diff --git a/Port/Cortex-M/port_cmx.h b/Port/Cortex-M/port_cmx.h
index 55388b69..6a05a5d2 100644
--- a/Port/Cortex-M/port_cmx.h
+++ b/Port/Cortex-M/port_cmx.h
@@ -3,8 +3,8 @@
  * @file     port_cmx.h
  * @brief    CMSIS Cortex-M Core Port File
  * @author   迟凯峰
- * @version  V2.2.0
- * @date     2026.01.13
+ * @version  V2.2.1
+ * @date     2026.01.16
  ******************************************************************************/
 
 #ifndef __PORT_CMX_H
@@ -68,13 +68,14 @@ extern  void     mPendSV_FIFOHandler(void);
 #if (MCUCFG_PENDSVFIFO_MUTEX == 2)
 extern  void    *mPendSV_FIFO_X;
 extern  volatile bool m_sign_load;
+#define mPendSV_FIFO_rx r6
 
 /*
  * Arm Compiler 4/5
  */
 #if defined ( __CC_ARM )
 /* For Arm Compiler 4/5, CosyOS has already defined the register variable r6. */
-register void **mPendSV_FIFO_REGx __ASM("r6");
+register void **mPendSV_FIFO_REGx __ASM(sDefStr(mPendSV_FIFO_rx));
 
 /*
  * Arm Compiler 6.6 LTM / above 6.10.1 (armclang)
@@ -87,7 +88,7 @@ register void **mPendSV_FIFO_REGx __ASM("r6");
  */
 #elif defined ( __GNUC__ )
 /* For GNU Compiler, CosyOS has already defined the register variable r6. */
-__extension__ register void **mPendSV_FIFO_REGx __ASM("r6");
+__extension__ register void **mPendSV_FIFO_REGx __ASM(sDefStr(mPendSV_FIFO_rx));
 
 /*
  * IAR Compiler