diff --git a/GorgonMeducer.perf_counter.pdsc b/GorgonMeducer.perf_counter.pdsc
index e846d51..313c0a3 100644
--- a/GorgonMeducer.perf_counter.pdsc
+++ b/GorgonMeducer.perf_counter.pdsc
@@ -16,9 +16,10 @@
   <repository type="git">https://github.com/GorgonMeducer/perf_counter.git</repository>
   
   <releases>
-    <!--automatically generated content, please do not modify -->
-    <release version="9.9.9" tag="9.9.9">
-      Active development ...
+    <release date="2024-03-12" version="2.3.1" tag="v2.3.1" url="https://github.com/GorgonMeducer/perf_counter/releases/download/v2.3.1/GorgonMeducer.perf_counter.2.3.1.pack">
+      Release v2.3.1
+      - Fixed PMU-SysTick-overflow-miscounting issue
+      - Other minor changes.
     </release>
     <release date="2024-02-28" version="2.3.0" tag="v2.3.0" url="https://github.com/GorgonMeducer/perf_counter/releases/download/v2.3.0/GorgonMeducer.perf_counter.2.3.0.pack">
       Release v2.3.0
diff --git a/cmsis-pack/GorgonMeducer.perf_counter.2.3.0.pack b/cmsis-pack/GorgonMeducer.perf_counter.2.3.1.pack
similarity index 90%
rename from cmsis-pack/GorgonMeducer.perf_counter.2.3.0.pack
rename to cmsis-pack/GorgonMeducer.perf_counter.2.3.1.pack
index 964fa66..6234908 100644
Binary files a/cmsis-pack/GorgonMeducer.perf_counter.2.3.0.pack and b/cmsis-pack/GorgonMeducer.perf_counter.2.3.1.pack differ
diff --git a/cmsis-pack/GorgonMeducer.perf_counter.pdsc b/cmsis-pack/GorgonMeducer.perf_counter.pdsc
index 851b11c..313c0a3 100644
--- a/cmsis-pack/GorgonMeducer.perf_counter.pdsc
+++ b/cmsis-pack/GorgonMeducer.perf_counter.pdsc
@@ -16,7 +16,12 @@
   <repository type="git">https://github.com/GorgonMeducer/perf_counter.git</repository>
   
   <releases>
-    <release version="2.3.0" date="2024-02-28" tag="v2.3.0" url="https://github.com/GorgonMeducer/perf_counter/releases/download/v2.3.0/GorgonMeducer.perf_counter.2.3.0.pack">
+    <release date="2024-03-12" version="2.3.1" tag="v2.3.1" url="https://github.com/GorgonMeducer/perf_counter/releases/download/v2.3.1/GorgonMeducer.perf_counter.2.3.1.pack">
+      Release v2.3.1
+      - Fixed PMU-SysTick-overflow-miscounting issue
+      - Other minor changes.
+    </release>
+    <release date="2024-02-28" version="2.3.0" tag="v2.3.0" url="https://github.com/GorgonMeducer/perf_counter/releases/download/v2.3.0/GorgonMeducer.perf_counter.2.3.0.pack">
       Release v2.3.0
       - Support porting to a different architecture
       - Support Armv8.1-m PMU
@@ -212,12 +217,7 @@
             <require condition="Armv8-M Processors"/>
         </condition>
         
-        <condition id="Cortex-M Arm GCC CMSIS-CORE">
-            <description>Compile Cortex-M Processors with GNU Tools for Arm Embedded Processors.</description>
-            <require condition="Arm GCC"/>
-            <require condition="Cortex-M Processors"/>
-            <require condition="CMSIS-CORE"/>
-        </condition>
+
         <condition id="Cortex-M Arm Compiler CMSIS-CORE">
             <description>Compile Cortex-M Processors with GNU Tools for Arm Embedded Processors.</description>
             <require condition="Arm Compiler"/>
@@ -225,19 +225,35 @@
             <require condition="CMSIS-CORE"/>
         </condition>
         
-        <condition id="Previous Generation Cortex-M Arm Compiler CMSIS-CORE">
+        <condition id="Default Porting">
+            <description>Reject PMU and other portings</description>
+            <deny Cclass="Utilities" Cgroup="perf_counter" Csub="Porting" Cvariant="PMU" />
+            <deny Cclass="Utilities" Cgroup="perf_counter" Csub="Porting" Cvariant="User Defined" />
+        </condition>
+        
+        <condition id="Previous Generation Cortex-M Arm Compiler CMSIS-CORE Default Porting">
             <description>Compile Cortex-M Processors with GNU Tools for Arm Embedded Processors.</description>
             <require condition="Arm Compiler"/>
             <require condition="Previous Generation Cortex-M Processors"/>
             <require condition="CMSIS-CORE"/>
+            <require condition="Default Porting"/>
         </condition>
-        <condition id="Armv8-M Arm Compiler CMSIS-CORE">
+        
+        <condition id="Armv8-M Arm Compiler CMSIS-CORE Default Porting">
             <description>Compile Cortex-M Processors with GNU Tools for Arm Embedded Processors.</description>
             <require condition="Arm Compiler"/>
             <require condition="Armv8-M Processors"/>
             <require condition="CMSIS-CORE"/>
+            <require condition="Default Porting"/>
         </condition>
         
+        <condition id="Cortex-M Arm GCC CMSIS-CORE Default Porting">
+            <description>Compile Cortex-M Processors with GNU Tools for Arm Embedded Processors.</description>
+            <require condition="Arm GCC"/>
+            <require condition="Cortex-M Processors"/>
+            <require condition="CMSIS-CORE"/>
+            <require condition="Default Porting"/>
+        </condition>
         
     </conditions>
   <!-- apis section (optional - for Application Programming Interface descriptions) -->
@@ -271,15 +287,15 @@
   -->
 
     <components>
-            <component Cclass="Utilities" Cversion="2.3.0" Cgroup="perf_counter" Csub="Core" Cvariant="Source" isDefaultVariant="true" condition="CMSIS-CORE">
+            <component Cclass="Utilities" Cversion="2.3.1" Cgroup="perf_counter" Csub="Core" Cvariant="Source" isDefaultVariant="true" condition="CMSIS-CORE">
               <description>A dedicated performance counter for Cortex-M systick.</description>
               <files>
                 <file category="header"         name="perf_counter.h"/>
                 <file category="sourceC"        name="perf_counter.c" />
                 <file category="sourceC"        name="perfc_port_default.c" />
-                <file category="sourceAsm"      name="systick_wrapper_ual.s"        condition="Previous Generation Cortex-M Arm Compiler CMSIS-CORE"/>
-                <file category="sourceAsm"      name="systick_wrapper_gcc.S"        condition="Cortex-M Arm GCC CMSIS-CORE"/>
-                <file category="sourceAsm"      name="systick_wrapper_gnu.s"        condition="Armv8-M Arm Compiler CMSIS-CORE"/>
+                <file category="sourceAsm"      name="systick_wrapper_ual.s"        condition="Previous Generation Cortex-M Arm Compiler CMSIS-CORE Default Porting"/>
+                <file category="sourceAsm"      name="systick_wrapper_gcc.S"        condition="Cortex-M Arm GCC CMSIS-CORE Default Porting"/>
+                <file category="sourceAsm"      name="systick_wrapper_gnu.s"        condition="Armv8-M Arm Compiler CMSIS-CORE Default Porting"/>
               </files>
               <RTE_Components_h>
 
@@ -292,7 +308,7 @@
               </Pre_Include_Global_h>
             </component>
 
-            <component Cclass="Utilities" Cversion="2.3.0" Cgroup="perf_counter" Csub="Core" Cvariant="SourceNoWrapper" isDefaultVariant="false" condition="CMSIS-CORE">
+            <component Cclass="Utilities" Cversion="2.3.1" Cgroup="perf_counter" Csub="Core" Cvariant="SourceNoWrapper" isDefaultVariant="false" condition="CMSIS-CORE">
               <description>A dedicated performance counter for Cortex-M systick.</description>
               <files>
                 <file category="header"         name="perf_counter.h"/>
@@ -305,7 +321,7 @@
               </RTE_Components_h>
             </component>
             
-            <component Cclass="Utilities" Cversion="1.0.2" Cgroup="perf_counter" Csub="Porting" Cvariant="User Defined" isDefaultVariant="false" condition="perf_counter">
+            <component Cclass="Utilities" Cversion="1.0.3" Cgroup="perf_counter" Csub="Porting" Cvariant="User Defined" isDefaultVariant="false" condition="perf_counter">
               <description>A user define system timer</description>
               <files>
                 <file category="sourceC"        name="template/perfc_port_user.c" attr="config"  version="1.0.2"/>
@@ -317,7 +333,7 @@
               </RTE_Components_h>
 
               <Pre_Include_Global_h>
-
+#define __PERFC_USE_PORTING__                           1
 #define __PERFC_USE_USER_CUSTOM_PORTING__               1
 #define __PERFC_CFG_DISABLE_DEFAULT_SYSTICK_PORTING__   1
 #define __PERFC_CFG_PORTING_INCLUDE__                   "perfc_port_user.h"
@@ -325,7 +341,7 @@
               </Pre_Include_Global_h>
             </component>
 
-            <component Cclass="Utilities" Cversion="1.1.0" Cgroup="perf_counter" Csub="Porting" Cvariant="PMU" isDefaultVariant="true" condition="PMU Devices">
+            <component Cclass="Utilities" Cversion="1.1.1" Cgroup="perf_counter" Csub="Porting" Cvariant="PMU" isDefaultVariant="true" condition="PMU Devices">
               <description>Using the Performande Monitor Unit</description>
               <files>
                 <file category="sourceC"        name="perfc_port_pmu.c"/>
@@ -337,7 +353,7 @@
               </RTE_Components_h>
 
               <Pre_Include_Global_h>
-
+#define __PERFC_USE_PORTING__                           1
 #define __PERFC_USE_PMU_PORTING__                       1
 #define __PERFC_CFG_DISABLE_DEFAULT_SYSTICK_PORTING__   1
 #define __PERFC_CFG_PORTING_INCLUDE__                   "perfc_port_pmu.h"
diff --git a/cmsis-pack/GorgonMeducer.pidx b/cmsis-pack/GorgonMeducer.pidx
index d4b6e3e..95dd877 100644
--- a/cmsis-pack/GorgonMeducer.pidx
+++ b/cmsis-pack/GorgonMeducer.pidx
@@ -2,8 +2,8 @@
 <index schemaVersion="1.0.0" xs:noNamespaceSchemaLocation="PackIndex.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance">
   <vendor>GorgonMeducer</vendor>
   <url>https://raw.githubusercontent.com/GorgonMeducer/perf_counter/CMSIS-Pack/cmsis-pack/</url>
-  <timestamp>2024-02-28</timestamp>
+  <timestamp>2024-03-12/timestamp>
   <pindex>
-    <pdsc url="https://raw.githubusercontent.com/GorgonMeducer/perf_counter/CMSIS-Pack/cmsis-pack/" vendor="GorgonMeducer" name="perf_counter" version="2.3.0"/>
+    <pdsc url="https://raw.githubusercontent.com/GorgonMeducer/perf_counter/CMSIS-Pack/cmsis-pack/" vendor="GorgonMeducer" name="perf_counter" version="2.3.1"/>
   </pindex>
 </index>