/******************************************************************************/
/* */
/* Copyright (c) 1999 Sun Microsystems, Inc. All rights reserved. */
/* */
/* The contents of this file are subject to the current version of the Sun */
/* Community Source License, microSPARCII ("the License"). You may not use */
/* this file except in compliance with the License. You may obtain a copy */
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/* */
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/******************************************************************************/
// @(#)resultexception.v 1.1 4/7/92
//
module ResultException
(Result, SNnotDB, ExpZero, notUnderflow, notOverflow, notExpException);
input [`ExpMSB:0] Result
;
input ExpZero
;
input SNnotDB
;
output notUnderflow
, notOverflow
, notExpException
;
ME_TIEOFF toff (vdd
, );
ME_INV_B g30 ( Result[12], positive
) ;
ME_INV_A g31 ( SNnotDB, DBnotSN
) ;
// underflow condition is -ve or all zero.
// Note that exp must be subtracting for zero to work !
ME_NMUX2B zq1 (positive, vdd, ExpZero, notUnderflow );
// overflow condition is positive and all ones with LSB dont care.
// or positive with bit 11 set.
// n.b all ones applies only over required length.
// Force bits 10 to 8 high when single and AND them
ME_NAND3 g10 (Result[10], Result[9], Result[8], n10
) ;
ME_NAND2 g11 (DBnotSN, n10, doublebits1
) ;
ME_AND4 zzd (Result[7], Result[6], Result[5], Result[4], All1s7to4
);
ME_AND4_B zze (positive, Result[3], Result[2], Result[1], PAll1s3to1
);
ME_OR3_B zzf ( Result[10], Result[9], Result[8], Bit10Or8
);
ME_NAND3_B g23 ( positive, SNnotDB, Bit10Or8, notSNGrossOv
) ;
ME_NAND3_B g22 ( doublebits1, All1s7to4, PAll1s3to1, notAll1s
) ;
ME_NAND2 g21 ( positive, Result[11], notBit11
) ;
ME_AND3_B g20 ( notSNGrossOv, notAll1s, notBit11, notOverflow ) ;
ME_AND4_B g24 ( notUnderflow, notSNGrossOv, notAll1s, notBit11, notExpException ) ;
endmodule
This page: |
Created: | Thu Aug 19 12:03:23 1999 |
| From: |
../../../sparc_v8/ssparc/fpu/fp_exp/rtl/resultexception.v
|