diff --git a/inc/Registers.h b/inc/Registers.h
index f2d1194..eef56a0 100644
--- a/inc/Registers.h
+++ b/inc/Registers.h
@@ -11,6 +11,7 @@
 
 #define SC_INCLUDE_DYNAMIC_PROCESSES
 #include <iomanip>
+#include <unordered_map>
 
 #include "systemc"
 #include "tlm.h"
@@ -254,7 +255,10 @@ private:
 	/**
 	 * CSR registers (4096 maximum)
 	 */
-	uint32_t CSR[4096];
+	//uint32_t CSR[4096];
+	std::unordered_map<unsigned int, uint32_t> CSR;
+
+
 	Performance *perf;
 
 	void initCSR(void);
diff --git a/src/Registers.cpp b/src/Registers.cpp
index b49f6f8..cc7dc09 100644
--- a/src/Registers.cpp
+++ b/src/Registers.cpp
@@ -11,7 +11,7 @@
 Registers::Registers() {
 
 	memset(register_bank, 0, sizeof(uint32_t) * 32); // 32 registers of 32 bits each
-	memset(CSR, 0, sizeof(uint32_t) * 4096);
+	//memset(CSR, 0, sizeof(uint32_t) * 4096);
 	perf = Performance::getInstance();
 
 	initCSR();
@@ -156,7 +156,7 @@ uint32_t Registers::getCSR(int csr) {
 						- sc_core::sc_time(sc_core::SC_ZERO_TIME)).to_double())
 				>> 32 & 0x00000000FFFFFFFF);
 		break;
-	default:
+	[[likely]] default:
 		ret_value = CSR[csr];
 		break;
 	}