diff --git a/ARM.CMSIS.pdsc b/ARM.CMSIS.pdsc
index 95aa55d..f15f333 100644
--- a/ARM.CMSIS.pdsc
+++ b/ARM.CMSIS.pdsc
@@ -8,8 +8,12 @@
   <url>http://www.keil.com/pack/</url>
 
   <releases>
-    <release version="5.5.0-dev3">
+    <release version="5.5.0-dev4">
       Active development ...
+      CMSIS-Core(M):
+       - Added generic Armv8.1-M Mainline device support.
+    </release>
+    <release version="5.5.0-dev3">
       CMSIS-Driver:
         - Added WiFi Driver API 1.0.0-beta
     </release>
@@ -639,6 +643,29 @@
         <compile header="Device/ARM/ARMv8MML/Include/ARMv8MML_DSP_DP.h" define="ARMv8MML_DSP_DP"/>
       </device>
     </family>
+    
+    <!-- ******************************  ARMv8.1-M Mainline  ****************************** -->
+    <family Dfamily="ARMv8.1-M Mainline" Dvendor="ARM:82">
+      <!--book name="Device/ARM/Documents/ARMv8MML_dgug.pdf"       title="ARMv8MML Device Generic Users Guide"/-->
+      <description>
+Armv8.1-M Mainline based device with TrustZone and MVE 
+      </description>
+      <!-- <debug svd="Device/ARM/SVD/ARMv8MML.svd"/> -->
+      <memory id="IROM1"                                start="0x00000000" size="0x00200000" startup="1" default="1"/>
+      <memory id="IROM2"                                start="0x00200000" size="0x00200000" startup="0" default="0"/>
+      <memory id="IRAM1"                                start="0x20000000" size="0x00020000" init   ="0" default="1"/>
+      <memory id="IRAM2"                                start="0x20200000" size="0x00020000" init   ="0" default="0"/>
+      <!--algorithm name="Device/ARM/Flash/NEW_DEVICE.FLM" start="0x00000000" size="0x00040000"             default="1"/-->
+
+   
+      <device Dname="ARMv81MML_DSP_DP_MVE_FP">
+        <processor Dcore="ARMV81MML" DcoreVersion="r0p0" Dfpu="DP_FPU" Dmpu="MPU" Dmve="FP_MVE" Ddsp="DSP" Dtz="TZ" Dendian="Configurable" Dclock="10000000"/>
+        <description>
+          Double Precision Vector Extensions, DSP Instructions, Double Precision Floating Point Unit, TrustZone
+        </description>
+        <compile header="Device/ARM/ARMv81MML/Include/ARMv81MML_DSP_DP_MVE_FP.h" define="ARMv81MML_DSP_DP_MVE_FP"/>
+      </device>   
+    </family>
 
     <!-- ******************************  Cortex-A5  ****************************** -->
     <family Dfamily="ARM Cortex A5" Dvendor="ARM:82">
@@ -873,6 +900,7 @@
       <description>Armv8-M architecture based device</description>
       <accept Dcore="ARMV8MBL"/>
       <accept Dcore="ARMV8MML"/>
+      <accept Dcore="ARMV81MML"/>
       <accept Dcore="Cortex-M23"/>
       <accept Dcore="Cortex-M33"/>
       <accept Dcore="Cortex-M35P"/>
@@ -1028,6 +1056,11 @@
       <require Dcore="ARMV8MML" Ddsp="DSP" Dfpu="SP_FPU"/>
     </condition>
 
+    <condition id="ARMv81MML">
+      <description>Armv8.1-M Mainline</description>
+      <require Dvendor="ARM:82" Dname="ARMv81MML*"/>   
+    </condition>
+
     <condition id="CA5_CA9">
       <description>Cortex-A5 or Cortex-A9 processor based device</description>
       <accept Dcore="Cortex-A5"/>
@@ -1445,7 +1478,7 @@
       <require condition="ARMv8MML_DSP_SP_ARMCC"/>
       <require Dendian="Little-endian"/>
     </condition>
-
+    
     <!-- GCC compiler -->
     <condition id="CA_GCC">
       <description>Cortex-A5, Cortex-A7 or Cortex-A9 processor based device for the GCC Compiler</description>
@@ -2395,6 +2428,12 @@
       <require condition="GCC"/>
     </condition>
 
+    <condition id="ARMv81MML CMSIS">
+      <description>Generic Armv8.1-M Mainline device startup and depends on CMSIS Core</description>
+      <require Dvendor="ARM:82" Dname="ARMv81MML*"/>
+      <require Cclass="CMSIS" Cgroup="CORE"/>
+    </condition>
+
     <condition id="ARMCA5 CMSIS">
       <description>Generic Arm Cortex-A5 device startup and depends on CMSIS Core</description>
       <require Dvendor="ARM:82" Dname="ARMCA5"/>
@@ -2497,8 +2536,8 @@
 
   <components>
     <!-- CMSIS-Core component -->
-    <component Cclass="CMSIS" Cgroup="CORE" Cversion="5.1.2"  condition="ARMv6_7_8-M Device" >
-      <description>CMSIS-CORE for Cortex-M, SC000, SC300, ARMv8-M</description>
+    <component Cclass="CMSIS" Cgroup="CORE" Cversion="5.1.3"  condition="ARMv6_7_8-M Device" >
+      <description>CMSIS-CORE for Cortex-M, SC000, SC300, ARMv8-M, ARMv8.1-M</description>
       <files>
         <!-- CPU independent -->
         <file category="doc"     name="CMSIS/Documentation/Core/html/index.html"/>
@@ -2509,7 +2548,7 @@
         <file category="sourceC" attr="template" condition="ARMv8-M TZ Device" name="CMSIS/Core/Template/ARMv8-M/tz_context.c" version="1.1.0" select="RTOS Context Management (TrustZone for ARMv8-M)" />
       </files>
     </component>
-
+   
     <component Cclass="CMSIS" Cgroup="CORE" Cversion="1.1.2"  condition="ARMv7-A Device" >
       <description>CMSIS-CORE for Cortex-A</description>
       <files>
@@ -2876,6 +2915,41 @@
       </files>
     </component>
 
+    <!-- ARMv81MML -->
+    <component Cclass="Device" Cgroup="Startup"                      Cversion="1.0.0" condition="ARMv81MML CMSIS">
+      <description>System and Startup for Generic Armv8.1-M Mainline device</description>
+      <files>
+        <!-- include folder / device header file -->
+        <file category="include"      name="Device/ARM/ARMv81MML/Include/"/>
+        <file category="header"       name="Device/ARM/ARMv81MML/Include/ARMv81MML_DSP_DP_MVE_FP.h"/>
+        <!-- startup / system file -->
+        <file category="sourceAsm"    name="Device/ARM/ARMv81MML/Source/ARM/startup_ARMv81MML.s"         version="1.0.0" attr="config" condition="ARMCC"/>
+        <file category="linkerScript" name="Device/ARM/ARMv81MML/Source/ARM/ARMv81MML.sct"               version="1.0.0" attr="config" condition="ARMCC"/>
+        <file category="sourceAsm"    name="Device/ARM/ARMv81MML/Source/GCC/startup_ARMv81MML.S"         version="1.0.0" attr="config" condition="GCC"/>
+        <file category="linkerScript" name="Device/ARM/ARMv81MML/Source/GCC/gcc_arm.ld"                  version="1.0.0" attr="config" condition="GCC"/>
+        <file category="sourceAsm"    name="Device/ARM/ARMv81MML/Source/IAR/startup_ARMv81MML.S"         version="1.0.0" attr="config" condition="IAR"/>
+        <file category="sourceC"      name="Device/ARM/ARMv81MML/Source/system_ARMv81MML.c"              version="1.0.0" attr="config"/>
+        <!-- SAU configuration -->
+        <file category="header"       name="Device/ARM/ARMv81MML/Include/Template/partition_ARMv81MML.h" version="1.0.0" attr="config" condition="ARMv8-M TZ Device"/>
+      </files>
+    </component>
+    <component Cclass="Device" Cgroup="Startup" Cvariant="C Startup" Cversion="1.0.0" condition="ARMv81MML CMSIS">
+      <description>System and Startup for Generic Armv8.1-M Mainline device</description>
+      <files>
+        <!-- include folder / device header file -->
+        <file category="include"      name="Device/ARM/ARMv81MML/Include/"/>
+        <!-- startup / system file -->
+        <file category="sourceC"      name="Device/ARM/ARMv81MML/Source/ARM/startup_ARMv81MML.c"         version="1.0.0" attr="config" condition="ARMCC"/>
+        <file category="linkerScript" name="Device/ARM/ARMv81MML/Source/ARM/ARMv81MML.sct"               version="1.0.0" attr="config" condition="ARMCC"/>
+        <file category="sourceC"      name="Device/ARM/ARMv81MML/Source/GCC/startup_ARMv81MML.c"         version="1.0.0" attr="config" condition="GCC"/>
+        <file category="linkerScript" name="Device/ARM/ARMv81MML/Source/GCC/gcc_arm.ld"                  version="1.0.0" attr="config" condition="GCC"/>
+        <file category="sourceC"      name="Device/ARM/ARMv81MML/Source/IAR/startup_ARMv81MML.c"         version="1.0.0" attr="config" condition="IAR"/>
+        <file category="sourceC"      name="Device/ARM/ARMv81MML/Source/system_ARMv81MML.c"              version="1.0.0" attr="config"/>
+        <!-- SAU configuration -->
+        <file category="header"       name="Device/ARM/ARMv81MML/Include/Template/partition_ARMv81MML.h" version="1.0.0" attr="config" condition="ARMv8-M TZ Device"/>
+      </files>
+    </component>
+    
     <!-- Cortex-A5 -->
     <component Cclass="Device" Cgroup="Startup"                      Cversion="1.0.0" condition="ARMCA5 CMSIS">
       <description>System and Startup for Generic Arm Cortex-A5 device</description>