diff --git a/Labs/05. Main decoder/csr_pkg.sv b/Labs/05. Main decoder/csr_pkg.sv
new file mode 100644
index 00000000..bf37986f
--- /dev/null
+++ b/Labs/05. Main decoder/csr_pkg.sv	
@@ -0,0 +1,16 @@
+package csr_pkg;
+
+  localparam CSR_RW          = 3'b001;
+  localparam CSR_RS          = 3'b010;
+  localparam CSR_RC          = 3'b011;
+  localparam CSR_RWI         = 3'b101;
+  localparam CSR_RSI         = 3'b110;
+  localparam CSR_RCI         = 3'b111;
+  
+  localparam MIE_ADDR        = 12'h304;
+  localparam MTVEC_ADDR      = 12'h305;
+  localparam MSCRATCH_ADDR   = 12'h340;
+  localparam MEPC_ADDR       = 12'h341;
+  localparam MCAUSE_ADDR     = 12'h342;
+
+endpackage