initial commit

cpu.h

@@ -0,0 +1,78 @@
+#ifndef BEAR_CPU_H
+#define BEAR_CPU_H
+
+#include "common.h"
+#include "memory.h"
+
+class CPU
+{
+public:
+    explicit CPU(IMemoryAccessor* memory);
+
+    void start();
+    void reset();
+private:
+    enum STATUS_FLAGS
+    {
+        C = 1 << 0,
+        Z = 1 << 1,
+        I = 1 << 2,
+        D = 1 << 3,
+        B = 1 << 4,
+        O = 1 << 6,
+        N = 1 << 7,
+    };
+
+    uint8_t a;
+    uint8_t x, y;
+
+    uint16_t pc;
+
+    uint8_t sp;
+
+    IMemoryAccessor* _memory;
+
+    // Stat flags
+    uint8_t stat;
+
+    int cycles;
+
+    bool stop;
+
+    void c(const bool _v) { _v ? (stat |= C) : stat &= ~C; }
+    [[nodiscard]] bool c() const { return (stat & C) > 0; }
+
+    void z(const bool _v) { _v ? (stat |= Z) : stat &= ~Z; }
+    [[nodiscard]] bool z() const { return (stat & Z) > 0; }
+
+    void i(const bool _v) { _v ? (stat |= I) : stat &= ~I; }
+    [[nodiscard]] bool i() const { return (stat & I) > 0; }
+
+    void d(const bool _v) { _v ? (stat |= D) : stat &= ~D; }
+    [[nodiscard]] bool d() const { return (stat & D) > 0; }
+
+    void b(const bool _v) { _v ? (stat |= B) : stat &= ~B; }
+    [[nodiscard]] bool b() const { return (stat & B) > 0; }
+
+    void o(const bool _v) { _v ? (stat |= O) : stat &= ~O; }
+    [[nodiscard]] bool o() const { return (stat & O) > 0; }
+    // END Stat flags
+
+    void loop();
+
+    [[nodiscard]] std::uint8_t readImm() const;
+    [[nodiscard]] std::uint8_t readZp() const;
+    [[nodiscard]] std::uint8_t readZpX() const;
+    [[nodiscard]] std::uint8_t readAbs();
+    [[nodiscard]] std::uint8_t readAbsX();
+    [[nodiscard]] std::uint8_t readAbsY();
+    [[nodiscard]] std::uint8_t readIdxInd();
+    [[nodiscard]] std::uint8_t readIndIdx();
+
+    void adc(std::uint8_t val);
+
+    void setFlagsFromResult(std::uint16_t result);
+};
+
+
+#endif //BEAR_CPU_H