diff --git a/configs/sama5d3-xplained/README.txt b/configs/sama5d3-xplained/README.txt
index 85342306d61..570821c8194 100644
--- a/configs/sama5d3-xplained/README.txt
+++ b/configs/sama5d3-xplained/README.txt
@@ -2378,6 +2378,7 @@ Tickless OS
 
     RTOS Features -> Clocks and Timers
       CONFIG_SCHED_TICKLESS=y          : Configures the RTOS in tickless mode
+      CONFIG_SCHED_TICKLESS_ALARM=n    : (option not implemented)
 
     System Type -> SAMA5 Peripheral Support
       CONFIG_SAMA5_TC0=y               : Enable TC0 (TC channels 0-3
@@ -2410,7 +2411,8 @@ Tickless OS
   from 0xffffffff to zero).  So we could potentially just set the compare
   at the number of ticks you want PLUS the current value of timer.  Then
   you could have both with a single timer:  An interval timer and a free-
-  running counter with the same timer!
+  running counter with the same timer!  In this case, you would want to
+  to set CONFIG_SCHED_TICKLESS_ALARM in the NuttX configuration.
 
   Patches are welcome!
 
diff --git a/configs/sama5d3x-ek/README.txt b/configs/sama5d3x-ek/README.txt
index 3b4de458f5e..8f1978b67b3 100644
--- a/configs/sama5d3x-ek/README.txt
+++ b/configs/sama5d3x-ek/README.txt
@@ -2694,6 +2694,7 @@ Tickless OS
 
     RTOS Features -> Clocks and Timers
       CONFIG_SCHED_TICKLESS=y          : Configures the RTOS in tickless mode
+      CONFIG_SCHED_TICKLESS_ALARM=n    : (option not implemented)
 
     System Type -> SAMA5 Peripheral Support
       CONFIG_SAMA5_TC0=y               : Enable TC0 (TC channels 0-3
@@ -2723,10 +2724,11 @@ Tickless OS
   32-bit counters with the capability to generate a compare interrupt when
   the timer matches a compare value but also to continue counting without
   stopping (giving another, different interrupt when the timer rolls over
-  from 0xffffffff to zero).  So we could potentially just set the compare
+  from 0xffffffff to zero).  So we could potentially used the just set the compare
   at the number of ticks you want PLUS the current value of timer.  Then
   you could have both with a single timer:  An interval timer and a free-
-  running counter with the same timer!
+  running counter with the same timer!  In this case, you would want to
+  to set CONFIG_SCHED_TICKLESS_ALARM in the NuttX configuration.
 
   Patches are welcome!
 
diff --git a/configs/sama5d4-ek/README.txt b/configs/sama5d4-ek/README.txt
index 2ee7d8b7b2a..94371e09f42 100644
--- a/configs/sama5d4-ek/README.txt
+++ b/configs/sama5d4-ek/README.txt
@@ -3158,6 +3158,7 @@ Tickless OS
 
     RTOS Features -> Clocks and Timers
       CONFIG_SCHED_TICKLESS=y          : Configures the RTOS in tickless mode
+      CONFIG_SCHED_TICKLESS_ALARM=n    : (option not implemented)
 
     System Type -> SAMA5 Peripheral Support
       CONFIG_SAMA5_TC0=y               : Enable TC0 (TC channels 0-3
@@ -3196,7 +3197,8 @@ Tickless OS
   from 0xffffffff to zero).  So we could potentially just set the compare
   at the number of ticks you want PLUS the current value of timer.  Then
   you could have both with a single timer:  An interval timer and a free-
-  running counter with the same timer!
+  running counter with the same timer!  In this case, you would want to
+  to set CONFIG_SCHED_TICKLESS_ALARM in the NuttX configuration.
 
   Patches are welcome!