Minor change to SAM4L_low_power_tick_management.c to ensure the alarm value cannot be set to zero.

FreeRTOS/Demo/CORTEX_M4_ATSAM4L_Atmel_Studio/FreeRTOS_Demo.cproj

@@ -208,7 +208,7 @@
   <armgcc.compiler.optimization.OtherFlags>-fdata-sections</armgcc.compiler.optimization.OtherFlags>
   <armgcc.compiler.optimization.PrepareFunctionsForGarbageCollection>True</armgcc.compiler.optimization.PrepareFunctionsForGarbageCollection>
   <armgcc.compiler.warnings.AllWarnings>True</armgcc.compiler.warnings.AllWarnings>
-  <armgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.compiler.miscellaneous.OtherFlags>
+  <armgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.compiler.miscellaneous.OtherFlags>
   <armgcc.linker.libraries.Libraries>
     <ListValues>
       <Value>arm_cortexM4l_math</Value>
@@ -223,7 +223,7 @@
   </armgcc.linker.libraries.LibrarySearchPaths>
   <armgcc.linker.optimization.GarbageCollectUnusedSections>True</armgcc.linker.optimization.GarbageCollectUnusedSections>
   <armgcc.linker.miscellaneous.LinkerFlags>-T../src/asf/sam/utils/linker_scripts/sam4l/sam4l4/gcc/flash.ld -Wl,--cref -Wl,--entry=Reset_Handler -mthumb</armgcc.linker.miscellaneous.LinkerFlags>
-  <armgcc.assembler.general.AssemblerFlags>-D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.assembler.general.AssemblerFlags>
+  <armgcc.assembler.general.AssemblerFlags>-D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.assembler.general.AssemblerFlags>
   <armgcc.assembler.general.IncludePaths>
     <ListValues>
       <Value>../src/asf/sam/utils/preprocessor</Value>
@@ -252,7 +252,7 @@
       <Value>%24(ToolchainDir)\..\..\CMSIS_Atmel\Device\ATMEL\sam4l\include</Value>
     </ListValues>
   </armgcc.assembler.general.IncludePaths>
-  <armgcc.preprocessingassembler.general.AssemblerFlags>-DARM_MATH_CM4=true -DBOARD=SAM4L_EK -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.preprocessingassembler.general.AssemblerFlags>
+  <armgcc.preprocessingassembler.general.AssemblerFlags>-DARM_MATH_CM4=true -DBOARD=SAM4L_EK -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.preprocessingassembler.general.AssemblerFlags>
   <armgcc.preprocessingassembler.general.IncludePaths>
     <ListValues>
       <Value>../src/asf/sam/utils/preprocessor</Value>
@@ -332,7 +332,7 @@
   <armgcc.compiler.optimization.PrepareFunctionsForGarbageCollection>True</armgcc.compiler.optimization.PrepareFunctionsForGarbageCollection>
   <armgcc.compiler.optimization.DebugLevel>Maximum (-g3)</armgcc.compiler.optimization.DebugLevel>
   <armgcc.compiler.warnings.AllWarnings>True</armgcc.compiler.warnings.AllWarnings>
-  <armgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -Wmissing-field-initializers -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.compiler.miscellaneous.OtherFlags>
+  <armgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -Wmissing-field-initializers -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.compiler.miscellaneous.OtherFlags>
   <armgcc.linker.libraries.Libraries>
     <ListValues>
       <Value>libm</Value>
@@ -346,7 +346,7 @@
   </armgcc.linker.libraries.LibrarySearchPaths>
   <armgcc.linker.optimization.GarbageCollectUnusedSections>True</armgcc.linker.optimization.GarbageCollectUnusedSections>
   <armgcc.linker.miscellaneous.LinkerFlags>-T../src/asf/sam/utils/linker_scripts/sam4l/sam4l4/gcc/flash.ld -Wl,--cref -Wl,--entry=Reset_Handler -mthumb</armgcc.linker.miscellaneous.LinkerFlags>
-  <armgcc.assembler.general.AssemblerFlags>-D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.assembler.general.AssemblerFlags>
+  <armgcc.assembler.general.AssemblerFlags>-D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.assembler.general.AssemblerFlags>
   <armgcc.assembler.general.IncludePaths>
     <ListValues>
       <Value>../src/asf/sam/utils/preprocessor</Value>
@@ -376,7 +376,7 @@
     </ListValues>
   </armgcc.assembler.general.IncludePaths>
   <armgcc.assembler.debugging.DebugLevel>Default (-g)</armgcc.assembler.debugging.DebugLevel>
-  <armgcc.preprocessingassembler.general.AssemblerFlags>-DARM_MATH_CM4=true -DBOARD=SAM4L_EK -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.preprocessingassembler.general.AssemblerFlags>
+  <armgcc.preprocessingassembler.general.AssemblerFlags>-DARM_MATH_CM4=true -DBOARD=SAM4L_EK -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__ -D__ATSAM4LC4C__</armgcc.preprocessingassembler.general.AssemblerFlags>
   <armgcc.preprocessingassembler.general.IncludePaths>
     <ListValues>
       <Value>../src/asf/sam/utils/preprocessor</Value>

FreeRTOS/Demo/CORTEX_M4_ATSAM4L_Atmel_Studio/src/SAM4L_low_power_tick_management.c

@@ -248,7 +248,7 @@ static void prvEnableAST( void )
 /*-----------------------------------------------------------*/
 
 /* Override the default definition of vPortSuppressTicksAndSleep() that is weakly
-defined in the FreeRTOS Cortex-M3 port layet with a version that manages the
+defined in the FreeRTOS Cortex-M3 port layer with a version that manages the
 asynchronous timer (AST), as the tick is generated from the low power AST and
 not the SysTick as would normally be the case on a Cortex-M. */
 void vPortSuppressTicksAndSleep( portTickType xExpectedIdleTime )
@@ -372,6 +372,12 @@ enum sleepmgr_mode xSleepMode;
 			/* The alarm value is set to whatever fraction of a single tick
 			period remains. */
 			ulAlarmValue = ast_read_counter_value( AST ) - ( ulCompleteTickPeriods * ulAlarmValueForOneTick );
+			if( ulAlarmValue == 0 )
+			{
+				/* There is no fraction remaining. */
+				ulAlarmValue = ulAlarmValueForOneTick;
+				ulCompleteTickPeriods++;
+			}
 			ast_write_alarm0_value( AST, ulAlarmValue );
 		}