1 // license:BSD-3-Clause
2 // copyright-holders:David Shah, David Haywood
3 /***************************************************************************
4 
5     m6502_swap_op_d5_d6.h
6 
7     6502 / N2A03 with instruction scrambling
8 
9 ***************************************************************************/
10 
11 #ifndef MAME_M6502_SWAP_OP_D5_D6_H
12 #define MAME_M6502_SWAP_OP_D5_D6_H
13 
14 #pragma once
15 
16 #include "cpu/m6502/n2a03.h"
17 #include "cpu/m6502/n2a03d.h"
18 
19 class m6502_swap_op_d5_d6 : public m6502_device {
20 public:
21 	m6502_swap_op_d5_d6(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
22 
23 protected:
24 	class mi_decrypt : public mi_default {
25 	public:
26 
~mi_decrypt()27 		virtual ~mi_decrypt() {}
28 		virtual uint8_t read_sync(uint16_t adr) override;
29 
30 		uint8_t descramble(uint8_t op);
31 	};
32 
33 	class disassembler : public m6502_disassembler {
34 	public:
35 		mi_decrypt *mintf;
36 
37 		disassembler(mi_decrypt *m);
38 		virtual ~disassembler() = default;
39 		virtual u32 interface_flags() const override;
40 		virtual u8 decrypt8(u8 value, offs_t pc, bool opcode) const override;
41 	};
42 
43 	virtual void device_reset() override;
44 	virtual void device_start() override;
45 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
46 };
47 
48 class n2a03_core_swap_op_d5_d6 : public n2a03_core_device {
49 public:
50 	n2a03_core_swap_op_d5_d6(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
51 
52 protected:
53 	class mi_decrypt : public mi_default {
54 	public:
55 
~mi_decrypt()56 		virtual ~mi_decrypt() {}
57 		virtual uint8_t read_sync(uint16_t adr) override;
58 
59 		uint8_t descramble(uint8_t op);
60 	};
61 
62 	class disassembler : public n2a03_disassembler {
63 	public:
64 		mi_decrypt *mintf;
65 
66 		disassembler(mi_decrypt *m);
67 		virtual ~disassembler() = default;
68 		virtual u32 interface_flags() const override;
69 		virtual u8 decrypt8(u8 value, offs_t pc, bool opcode) const override;
70 	};
71 
72 	virtual void device_reset() override;
73 	virtual void device_start() override;
74 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
75 };
76 
77 
78 DECLARE_DEVICE_TYPE(M6502_SWAP_OP_D5_D6, m6502_swap_op_d5_d6)
79 DECLARE_DEVICE_TYPE(N2A03_CORE_SWAP_OP_D5_D6, n2a03_core_swap_op_d5_d6)
80 
81 #endif // MAME_M6502_SWAP_OP_D5_D6_H
82