diff --git a/hw/application_fpga/core/tk1/tb/tb_tk1.v b/hw/application_fpga/core/tk1/tb/tb_tk1.v
index 7624c27..871456d 100644
--- a/hw/application_fpga/core/tk1/tb/tb_tk1.v
+++ b/hw/application_fpga/core/tk1/tb/tb_tk1.v
@@ -478,40 +478,6 @@ module tb_tk1 ();
   endtask  // test3
 
 
-  //----------------------------------------------------------------
-  // test4()
-  // Write and read blake2s entry point.
-  //----------------------------------------------------------------
-  task test4;
-    begin
-      tc_ctr = tc_ctr + 1;
-
-      $display("");
-      $display("--- test4: Write and read blake2s entry point in fw mode started.");
-      $display("--- test4: Reset DUT to switch to fw mode.");
-      reset_dut();
-
-      $display("--- test4: Write Blake2s entry point.");
-      write_word(ADDR_BLAKE2S, 32'hcafebabe);
-
-      $display("--- test4: Read Blake2s entry point.");
-      read_check_word(ADDR_BLAKE2S, 32'hcafebabe);
-
-      $display("--- test4: Switch to app mode.");
-      write_word(ADDR_SYSTEM_MODE_CTRL, 32'hf00ff00f);
-
-      $display("--- test4: Write Blake2s entry point again.");
-      write_word(ADDR_BLAKE2S, 32'hdeadbeef);
-
-      $display("--- test4: Read Blake2s entry point again");
-      read_check_word(ADDR_BLAKE2S, 32'hcafebabe);
-
-      $display("--- test4: completed.");
-      $display("");
-    end
-  endtask  // test4
-
-
   //----------------------------------------------------------------
   // test5()
   // Write and read APP start address end size.
@@ -755,7 +721,6 @@ module tb_tk1 ();
     test1();
     test2();
     test3();
-    test4();
     test5();
     test6();
     test7();