk_oe  = 1'b0;
 
    end
  endtask
 
 
  // --------------------------------------------------------------------
  //  write_bit
  task write_bit;
    input bit;
      begin
 
        #tHD_DAT;
        i2c_data_oe = 1'b1;
        i2c_data_out = bit;
        #tLOW;
 
        i2c_clk_out = 1'b1;
        #tHIGH;
        i2c_clk_out = 1'b0;
 
 
      end
  endtask
 
 
  // --------------------------------------------------------------------
  //  write_byte
  task write_byte;
    input [7:0]  data;
      begin
 
        if( LOG_LEVEL > 2 )
          $display( "###- %m: I2C write 0x%h at time %t. ", data, $time );
 
        #tHD_STA;
 
        i2c_clk_out = 1'b0;
 
        write_bit( data[7] );
        write_bit( data[6] );
        write_bit( data[5] );
        write_bit( data[4] );
        write_bit( data[3] );
        write_bit( data[2] );
        write_bit( data[1] );
        write_bit( data[0] );
 
        #tHD_DAT;
        i2c_data_oe = 1'b0;
        #tLOW;
 
        i2c_clk_out = 1'b1;
 
        i2c_ack_in = i2c_data;
 
        if( LOG_LEVEL > 2 )
          if( i2c_data )
            $display( "###- %m: I2C NACK at time %t. ", $time );
          else
            $display( "###- %m: I2C ACK at time %t. ", $time );
 
        #tHIGH;
 
      end
  endtask
 
 
  // --------------------------------------------------------------------
  //  read_bit
  reg [7:0] i2c_buffer_in;
 
  task read_bit;
    input [3:0] bit;
      begin
 
        i2c_data_oe = 1'b0;
 
        #tHD_DAT;
        i2c_buffer_in[bit] = i2c_data_in;
        #tLOW;
 
        i2c_clk_out = 1'b1;
        #tHIGH;
        i2c_clk_out = 1'b0;
 
 
      end
  endtask
 
 
  // --------------------------------------------------------------------
  //  read_byte
  task read_byte;
      begin
 
        #tHD_STA;
 
        i2c_clk_out = 1'b0;
        i2c_data_oe = 1'b0;
 
        read_bit( 7 );
        read_bit( 6 );
        read_bit( 5 );
        read_bit( 4 );
        read_bit( 3 );
        read_bit( 2 );
        read_bit( 1 );
        read_bit( 0 );
 
        i2c_data_oe = 1'b1;
        #tHD_DAT;
        i2c_data_out = 1'b0;
        #(tLOW - tHD_DAT);
        i2c_clk_out = 1'b1;
 
        if( LOG_LEVEL > 2 )
          $display( "###- %m: I2C read 0x%h at time %t. ", i2c_buffer_in, $time );
 
      end
  endtask
 
 
  // --------------------------------------------------------------------
  //  outputs  
  assign i2c_data = i2c_data_oe ? i2c_data_out  : 1'bz;
  assign i2c_clk  = i2c_clk_oe  ? i2c_clk_out   : 1'bz;
 
 
endmodule
 

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Subversion Repositories i2c_to_wb

[/] [i2c_to_wb/] [trunk/] [sim/] [models/] [i2c_master_model.v] - Blame information for rev 2

Line No.	Rev	Author	Line
1	2	qaztronic	`// --------------------------------------------------------------------`
2			`//`
3			`// --------------------------------------------------------------------`
4
5			`timescale 1ns/10ps
6
7
8			`module`
9			`i2c_master_model`
10			`#(`
11			`parameter LOG_LEVEL = 3`
12			`)`
13			`(`
14			`inout i2c_data,`
15			`inout i2c_clk`
16			`);`
17
18			`localparam tBUF = 4700;`
19			`localparam tSU_STA = 4700;`
20			`localparam tSU_DAT = 250;`
21			`localparam tHD_DAT = 0;`
22			`localparam tHD_STA = 4000;`
23			`localparam tLOW = 4700;`
24			`localparam tHIGH = 4000;`
25
26			`// --------------------------------------------------------------------`
27			`// wires & regs`
28			`wire i2c_data_in = i2c_data;`
29			`wire i2c_clk_in = i2c_clk;`
30
31			`reg i2c_data_oe;`
32			`reg i2c_clk_oe;`
33			`reg i2c_data_out;`
34			`reg i2c_clk_out;`
35
36			`reg i2c_ack_in;`
37
38
39			`// --------------------------------------------------------------------`
40			`// init`
41			`initial`
42			`begin`
43			`i2c_data_oe = 1'b0;`
44			`i2c_clk_oe = 1'b0;`
45			`i2c_data_out = 1'b1;`
46			`i2c_clk_out = 1'b1;`
47			`end`
48
49
50			`// --------------------------------------------------------------------`
51			`// start`
52			`task start;`
53			`begin`
54
55			`if( LOG_LEVEL > 2 )`
56			`$display( "###- %m: I2C start at time %t. ", $time );`
57
58			`i2c_data_out = 1'b1;`
59			`i2c_clk_out = 1'b1;`
60
61			`#tBUF;`
62
63			`i2c_data_oe = 1'b1;`
64			`i2c_clk_oe = 1'b1;`
65
66			`if( i2c_data != 1'b1 )`
67			`begin`
68			`#tHD_DAT;`
69			`i2c_data_out = 1'b1;`
70			`end`
71
72			`if( i2c_clk != 1'b1 )`
73			`begin`
74			`i2c_clk_out = 1'b1;`
75			`#tSU_DAT;`
76			`end`
77
78			`#tSU_STA;`
79			`i2c_data_out = 1'b0;`
80
81			`end`
82			`endtask`
83
84
85			`// --------------------------------------------------------------------`
86			`// stop`
87			`task stop;`
88			`begin`
89
90			`if( LOG_LEVEL > 2 )`
91			`$display( "###- %m: I2C stop at time %t. ", $time );`
92
93			`if( i2c_data != 1'b0 )`
94			`begin`
95			`#tHD_DAT;`
96			`i2c_data_out = 1'b0;`
97			`end`
98
99			`if( i2c_clk != 1'b1 )`
100			`begin`
101			`i2c_clk_out = 1'b1;`
102			`#tSU_DAT;`
103			`end`
104
105			`i2c_data_out = 1'b1;`
106			`i2c_clk_out = 1'b1;`
107
108			`i2c_data_oe = 1'b0;`
109			`i2c_clk_oe = 1'b0;`
110
111			`end`
112			`endtask`
113
114
115			`// --------------------------------------------------------------------`
116			`// write_bit`
117			`task write_bit;`
118			`input bit;`
119			`begin`
120
121			`#tHD_DAT;`
122			`i2c_data_oe = 1'b1;`
123			`i2c_data_out = bit;`
124			`#tLOW;`
125
126			`i2c_clk_out = 1'b1;`
127			`#tHIGH;`
128			`i2c_clk_out = 1'b0;`
129
130
131			`end`
132			`endtask`
133
134
135			`// --------------------------------------------------------------------`
136			`// write_byte`
137			`task write_byte;`
138			`input [7:0] data;`
139			`begin`
140
141			`if( LOG_LEVEL > 2 )`
142			`$display( "###- %m: I2C write 0x%h at time %t. ", data, $time );`
143
144			`#tHD_STA;`
145
146			`i2c_clk_out = 1'b0;`
147
148			`write_bit( data[7] );`
149			`write_bit( data[6] );`
150			`write_bit( data[5] );`
151			`write_bit( data[4] );`
152			`write_bit( data[3] );`
153			`write_bit( data[2] );`
154			`write_bit( data[1] );`
155			`write_bit( data[0] );`
156
157			`#tHD_DAT;`
158			`i2c_data_oe = 1'b0;`
159			`#tLOW;`
160
161			`i2c_clk_out = 1'b1;`
162
163			`i2c_ack_in = i2c_data;`
164
165			`if( LOG_LEVEL > 2 )`
166			`if( i2c_data )`
167			`$display( "###- %m: I2C NACK at time %t. ", $time );`
168			`else`
169			`$display( "###- %m: I2C ACK at time %t. ", $time );`
170
171			`#tHIGH;`
172
173			`end`
174			`endtask`
175
176
177			`// --------------------------------------------------------------------`
178			`// read_bit`
179			`reg [7:0] i2c_buffer_in;`
180
181			`task read_bit;`
182			`input [3:0] bit;`
183			`begin`
184
185			`i2c_data_oe = 1'b0;`
186
187			`#tHD_DAT;`
188			`i2c_buffer_in[bit] = i2c_data_in;`
189			`#tLOW;`
190
191			`i2c_clk_out = 1'b1;`
192			`#tHIGH;`
193			`i2c_clk_out = 1'b0;`
194
195
196			`end`
197			`endtask`
198
199
200			`// --------------------------------------------------------------------`
201			`// read_byte`
202			`task read_byte;`
203			`begin`
204
205			`#tHD_STA;`
206
207			`i2c_clk_out = 1'b0;`
208			`i2c_data_oe = 1'b0;`
209
210			`read_bit( 7 );`
211			`read_bit( 6 );`
212			`read_bit( 5 );`
213			`read_bit( 4 );`
214			`read_bit( 3 );`
215			`read_bit( 2 );`
216			`read_bit( 1 );`
217			`read_bit( 0 );`
218
219			`i2c_data_oe = 1'b1;`
220			`#tHD_DAT;`
221			`i2c_data_out = 1'b0;`
222			`#(tLOW - tHD_DAT);`
223			`i2c_clk_out = 1'b1;`
224
225			`if( LOG_LEVEL > 2 )`
226			`$display( "###- %m: I2C read 0x%h at time %t. ", i2c_buffer_in, $time );`
227
228			`end`
229			`endtask`
230
231
232			`// --------------------------------------------------------------------`
233			`// outputs`
234			`assign i2c_data = i2c_data_oe ? i2c_data_out : 1'bz;`
235			`assign i2c_clk = i2c_clk_oe ? i2c_clk_out : 1'bz;`
236
237
238			`endmodule`
239