--- nono/vm/bus.h	2026/04/29 17:05:29	1.1.1.7
+++ nono/vm/bus.h	2026/04/29 17:05:33	1.1.1.8
@@ -58,6 +58,7 @@ enum class BusAddr : uint64
 	Write			= D | W,
 	SRead			= S | Read,
 	SWrite			= S | Write,
+	FCMask			= 0x0000'000f'0000'0000ULL,
 
 	Size1			= 0x0001'0000'0000'0000ULL,
 	Size2			= 0x0002'0000'0000'0000ULL,
@@ -153,6 +154,10 @@ class busaddr
 			value &= ~(uint64)BusAddr::S;
 		}
 	}
+	void ChangeFC(uint32 fc_) noexcept {
+		value &= ~(uint64)BusAddr::FCMask;
+		value |= (uint64)busaddr::FC(fc_);
+	}
 	void ChangeData(bool data_) noexcept {
 		value &= ~(uint64)(BusAddr::I | BusAddr::D);
 		if (data_) {