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authorJosh Blum <josh@joshknows.com>2010-04-15 11:24:24 -0700
committerJosh Blum <josh@joshknows.com>2010-04-15 11:24:24 -0700
commit05d77f772317de5d925301aa11bb9a880656dd05 (patch)
tree0910bfb9265fab1644a3d3a1706719f1b038d193 /fpga/usrp2/models/cpld_model.v
parent16818dc98e97b69a028c47e66ebfb16e32565533 (diff)
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moved usrp1 and usrp2 fpga dirs into fpga subdirectory
Diffstat (limited to 'fpga/usrp2/models/cpld_model.v')
-rw-r--r--fpga/usrp2/models/cpld_model.v96
1 files changed, 96 insertions, 0 deletions
diff --git a/fpga/usrp2/models/cpld_model.v b/fpga/usrp2/models/cpld_model.v
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+++ b/fpga/usrp2/models/cpld_model.v
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+
+module cpld_model
+ (input aux_clk, input start, input mode, input done,
+ output dout, output reg sclk, output detached);
+
+ reg [7:0] rom[0:65535];
+
+ reg [15:0] addr;
+ reg [7:0] data;
+ assign dout = data[7];
+
+ reg [2:0] state, bitcnt;
+
+ localparam IDLE = 3'd0;
+ localparam READ = 3'd1;
+ localparam BIT1 = 3'd2;
+ localparam BIT2 = 3'd3;
+ localparam DONE = 3'd4;
+ localparam DETACHED = 3'd5;
+ localparam ERROR = 3'd7;
+
+ integer i;
+ reg [1023:0] ROMFile;
+
+ initial begin
+ for (i=0;i<65536;i=i+1) begin
+ rom[i] <= 32'h0;
+ end
+ if ( !$value$plusargs( "rom=%s", ROMFile ) )
+ begin
+ $display( "Using default ROM file, 'flash.rom'" );
+ ROMFile = "flash.rom";
+ end
+ else
+ $display( "Using %s as ROM file.", ROMFile);
+
+ #1 $readmemh( ROMFile,rom );
+ end
+
+ initial addr = 16'd0;
+ initial data = 8'd0;
+ initial state = IDLE;
+ initial bitcnt = 3'd0;
+ initial sclk = 1'b0;
+
+ always @(posedge aux_clk)
+ case(state)
+ IDLE :
+ if(start)
+ if(~mode)
+ state <= READ;
+ else
+ state <= ERROR;
+ READ :
+ if(done)
+ state <= DONE;
+ else
+ begin
+ data <= rom[addr];
+ addr <= addr + 1;
+ bitcnt <= 3'd0;
+ if(addr==16'hFFFF)
+ state <= ERROR;
+ else
+ state <= BIT1;
+ end // else: !if(start)
+ BIT1 :
+ begin
+ sclk <= 1'b1;
+ state <= BIT2;
+ end
+ BIT2 :
+ begin
+ sclk <= 1'b0;
+ data <= {data[6:0],1'b0};
+ bitcnt <= bitcnt + 1;
+ if(bitcnt==7)
+ state <= READ;
+ else
+ state <=BIT1;
+ end
+ DONE :
+ begin
+ if(start)
+ state <= ERROR;
+ else
+ state <= DETACHED;
+ end
+ DETACHED :
+ if(start)
+ state <= ERROR;
+ endcase // case(state)
+
+ assign detached = (state == DETACHED) || (state == IDLE);
+
+endmodule // cpld_model