diff --git a/src/main.c b/src/main.c
index ab9b576..e2a9371 100644
--- a/src/main.c
+++ b/src/main.c
@@ -79,8 +79,8 @@ int main(int argc, char **argv) {
     printf("[recvfrom]:%s\n", buffer);
 
     if (strcmp(buffer, "ok") == 0) {
+        usleep(2000000);
         printf("[mmap]:wr...\n");
-        sleep(1);
         mapped_addr = (volatile uint32_t *)ucp4008_ctrl_mmap_base;
         *mapped_addr = 0xA5A55A5A;
         munmap(ucp4008_ctrl_mmap_base, PAGE_SIZE);