diff --git a/osaca/data/isa/aarch64.yml b/osaca/data/isa/aarch64.yml
index 73c6223..7cd82a3 100644
--- a/osaca/data/isa/aarch64.yml
+++ b/osaca/data/isa/aarch64.yml
@@ -850,7 +850,7 @@ instruction_forms:
           shape: "*"
           source: true
           destination: false
-    - name: ldp
+    - name: [ldp, ldnp]
       operands:
         - class: register
           prefix: "*"
@@ -895,7 +895,7 @@ instruction_forms:
         source: true
         destination: false
       operation: "op1['name'] = op2['name']; op1['value'] = op2['value']"
-    - name: stp
+    - name: [stp, stnp]
       operands:
         - class: register
           prefix: "*"
diff --git a/osaca/parser/parser_AArch64.py b/osaca/parser/parser_AArch64.py
index 30dd9d6..9464443 100755
--- a/osaca/parser/parser_AArch64.py
+++ b/osaca/parser/parser_AArch64.py
@@ -382,7 +382,7 @@ class ParserAArch64(BaseParser):
         ):
             # resolve ranges and lists
             return self.resolve_range_list(self.process_register_list(operand[self.REGISTER_ID]))
-        if self.REGISTER_ID in operand and operand[self.REGISTER_ID]["name"] == "sp":
+        if self.REGISTER_ID in operand and operand[self.REGISTER_ID]["name"].lower() == "sp":
             return self.process_sp_register(operand[self.REGISTER_ID])
         # add value attribute to floating point immediates without exponent
         if self.IMMEDIATE_ID in operand:
@@ -404,9 +404,13 @@ class ParserAArch64(BaseParser):
         base = memory_address.get("base", None)
         index = memory_address.get("index", None)
         scale = 1
-        if base is not None and "name" in base and base["name"] == "sp":
+        if base is not None and "name" in base and base["name"].lower() == "sp":
             base["prefix"] = "x"
-        if index is not None and "name" in index and index["name"] == "sp":
+        if index is not None and "name" in index and index["name"].lower() == "sp":
+            index["prefix"] = "x"
+        if base is not None and "name" in base and base["name"].lower() == "zr":
+            base["prefix"] = "x"
+        if index is not None and "name" in index and index["name"].lower() == "zr":
             index["prefix"] = "x"
         valid_shift_ops = ["lsl", "uxtw", "uxtb", "sxtw"]
         if "index" in memory_address:
diff --git a/osaca/semantics/hw_model.py b/osaca/semantics/hw_model.py
index 6b84538..e03db3c 100755
--- a/osaca/semantics/hw_model.py
+++ b/osaca/semantics/hw_model.py
@@ -589,7 +589,7 @@ class MachineModel(object):
             return i_operand["class"] == "prfop"
         # condition
         if "condition" in operand:
-            if i_operand["ccode"] == self.WILDCARD:
+            if i_operand["class"] == "condition" and i_operand["ccode"] == self.WILDCARD:
                 return True
             return i_operand["class"] == "condition" and (
                 operand.get("condition", None) == i_operand.get("ccode", None).upper()