libsidplayfp 1.0.3
c64cia.h
00001 /*
00002  * This file is part of libsidplayfp, a SID player engine.
00003  *
00004  * Copyright 2011-2013 Leandro Nini <drfiemost@users.sourceforge.net>
00005  * Copyright 2007-2010 Antti Lankila
00006  * Copyright 2001 Simon White
00007  *
00008  * This program is free software; you can redistribute it and/or modify
00009  * it under the terms of the GNU General Public License as published by
00010  * the Free Software Foundation; either version 2 of the License, or
00011  * (at your option) any later version.
00012  *
00013  * This program is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  * GNU General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU General Public License
00019  * along with this program; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
00021  */
00022 
00023 #ifndef C64CIA_H
00024 #define C64CIA_H
00025 
00026 // The CIA emulations are very generic and here we need to effectively
00027 // wire them into the computer (like adding a chip to a PCB).
00028 
00029 #include "Banks/Bank.h"
00030 #include "sidplayfp/c64/c64env.h"
00031 #include "sidplayfp/sidendian.h"
00032 #include "CIA/mos6526.h"
00033 
00039 class c64cia1: public MOS6526, public Bank
00040 {
00041 private:
00042     c64env &m_env;
00043     uint_least16_t last_ta;
00044     uint8_t lp;
00045 
00046 protected:
00047     void interrupt(bool state)
00048     {
00049         m_env.interruptIRQ (state);
00050     }
00051 
00052     void portB()
00053     {
00054         const uint8_t lp = (prb | ~ddrb) & 0x10;
00055         if (lp != this->lp)
00056         {
00057             m_env.lightpen();
00058             this->lp = lp;
00059         }
00060     }
00061 
00062 public:
00063     c64cia1(c64env *env) :
00064         MOS6526(&(env->context ())),
00065         m_env(*env) {}
00066 
00067     void poke(uint_least16_t address, uint8_t value)
00068     {
00069         write(endian_16lo8(address), value);
00070 
00071         // Save the value written to Timer A
00072         if (address == 0xDC04 || address == 0xDC05)
00073         {
00074             if (timerA.getTimer() != 0)
00075                 last_ta = timerA.getTimer();
00076         }
00077     }
00078 
00079     uint8_t peek(uint_least16_t address)
00080     {
00081         return read(endian_16lo8(address));
00082     }
00083 
00084     const char *error() const { return ""; }
00085 
00086     void reset()
00087     {
00088         last_ta = 0;
00089         lp = 0x10;
00090         MOS6526::reset ();
00091     }
00092 
00093     uint_least16_t getTimerA() const { return last_ta; }
00094 };
00095 
00101 class c64cia2: public MOS6526, public Bank
00102 {
00103 private:
00104     c64env &m_env;
00105 
00106 protected:
00107     void interrupt(bool state)
00108     {
00109         if (state)
00110             m_env.interruptNMI ();
00111     }
00112 
00113 public:
00114     c64cia2(c64env *env) :
00115         MOS6526(&(env->context ())),
00116         m_env(*env) {}
00117 
00118     void poke(uint_least16_t address, uint8_t value)
00119     {
00120         write(address, value);
00121     }
00122 
00123     uint8_t peek(uint_least16_t address)
00124     {
00125         return read(address);
00126     }
00127 
00128     const char *error() const { return ""; }
00129 };
00130 
00131 #endif // C64CIA_H