diff --git a/Makefile b/Makefile
index e64aa4e..26eda9d 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,7 @@ SRCS := \
   CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_pwr.c \
   CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_sys.c \
   CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_timer0.c \
+  CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_timer1.c \
   CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_timer3.c \
   CH5xx_ble_firmware_library/RVMSIS/core_riscv.c \
   CH5xx_ble_firmware_library/Startup/startup_CH583.S \
diff --git a/src/main.c b/src/main.c
index 3c3ebe9..2a7bde6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -45,6 +45,9 @@ int main()
     TMR0_ITCfg(ENABLE, TMR0_3_IT_CYC_END);
     PFIC_EnableIRQ(TMR0_IRQn);
 
+    TMR1_TimerInit((FREQ_SYS / 1000));
+    TMR1_ITCfg(ENABLE, TMR0_3_IT_CYC_END);
+
     TMR3_TimerInit(FREQ_SYS / 200);
     TMR3_ITCfg(ENABLE, TMR0_3_IT_CYC_END);
     PFIC_EnableIRQ(TMR3_IRQn);
@@ -58,6 +61,9 @@ int main()
 
     screen_push(&badge_screen);
 
+    // set SEVONPEND
+    PFIC->SCTLR |= (1 << 4);
+
     while (1) {
         WWDG_SetCounter(0x7F);
         static int btldr_timer = 0;
@@ -108,6 +114,11 @@ int main()
         TMOS_SystemProcess();
         cdc_tick();
         hid_tick();
-        DelayMs(1);
+
+        while (!TMR1_GetITFlag(TMR0_3_IT_CYC_END)) {
+            __SEV();
+            __asm__ volatile("wfi");
+        }
+        TMR1_ClearITFlag(TMR0_3_IT_CYC_END);
     }
 }