| Line 7... |
Line 7... |
//
|
//
|
// positSqrt.v
|
// positSqrt.v
|
// - posit number square root function
|
// - posit number square root function
|
// - parameterized width
|
// - parameterized width
|
//
|
//
|
/////////////////////////////////////////////////////////////////////////////////
|
|
/////////////////////////////////////////////////////////////////////////////////
|
|
// This function currently only seems to work with even sizes of
|
|
// exponents.
|
|
/////////////////////////////////////////////////////////////////////////////////
|
|
/////////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
//
|
//
|
// 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.
|
| Line 66... |
Line 59... |
.zer(zeri),
|
.zer(zeri),
|
.inf(infi)
|
.inf(infi)
|
);
|
);
|
|
|
assign so = si; // square root of positive numbers only
|
assign so = si; // square root of positive numbers only
|
|
// Compute length of significand. This length is needed to align the
|
|
// significand input to the square root module.
|
|
//wire [rs+1:0] rgml1 = rgsi ? rgmi + 2'd2 : rgmi + 2'd1;
|
|
//wire [rs+1:0] sigl = PSTWID-rgml1-es-1;
|
|
// The length could be zero or less
|
|
//wire [rs:0] sigl1 = sigl[rs+1] ? {rs{1'b0}} : sigl;
|
|
|
|
// Compute exponent
|
wire [rs+1:0] rgm1 = rgsi ? rgmi : -rgmi;
|
wire [rs+1:0] rgm1 = rgsi ? rgmi : -rgmi;
|
wire [rs+es+1:0] rx1 = {rgm1,expi};
|
wire [rs+es+1:0] rx1 = {rgm1,expi};
|
// If exponent is odd, make it even. May need to shift the significand later.
|
// If exponent is odd, make it even. May need to shift the significand later.
|
wire [rs+es+1:0] rxtmp = {{2{rx1[rs+es+1]}},rx1} >> 1; // right shift takes square root of exponent
|
wire [rs+es+1:0] rxtmp = {{2{rx1[rs+es+1]}},rx1} >> 1; // right shift takes square root of exponent
|
|
|
assign sqrinf = infi;
|
assign sqrinf = infi;
|
assign sqrneg = so;
|
assign sqrneg = so;
|
// If the exponent was made even, shift the significand left.
|
// If the exponent was made even, shift the significand left.
|
wire [PSTWID-1:0] sig1 = rx1[0] ? {sigi,1'b0} : {1'b0,sigi};
|
wire [PSTWID-1:0] sig1 = (rx1[0] ^ ~es[0]) ? {sigi,1'b0} : {1'b0,sigi};
|
|
|
wire ldd;
|
wire ldd;
|
delay1 #(1) u3 (.clk(clk), .ce(ce), .i(start), .o(ldd));
|
delay1 #(1) u3 (.clk(clk), .ce(ce), .i(start), .o(ldd));
|
wire [PSTWID*3-1:0] sqrto;
|
wire [PSTWID*3-1:0] sqrto;
|
|
|
| Line 89... |
Line 90... |
(
|
(
|
.rst(rst),
|
.rst(rst),
|
.clk(clk),
|
.clk(clk),
|
.ce(ce),
|
.ce(ce),
|
.ld(ldd),
|
.ld(ldd),
|
.a({sig1,{(PSTWID/2+1-(PSTWID%2)){1'b0}}}),
|
// Align the input according to odd/even length
|
|
.a({sig1,{PSTWID/2{1'b0}}}),
|
.o(sqrto),
|
.o(sqrto),
|
.done(done),
|
.done(done),
|
.lzcnt(lzcnt)
|
.lzcnt(lzcnt)
|
);
|
);
|
|
|
