diff --git a/arch/csr/medelegh.yaml b/arch/csr/medelegh.yaml
index 271e198859..4a75e09e47 100644
--- a/arch/csr/medelegh.yaml
+++ b/arch/csr/medelegh.yaml
@@ -8,5 +8,7 @@ medelegh:
   base: 32
   description: |
     Alias of the upper 32 bits of `medeleg`.
-  definedBy: I
+  definedBy:
+    name: S
+    version: ">= 1.13"
   fields: {}
diff --git a/arch/csr/mseccfg.yaml b/arch/csr/mseccfg.yaml
index 7f90c9de3b..2cbc905e68 100644
--- a/arch/csr/mseccfg.yaml
+++ b/arch/csr/mseccfg.yaml
@@ -8,6 +8,6 @@ mseccfg:
   description: Machine Security Configuration
   definedBy:
     name: Sm
-    version: ">=1.12"
+    version: ">= 1.12"
   fields: {}
   
\ No newline at end of file
diff --git a/arch/csr/mseccfgh.yaml b/arch/csr/mseccfgh.yaml
index 6aa15924cb..80a5a721f6 100644
--- a/arch/csr/mseccfgh.yaml
+++ b/arch/csr/mseccfgh.yaml
@@ -8,6 +8,6 @@ mseccfgh:
   description: Machine Security Configuration
   definedBy:
     name: Sm
-    version: ">=1.12"
+    version: ">= 1.12"
   fields: {}
   
\ No newline at end of file
diff --git a/arch/csr/mstatush.yaml b/arch/csr/mstatush.yaml
index bf306ef997..eec243033b 100644
--- a/arch/csr/mstatush.yaml
+++ b/arch/csr/mstatush.yaml
@@ -7,7 +7,9 @@ mstatush:
   base: 32
   length: 32
   description: The mstatus register tracks and controls the hart's current operating state.
-  definedBy: Sm
+  definedBy:
+    name: Sm
+    version: ">= 1.12"
   fields:
     MPV:
       location: 7
diff --git a/backends/crd_doc/templates/crd.adoc.erb b/backends/crd_doc/templates/crd.adoc.erb
index 0a05769cb3..79580fbbaa 100644
--- a/backends/crd_doc/templates/crd.adoc.erb
+++ b/backends/crd_doc/templates/crd.adoc.erb
@@ -176,7 +176,7 @@ None
 == CSR Summary
 
 <%
-  csrs = crd.in_scope_extensions.map { |ext_crd| ext_crd.csrs }.flatten.uniq
+  csrs = crd.in_scope_ext_reqs.map { |ext_crd_req| ext_crd_req.csrs(crd.arch_def) }.flatten.uniq
 -%>
 
 === By Name
@@ -476,7 +476,7 @@ This instruction may result in the following synchronous exceptions:
 == CSR Details
 
 <%
-  csrs = crd.in_scope_extensions.map { |ext_crd| ext_crd.csrs }.flatten.uniq
+  csrs = crd.in_scope_ext_reqs.map { |ext_crd_req| ext_crd_req.csrs(crd.arch_def) }.flatten.uniq
   csrs.sort_by!(&:name)
 -%>
 
diff --git a/lib/arch_obj_models/extension.rb b/lib/arch_obj_models/extension.rb
index 4516d8d6f3..f8675e9425 100644
--- a/lib/arch_obj_models/extension.rb
+++ b/lib/arch_obj_models/extension.rb
@@ -422,15 +422,24 @@ def satisfying_versions(archdef)
   #   @param extension_version [ExtensionVersion] A specific extension version
   #   @return [Boolean] whether or not the extension_version meets this requirement
   # @overload
+  #   @param extension_requirement [ExtensionRequirement] A range of extension versions
+  #   @return [Boolean] whether or not extension_requirement is satisfied by this requirement
+  # @overload
   #   @param extension_name [#to_s] An extension name
   #   @param extension_name [#to_s] An extension version
   #   @return [Boolean] whether or not the extension_version meets this requirement
   def satisfied_by?(*args)
     if args.size == 1
-      raise ArgumentError, "Single argument must be an ExtensionVersion" unless args[0].is_a?(ExtensionVersion)
-
-      args[0].name == @name &&
-        @requirement.satisfied_by?(Gem::Version.new(args[0].version))
+      if args[0].is_a?(ExtensionVersion)
+        args[0].name == @name &&
+          @requirement.satisfied_by?(Gem::Version.new(args[0].version))
+      elsif args[0].is_a?(ExtensionRequirement)
+        satisfying_versions.all? do |ext_ver|
+          satified_by?(ext_ver)
+        end
+      else
+        raise ArgumentError, "Single argument must be an ExtensionVersion or ExtensionRquirement"
+      end
     elsif args.size == 2
       raise ArgumentError, "First parameter must be an extension name" unless args[0].respond_to?(:to_s)
       raise ArgumentError, "First parameter must be an extension version" unless args[1].respond_to?(:to_s)
@@ -442,6 +451,17 @@ def satisfied_by?(*args)
     end
   end
 
+  # @return [Array<Csr>] List of CSRs defined by any extension satisfying this requirement
+  def csrs(arch_def)
+    return @csrs unless @csrs.nil?
+
+    @csrs = arch_def.csrs.select do |csr|
+      satisfying_versions(arch_def).any? do |ext_ver|
+        csr.defined_by?(ext_ver)
+      end
+    end
+  end
+
   # sorts by name
   def <=>(other)
     raise ArgumentError, "ExtensionRequirements are only comparable to other extension requirements" unless other.is_a?(ExtensionRequirement)
diff --git a/lib/arch_obj_models/obj.rb b/lib/arch_obj_models/obj.rb
index 090bc2f501..7ed012adb8 100644
--- a/lib/arch_obj_models/obj.rb
+++ b/lib/arch_obj_models/obj.rb
@@ -151,6 +151,8 @@ def defined_by?(*args)
 
   # @return [SchemaCondition] Extension(s) that define the instruction. If *any* requirement is met, the instruction is defined.
   def defined_by
+    raise "ERROR: definedBy is nul for #{name}" if @data["definedBy"].nil?
+
     SchemaCondition.new(@data["definedBy"])
   end