Replace the read back of the software interrupt register with barrier instructions (CCS/RM48/TMS570).

FreeRTOS/Source/portable/CCS/ARM_Cortex-R4/portmacro.h

@@ -56,19 +56,19 @@
     ***************************************************************************
 
 
-    http://www.FreeRTOS.org - Documentation, books, training, latest versions, 
+    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
     license and Real Time Engineers Ltd. contact details.
 
     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
     including FreeRTOS+Trace - an indispensable productivity tool, and our new
     fully thread aware and reentrant UDP/IP stack.
 
-    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High 
+    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
-    Integrity Systems, who sell the code with commercial support, 
+    Integrity Systems, who sell the code with commercial support,
     indemnification and middleware, under the OpenRTOS brand.
-    
+
-    http://www.SafeRTOS.com - High Integrity Systems also provide a safety 
+    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
-    engineered and independently SIL3 certified version for use in safety and 
+    engineered and independently SIL3 certified version for use in safety and
     mission critical applications that require provable dependability.
 */
 
@@ -105,7 +105,7 @@
 
 /* Architecture specifics. */
 #define portSTACK_GROWTH    (-1)
-#define portTICK_RATE_MS    ((portTickType) 1000 / configTICK_RATE_HZ)		
+#define portTICK_RATE_MS    ((portTickType) 1000 / configTICK_RATE_HZ)
 #define portBYTE_ALIGNMENT  8
 
 /* Critical section handling. */
@@ -122,7 +122,7 @@ extern void vPortYield( void );
 #define portYIELD()             	vPortYield()
 #define portSYS_SSIR1_REG			( * ( ( volatile unsigned long * ) 0xFFFFFFB0 ) )
 #define portSYS_SSIR1_SSKEY			( 0x7500UL )
-#define portYIELD_WITHIN_API()		{ portSYS_SSIR1_REG = portSYS_SSIR1_SSKEY;  ( void ) portSYS_SSIR1_REG; }
+#define portYIELD_WITHIN_API()		{ portSYS_SSIR1_REG = portSYS_SSIR1_SSKEY;  asm( " DSB " ); asm( " ISB " ); }
 #define portYIELD_FROM_ISR( x )		if( x != pdFALSE ){ portSYS_SSIR1_REG = portSYS_SSIR1_SSKEY;  ( void ) portSYS_SSIR1_REG; }
 
 /* Architecture specific optimisations. */