Stage 6: implementation, untested

src/main/scala/projet/ImmediateDecoder.scala

@@ -16,10 +16,11 @@ class ImmediateDecoder extends Module {
     })
     io.immediate := 0.U
 
-    // Decode imm-u
+    // Decode and construct immediates
     val imm_u = Cat(io.instruction(31, 12), 0.U(12.W));
-    // Decode imm-i
     val imm_i = Cat(Fill(20, io.instruction(31)), io.instruction(31, 20));
+    val imm_ir = io.instruction(24, 20);
+
     switch(io.op_type) {
         is(OpType.U) {
             io.immediate := imm_u
@@ -27,5 +28,8 @@ class ImmediateDecoder extends Module {
         is(OpType.I) {
             io.immediate := imm_i
         }
+        is(OpType.IR) {
+            io.immediate := imm_ir
+        }
     }
 }