99 lines
2.1 KiB
Plaintext
99 lines
2.1 KiB
Plaintext
/*
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* This file is part of libsidplayfp, a SID player engine.
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*
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* Copyright 2011-2014 Leandro Nini <drfiemost@users.sourceforge.net>
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* Copyright 2007-2010 Antti Lankila
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* Copyright 2000 Simon White
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef FLAGS_H
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#define FLAGS_H
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#include <stdint.h>
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namespace libsidplayfp
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{
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/**
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* Processor status flag.
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*/
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class Flags
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{
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public:
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bool C; ///< Carry
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bool Z; ///< Zero
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bool I; ///< Interrupt disabled
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bool D; ///< Decimal
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bool B; ///< Break
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bool V; ///< Overflow
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bool N; ///< Negative
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public:
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void reset()
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{
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C = Z = I = D = V = N = false;
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B = true;
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}
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/**
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* Set N and Z flag values.
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*
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* @param value to set flags from
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*/
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void setNZ(uint8_t value)
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{
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Z = value == 0;
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N = value & 0x80;
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}
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/**
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* Get status register value.
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*/
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uint8_t get()
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{
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uint8_t sr = 0x20;
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if (C) sr |= 0x01;
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if (Z) sr |= 0x02;
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if (I) sr |= 0x04;
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if (D) sr |= 0x08;
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if (B) sr |= 0x10;
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if (V) sr |= 0x40;
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if (N) sr |= 0x80;
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return sr;
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}
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/**
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* Set status register value.
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*/
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void set(uint8_t sr)
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{
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C = sr & 0x01;
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Z = sr & 0x02;
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I = sr & 0x04;
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D = sr & 0x08;
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B = sr & 0x10;
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V = sr & 0x40;
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N = sr & 0x80;
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}
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};
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}
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#endif
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