twos_compl_to_ieee.v

IEEE754 floating point sub

/* ------------------------------------------------------------
// MODULE: Twos_compl_to_IEEE (no clock )
// Edition: one
// Matlab Code:  None
// C Code: None
// Architecture Diagram: None
// Date: 2008/01/30
// Update: 2008/01/30	   
// ------------------------------------------------------------ */
module Twos_compl_to_IEEE(data_in,data_out);
/* ------------------------------------------------------------
// Parameters definition
// ------------------------------------------------------------ */

parameter data_lng=32,//data_in length
	  exp_lng=7,//data_in exponent part length
	  sgnfc_lng=25;//data_in significant part length
 
/* ------------------------------------------------------------
// I/O declaration
// ------------------------------------------------------------ */
input [data_lng-1:0]data_in; //include sgnfc and exp part

output [data_lng-1:0]data_out; // data_out
/* ------------------------------------------------------------
// Connection wire declaration
// ------------------------------------------------------------ */
wire sign,con_case_ctrl,min_overflow;

wire [sgnfc_lng-1:0]spec_data_sgnfc,con_data_sgnfc;

wire [exp_lng-1:0]con_data_exp,spec_data_exp;
/* ------------------------------------------------------------
// Module instance
// ------------------------------------------------------------ */
assign sign=data_in[data_lng-1];

assign con_case_ctrl=|data_in[data_lng-2:exp_lng];//check if 1000000...000(-2)

assign con_data_sgnfc=(sign)?~data_in[data_lng-1:sgnfc_lng]+1'b1:data_in[data_lng-1:sgnfc_lng];//conventional case

assign spec_data_sgnfc=data_in[data_lng-1:sgnfc_lng]>>1; //special case -2=>+1

assign con_data_exp=data_in[exp_lng-1:0];

assign spec_data_exp=con_data_exp+1'b1;

assign min_overflow=(&{con_data_exp,sign});

assign data_out[data_lng-1:sgnfc_lng]=(con_case_ctrl)?con_data_sgnfc:((min_overflow)?{sgnfc_lng{1'b0}}:spec_data_sgnfc);

assign data_out[sgnfc_lng-1:0]=(con_case_ctrl)?con_data_exp:spec_data_exp;

endmodule