diff --git a/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/AppDelegate.swift b/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/AppDelegate.swift
index 29730fd3b6209f27bf489d71fa0ada72c9c7db58..7817befaedf1aff04b75abd39cc6f7f06bc935d3 100644
--- a/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/AppDelegate.swift
+++ b/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/AppDelegate.swift
@@ -1,11 +1,11 @@
 /* Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
- 
+
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
- 
+
  http://www.apache.org/licenses/LICENSE-2.0
- 
+
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -16,35 +16,35 @@ import UIKit
 
 @UIApplicationMain
 class AppDelegate: UIResponder, UIApplicationDelegate {
-    
+
     var window: UIWindow?
-    
+
     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
         // Override point for customization after application launch.
         return true
     }
-    
+
     func applicationWillResignActive(_ application: UIApplication) {
         // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
         // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
     }
-    
+
     func applicationDidEnterBackground(_ application: UIApplication) {
         // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
         // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
     }
-    
+
     func applicationWillEnterForeground(_ application: UIApplication) {
         // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
     }
-    
+
     func applicationDidBecomeActive(_ application: UIApplication) {
         // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
     }
-    
+
     func applicationWillTerminate(_ application: UIApplication) {
         // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
     }
-    
-    
+
+
 }
diff --git a/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/ViewController.swift b/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/ViewController.swift
index 4c5886c7c1d8504d418c958de4dfdd4240303529..052cac90d7793e0f07c049b2d64879447e363695 100644
--- a/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/ViewController.swift
+++ b/metal/paddle-mobile-unit-test/paddle-mobile-unit-test/ViewController.swift
@@ -1,11 +1,11 @@
 /* Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
- 
+
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
- 
+
  http://www.apache.org/licenses/LICENSE-2.0
- 
+
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -31,5 +31,5 @@ class ViewController: UIViewController {
         //        test.testTranspose()
         print(" done ")
     }
-    
+
 }
diff --git a/src/operators/kernel/fpga/V1/fetch_kernel.cpp b/src/operators/kernel/fpga/V1/fetch_kernel.cpp
index 056e18b29fbe8a85000983289f0e36b5c6d78357..54fd12bfd32b5bb641ddb2e82aba6835001ba2ed 100644
--- a/src/operators/kernel/fpga/V1/fetch_kernel.cpp
+++ b/src/operators/kernel/fpga/V1/fetch_kernel.cpp
@@ -11,9 +11,7 @@ distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License. */
-
 #include "operators/kernel/fetch_kernel.h"
-
 namespace paddle_mobile {
 namespace operators {
 
@@ -35,7 +33,7 @@ bool FetchKernel<FPGA, float>::Init(FetchParam<FPGA> *param) {
   args.input_layout_type = fpga::LAYOUT_CHW;
   args.output_layout_type = fpga::LAYOUT_HWC;
   args.image.address = input->data<half>();
-  args.image.channels = (uint32_t)product(input->dims());
+  args.image.channels = (uint32_t)(input->fpga_data_num);
   args.image.height = 1;
   args.image.width = 1;
   args.image.pad_height = 0;
@@ -68,13 +66,10 @@ void FetchKernel<FPGA, float>::Compute(const FetchParam<FPGA> &param) {
   auto outC = param.Out()->dims()[1];
   auto outH = param.Out()->dims()[2];
   auto outW = param.Out()->dims()[3];
-  fpga::fpga_invalidate(param.fpga_bypass_args.output.address,
-                        outH *
-                            (paddle_mobile::fpga::align_to_x(outC * outW, 16)) *
-                            sizeof(float));
-
   float *outdata_ptr =
       reinterpret_cast<float *>(param.fpga_bypass_args.output.address);
+  fpga::fpga_invalidate(param.fpga_bypass_args.output.address,
+                        param.Out()->fpga_data_num * sizeof(float));
   float *data_tmp =
       reinterpret_cast<float *>(malloc(outC * outH * outW * sizeof(float)));
   dealign(outdata_ptr, data_tmp, outC, outH, outW);