diff --git a/System/os_handler.c b/System/os_handler.c
index 988a481..178cb5d 100644
--- a/System/os_handler.c
+++ b/System/os_handler.c
@@ -4,7 +4,7 @@
  * @brief    SysTick2_Handler and PendSV2_Handler
  * @author   迟凯峰
  * @version  V2.2.1
- * @date     2024.04.20
+ * @date     2024.04.21
  ******************************************************************************/
 
 #include "os_link.h"
@@ -744,14 +744,14 @@ void PendSV2_Handler(void) MCUCFG_PENDSV_ATTRIBUTE
 			#if SYSCFG_DEBUGGING == __ENABLED__
 			if(s_sign_taskmgr) mUsedTime_END;
 			#endif
+			mTaskStack_PUSH;
 			
 			#if SYSCFG_MCUCORE == 8051
 			#pragma asm
-			
 			EXTRN DATA (m_bsp_add)
 			EXTRN DATA (m_reg_add)
 			?STACK SEGMENT IDATA
-			
+			CLR C
 			MOV DPL, s_task_current+1
 			MOV DPH, s_task_current
 			MOV A, SP
@@ -760,7 +760,6 @@ void PendSV2_Handler(void) MCUCFG_PENDSV_ATTRIBUTE
 			SUBB A, #6
 			MOV R1, A
 			
-			CLR C
 			MOV A, s_task_current+1
 			ADD A, m_bsp_add
 			MOV DPL, A
@@ -811,11 +810,12 @@ LABLE_A1:	MOV A, @R0
 			MOV A, s_task_current+1
 			ADD A, m_reg_add
 			MOV DPL, A
-			CLR A
-			ADDC A, s_task_current
-			MOV DPH, A
+			MOV DPH, s_task_current
+			JNC LABLE_A2
+			INC DPH
+			CLR C
 			
-			MOV A, 0x00
+LABLE_A2:	MOV A, 0x00
 			MOVX @DPTR, A
 			INC DPTR
 			MOV A, 0x01
@@ -841,8 +841,6 @@ LABLE_A1:	MOV A, @R0
 			#endif
 			#pragma endasm
 			#endif
-			
-			mTaskStack_PUSH;
 		}
 		
 		/* 新任务出栈 */
@@ -854,14 +852,13 @@ LABLE_A1:	MOV A, @R0
 			
 			#if SYSCFG_MCUCORE == 8051
 			#pragma asm
-			
+			CLR C
 			MOV DPL, s_task_current+1
 			MOV DPH, s_task_current
 			MOVX A, @DPTR
 			SUBB A, #6
 			MOV R1, A
 			
-			CLR C
 			MOV A, s_task_current+1
 			ADD A, m_bsp_add
 			MOV DPL, A
@@ -905,11 +902,12 @@ LABLE_B1:	MOVX A, @DPTR
 			MOV A, s_task_current+1
 			ADD A, m_reg_add
 			MOV DPL, A
-			CLR A
-			ADDC A, s_task_current
-			MOV DPH, A
+			MOV DPH, s_task_current
+			JNC LABLE_B2
+			INC DPH
+			CLR C
 			
-			MOVX A, @DPTR
+LABLE_B2:	MOVX A, @DPTR
 			MOV 0x00, A
 			INC DPTR
 			MOVX A, @DPTR