// ============================================================================
|
// ============================================================================
|
// __
|
// __
|
// \\__/ o\ (C) 2020 Robert Finch, Waterloo
|
// \\__/ o\ (C) 2020 Robert Finch, Waterloo
|
// \ __ / All rights reserved.
|
// \ __ / All rights reserved.
|
// \/_// robfinch@finitron.ca
|
// \/_// robfinch@finitron.ca
|
// ||
|
// ||
|
//
|
//
|
// positToFp.v
|
// positToFp.sv
|
// - posit number to floating point convertor
|
// - posit number to floating point convertor
|
// - can issue every clock cycle
|
// - can issue every clock cycle
|
// - parameterized width
|
// - parameterized width
|
// - IEEE 754 representation
|
// - IEEE 754 representation
|
//
|
//
|
// Parts of this code originated from Posit_to_FP.v by Manish Kumar Jaiswal
|
// Parts of this code originated from Posit_to_FP.v by Manish Kumar Jaiswal
|
//
|
//
|
// This source file is free software: you can redistribute it and/or modify
|
// This source file is free software: you can redistribute it and/or modify
|
// it under the terms of the GNU Lesser General Public License as published
|
// it under the terms of the GNU Lesser General Public License as published
|
// by the Free Software Foundation, either version 3 of the License, or
|
// by the Free Software Foundation, either version 3 of the License, or
|
// (at your option) any later version.
|
// (at your option) any later version.
|
//
|
//
|
// This source file is distributed in the hope that it will be useful,
|
// This source file is distributed in the hope that it will be useful,
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
// GNU General Public License for more details.
|
// GNU General Public License for more details.
|
//
|
//
|
// You should have received a copy of the GNU General Public License
|
// You should have received a copy of the GNU General Public License
|
// along with this program. If not, see .
|
// along with this program. If not, see .
|
//
|
//
|
// ============================================================================
|
// ============================================================================
|
|
|
`include "positConfig.sv"
|
import posit::*;
|
`include "fpConfig.sv"
|
import fp::*;
|
`include "fpTypes.sv"
|
`include "../fpu/fpTypes.sv"
|
|
|
module positToFp(i, o);
|
module positToFp(i, o);
|
parameter FPWID = 32;
|
|
`include "fpSize.sv"
|
|
`include "positSize.sv"
|
|
input [FPWID-1:0] i;
|
input [FPWID-1:0] i;
|
output reg [FPWID-1:0] o;
|
output reg [FPWID-1:0] o;
|
|
|
parameter BIAS = {1'b0,{EMSB{1'b1}}};
|
parameter BIAS = {1'b0,{EMSB{1'b1}}};
|
localparam N = FPWID;
|
localparam N = FPWID;
|
localparam E = EMSB+1;
|
localparam E = EMSB+1;
|
localparam M = FMSB+1;
|
localparam M = FMSB+1;
|
localparam Bs = $clog2(FPWID-1);
|
localparam Bs = $clog2(FPWID-1);
|
localparam EO = E > es+Bs ? E : es+Bs;
|
localparam EO = E > es+Bs ? E : es+Bs;
|
|
|
wire sgn;
|
wire sgn;
|
wire rgs;
|
wire rgs;
|
wire [Bs-1:0] rgm;
|
wire [Bs-1:0] rgm;
|
wire [es-1:0] exp;
|
wire [es-1:0] exp;
|
wire [N-es-1:0] sig;
|
wire [N-es-1:0] sig;
|
wire zer;
|
wire zer;
|
wire inf;
|
wire inf;
|
|
|
positDecompose #(.PSTWID(PSTWID), .es(es)) u1 (.i(i), .sgn(sgn), .rgs(rgs), .rgm(rgm), .exp(exp), .sig(sig), .zer(zer), .inf(inf));
|
positDecompose #(.PSTWID(PSTWID)) u1 (.i(i), .sgn(sgn), .rgs(rgs), .rgm(rgm), .exp(exp), .sig(sig), .zer(zer), .inf(inf));
|
|
|
wire [N-1:0] m = {sig,{es{1'b0}}};
|
wire [N-1:0] m = {sig,{es{1'b0}}};
|
wire [EO+1:0] e;
|
wire [EO+1:0] e;
|
assign e = {(rgs ? {{EO-es-Bs+1{1'b0}},rgm} : -{{EO-es-Bs+1{1'b0}},rgm}),exp} + BIAS;
|
assign e = {(rgs ? {{EO-es-Bs+1{1'b0}},rgm} : -{{EO-es-Bs+1{1'b0}},rgm}),exp} + BIAS;
|
wire exv = |e[EO:E];
|
wire exv = |e[EO:E];
|
wire exinf = &e[E-1:0];
|
wire exinf = &e[E-1:0];
|
|
|
always @*
|
always @*
|
casez({zer,inf|exv|exinf}) // exponent all ones or exponent overflow?
|
casez({zer,inf|exv|exinf}) // exponent all ones or exponent overflow?
|
// convert to +0.0 zero-in zero-out (the sign will always be plus)
|
// convert to +0.0 zero-in zero-out (the sign will always be plus)
|
2'b1?: o = {sgn,{FPWID-1{1'b0}}};
|
2'b1?: o = {sgn,{FPWID-1{1'b0}}};
|
// Infinity in or exponent overflow in conversion = infinity out
|
// Infinity in or exponent overflow in conversion = infinity out
|
2'b01: o = {sgn,{E-1{1'b1}},{M{1'b0}}};
|
2'b01: o = {sgn,{E-1{1'b1}},{M{1'b0}}};
|
// Other numbers
|
// Other numbers
|
default: o = {sgn,e[E-1:0],m[N-2:E]};
|
default: o = {sgn,e[E-1:0],m[N-2:E]};
|
endcase
|
endcase
|
|
|
endmodule
|
endmodule
|
|
|
