--- nono/vm/rp5c15.h	2026/04/29 17:04:32	1.1.1.2
+++ nono/vm/rp5c15.h	2026/04/29 17:04:36	1.1.1.3
@@ -1,6 +1,7 @@
 //
 // nono
-// Copyright (C) 2018 isaki@NetBSD.org
+// Copyright (C) 2020 nono project
+// Licensed under nono-license.txt
 //
 
 #pragma once
@@ -102,27 +103,25 @@ struct RP5C15
 
 class RP5C15Device : public RTCDevice
 {
-	typedef RTCDevice inherited;
+	using inherited = RTCDevice;
  public:
 	RP5C15Device();
-	virtual ~RP5C15Device();
+	~RP5C15Device() override;
 
-	virtual bool InitRTC();
-
-	virtual uint64 Read8(uint32 addr);
-	virtual uint64 Read16(uint32 addr);
-	virtual uint64 Write8(uint32 addr, uint32 data);
-	virtual uint64 Write16(uint32 addr, uint32 data);
-	virtual uint64 Peek8(uint32 addr);
-	virtual bool MonitorUpdate();
+	bool InitRTC() override;
+	bool MonitorUpdate() override;
 
 	// 32Hz クロック入力
-	virtual void ClockIn();
+	void ClockIn() override;
 
- private:
-	// アドレスデコーダ
-	uint64 Decoder(uint32 addr) const;
+ protected:
+	// BusIO インタフェース
+	static const uint32 NPORT = 16;
+	uint64 Read(uint32 addr);
+	uint64 Write(uint32 addr, uint32 data);
+	uint64 Peek(uint32 addr);
 
+ private:
 	// レジスタを更新
 	void UpdateReg(uint32);