Index: rom_api.h
===================================================================
--- /YC3121_SDK/fw/core/rom_api.h	(revision 570)
+++ /YC3121_SDK/fw/core/rom_api.h	(working copy)
@@ -2,13 +2,17 @@
 File Name    : yc3121.h
 Author       : Yichip
 Version      : V1.0
-Date         : 2019/12/13
+Date         : 2020/02/11
 Description  : rom fun information.
 */
 
 #ifndef __ROM_API_H__
 #define __ROM_API_H__
 
+/* TIMER */
+#define FUNC_DELAY_US_ADDR               (0x4238 + 1)
+#define FUNC_DELAY_MS_ADDR               (0x425c + 1)
+
 /* OTP */
 #define FUNC_INIT_OTP_ADDR               (0x442c + 1)
 #define FUNC_DEINIT_OTP_ADDR             (0x4480 + 1)