quick draft/boilerplate code for the Patinho Feio CPU emulation module

src/devices/cpu/patinhofeio/patinho_feio.cpp

@@ -0,0 +1,73 @@
+// license:GPL2+
+// copyright-holders:Felipe Sanches
+/*
+    Patinho Feio
+*/
+
+#include "emu.h"
+#include "debugger.h"
+#include "patinho_feio.h"
+
+#define CI      m_ci //The program counter is called "contador de instrucoes" in portuguese
+#define ACC      m_acc
+
+#define ADDRESS_MASK_4K    0xFFF
+#define INCREMENT_CI_4K    (CI = (CI+1) & ADDRESS_MASK_4K)
+
+const device_type PATINHO_FEIO  = &device_creator<patinho_feio_device>;
+
+patinho_feio_device::patinho_feio_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+	: cpu_device(mconfig, PATINHO_FEIO, "PATINHO FEIO", tag, owner, clock, "patinho_feio_cpu", __FILE__)
+{
+}
+
+void patinho_feio_device::device_start()
+{
+	m_ci = 0;
+	m_acc = 0;
+
+    m_program = &space(AS_PROGRAM);
+
+	save_item(NAME(m_ci));
+	save_item(NAME(m_acc));
+
+	// Register state for debugger
+	state_add( PATINHO_FEIO_PC,         "CI",       m_pc         ).mask(0xFFF);
+	state_add( PATINHO_FEIO_ACC,        "ACC",      m_acc        ).mask(0xFF);
+}
+
+
+void patinho_feio_device::device_reset()
+{
+}
+/* execute instructions on this CPU until icount expires */
+void patinho_feio_device::execute_run()
+{
+	do
+	{
+		debugger_instruction_hook(this, CI);
+
+		if ((! m_run)){
+			m_icount = 0;   /* if processor is stopped, just burn cycles */
+        } else {
+            execute_instruction();
+			m_icount --;
+		}
+	}
+	while (m_icount > 0);
+}
+
+
+/* execute one instruction */
+void patinho_feio_device::execute_instruction()
+{
+//    char opcode = patinho_feio_read(CI);
+    INCREMENT_CI_4K;
+}
+
+offs_t patinho_feio_device::disasm_disassemble(char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, UINT32 options)
+{
+	extern CPU_DISASSEMBLE( patinho_feio );
+	return CPU_DISASSEMBLE_NAME(patinho_feio)(this, buffer, pc, oprom, opram, options);
+}
+

src/devices/cpu/patinhofeio/patinho_feio.h

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+// license:GPL2+
+// copyright-holders:Felipe Sanches
+#pragma once
+
+#ifndef __PATINHOFEIO_H__
+#define __PATINHOFEIO_H__
+
+/* register IDs */
+enum
+{
+	PATINHOFEIO_CI=1, PATINHOFEIO_ACC
+};
+
+class patinho_feio_device : public cpu_device
+{
+public:
+	// construction/destruction
+	patinho_feio_device(const machine_config &mconfig, const char *_tag, device_t *_owner, UINT32 _clock);
+
+protected:
+	virtual void execute_run();
+	virtual offs_t disasm_disassemble(char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, UINT32 options);
+
+    address_space_config m_program_config;
+
+    /* processor registers */
+    int m_acc;        /* accumulator (8 bits) */
+    int m_ci;         /* program counter (12 bits) (CI stands for "Contador de Instrucao")*/
+
+    /* processor state flip-flops */
+    unsigned int m_run;       /* processor is running */
+
+    int m_address_mask;       /* address mask */
+    int m_ir_mask;            /* IR mask */
+    int m_icount;
+
+    address_space *m_program;
+
+    // device-level overrides
+    virtual void device_start();
+    virtual void device_reset();
+
+    // device_execute_interface overrides
+    virtual UINT32 execute_min_cycles() const { return 1; }
+    virtual UINT32 execute_max_cycles() const { return 3; }
+
+    // device_memory_interface overrides
+    virtual const address_space_config *memory_space_config(address_spacenum spacenum = AS_0) const { return (spacenum == AS_PROGRAM) ? &m_program_config : NULL; }
+
+    // device_disasm_interface overrides
+    virtual UINT32 disasm_min_opcode_bytes() const { return 4; }
+    virtual UINT32 disasm_max_opcode_bytes() const { return 4; }
+
+private:
+	void execute_instruction();
+};
+
+
+extern const device_type PATINHO_FEIO;
+
+#endif /* __PATINHOFEIO_H__ */

src/devices/cpu/patinhofeio/patinho_feio_dasm.cpp

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+// license:GPL2+
+// copyright-holders:Felipe Sanches
+#include "emu.h"
+#include "cpu/patinhofeio/patinho_feio.h"
+
+CPU_DISASSEMBLE( patinho_feio )
+{
+//	int md;
+//	int x;
+//	md = oprom[1] << 8 | oprom[0];
+//	x = md & 0xFFF;
+    
+    //single-opcode instructions
+	switch (oprom[0])
+	{
+    case 0x80:
+        sprintf (buffer, "LIMPO");
+        break;
+    case 0x85:
+        sprintf (buffer, "INC");
+        break;
+    case 0x96:
+        sprintf (buffer, "SV 1");
+        break;
+    case 0x99:
+        sprintf (buffer, "TRE");
+        break;
+    case 0x9D:
+        sprintf (buffer, "PARE");
+        break;
+    default:
+		sprintf (buffer, "illegal");
+		break;
+	}
+	return 1;
+}