diff --git a/npc/.gitignore b/npc/.gitignore
deleted file mode 100644
index 7040bf9..0000000
--- a/npc/.gitignore
+++ /dev/null
@@ -1,12 +0,0 @@
-*.*
-*
-!*/
-!Makefile
-!*.mk
-!*.[cSh]
-!*.v
-!*.cc
-!*.cpp
-!.gitignore
-!README.md
-build/
diff --git a/npc/Makefile b/npc/Makefile
deleted file mode 100644
index 46469fa..0000000
--- a/npc/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-all:
-	@echo "Write this Makefile by your self."
-
-sim:
-	$(call git_commit, "sim RTL") # DO NOT REMOVE THIS LINE!!!
-	@echo "Write this Makefile by your self."
-
-include ../Makefile
diff --git a/npc/csrc/main.cpp b/npc/csrc/main.cpp
deleted file mode 100644
index 5e95ddc..0000000
--- a/npc/csrc/main.cpp
+++ /dev/null
@@ -1,6 +0,0 @@
-#include <stdio.h>
-
-int main() {
-  printf("Hello, ysyx!\n");
-  return 0;
-}
diff --git a/npc/vsrc/example.v b/npc/vsrc/example.v
deleted file mode 100644
index 536579a..0000000
--- a/npc/vsrc/example.v
+++ /dev/null
@@ -1,2 +0,0 @@
-module example();
-endmodule