diff --git a/CMakeLists.txt b/CMakeLists.txt
index ea5af47..224d2a9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,7 @@ option(TIM_VX_CODE_COVERAGE             "Run code coverage with gconv(gcc only"
 option(TIM_VX_USE_EXTERNAL_OVXLIB       "Use external OVXLIB"                   OFF)
 option(TIM_VX_BUILD_EXAMPLES            "Build demos show general usage"        OFF)
 option(TIM_VX_ENABLE_VIPLITE            "Enable lite driver api support"        OFF)
+option(TIM_VX_ENABLE_40BIT              "Enable large memory support"           OFF)
 
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
@@ -24,6 +25,11 @@ if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
   set(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}/install" CACHE PATH "" FORCE)
 endif()
 
+if(${TIM_VX_ENABLE_40BIT})
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DVSI_40BIT_VA_SUPPORT")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DVSI_40BIT_VA_SUPPORT")
+endif()
+
 set(CMAKE_C_VISIBILITY_PRESET hidden)
 
 if(EXTERNAL_VIV_SDK AND EXISTS ${EXTERNAL_VIV_SDK})
diff --git a/README.md b/README.md
index 4488921..e92cebe 100644
--- a/README.md
+++ b/README.md
@@ -58,8 +58,9 @@ cmake options:
 |`TIM_VX_USE_EXTERNAL_OVXLIB`| Replace internal with a prebuilt libovxlib library | OFF |
 |`OVXLIB_LIB`|full path to libovxlib.so include so name, required if `TIM_VX_USE_EXTERNAL_OVXLIB`=ON | Not set |
 |`OVXLIB_INC`|ovxlib's include path, required if `TIM_VX_USE_EXTERNAL_OVXLIB`=ON| Not set |
-|`EXTERNAL_VIV_SDK`| Give external vivante openvx driver libraries | OFF |
+|`EXTERNAL_VIV_SDK`| Give external vivante openvx driver libraries | Not set|
 |`TIM_VX_BUILD_EXAMPLES`| Build example applications | OFF |
+|`TIM_VX_ENABLE_40BIT` | Enable large memory (over 4G) support in NPU driver | OFF |
 
 ----
 run unit test:
diff --git a/src/tim/vx/tensor.cc b/src/tim/vx/tensor.cc
index 5979b43..0d0dc7f 100644
--- a/src/tim/vx/tensor.cc
+++ b/src/tim/vx/tensor.cc
@@ -187,6 +187,7 @@ bool TensorImpl::Init() {
 
   PackTensorDtype(spec_, &attr.dtype);
 
+#ifndef VSI_40BIT_VA_SUPPORT
   if ((spec_.attr_ & TensorAttribute::INPUT) ||
       (spec_.attr_ & TensorAttribute::OUTPUT)) {
 #ifdef VX_CREATE_TENSOR_SUPPORT_PHYSICAL
@@ -209,7 +210,9 @@ bool TensorImpl::Init() {
     }
 #endif
 
-  } else {
+  } else
+#endif
+  {
     id_ = vsi_nn_AddTensor(graph_->graph(), VSI_NN_TENSOR_ID_AUTO, &attr,
                            nullptr);
   }