diff --git a/release/aarch64/uart_read_test_main.out b/release/aarch64/uart_read_test_main.out
index 58bedf3..b50fcbd 100755
Binary files a/release/aarch64/uart_read_test_main.out and b/release/aarch64/uart_read_test_main.out differ
diff --git a/uart_read_test_main.cpp b/uart_read_test_main.cpp
index d9c1947..4566b51 100644
--- a/uart_read_test_main.cpp
+++ b/uart_read_test_main.cpp
@@ -68,7 +68,7 @@ int main(int argc, char *argv[]) {
     int ret1, ret2;
     ret1 = uartReceive(&dev, buf, 2 /*接收的字节数2-1*/);  // send the received text over UART
     if (ret1 != 0) {
-      printf("%x", buf[0]);
+      printf("0x%02x", buf[0]);
       i++;
       if (i % 20 == 0) {
         printf("\n");