Merge pull request #11157 from mprse/us_ticker_freq_fix

Relax us ticker frequency requirement + test update

TESTS/mbed_hal/us_ticker/main.cpp

@@ -32,7 +32,17 @@ void us_ticker_info_test()
     const ticker_info_t *p_ticker_info = us_ticker_get_info();
 
     TEST_ASSERT(p_ticker_info->frequency >= 250000);
+
+    switch (p_ticker_info->bits) {
+        case 32:
+            TEST_ASSERT(p_ticker_info->frequency <= 100000000);
+            break;
+
+        default:
             TEST_ASSERT(p_ticker_info->frequency <= 8000000);
+            break;
+    }
+
     TEST_ASSERT(p_ticker_info->bits >= 16);
 
 #ifdef US_TICKER_PERIOD_NUM

TESTS/mbed_hal/us_ticker/us_ticker_api_tests.h

@@ -31,7 +31,10 @@ extern "C" {
  *
  * Given ticker is available.
  * When ticker information data is obtained.
- * Then ticker information indicate that frequency between 250KHz and 8MHz and the counter is at least 16 bits wide.
+ * Then ticker information indicate that:
+ * - counter frequency is between 250KHz and 8MHz for counters which are less than 32 bits wide
+ * - counter frequency is up to 100MHz for counters which are 32 bits wide
+ * - the counter is at least 16 bits wide.
  */
 void us_ticker_info_test(void);
 

hal/us_ticker_api.h

@@ -32,7 +32,8 @@ extern "C" {
  * Low level interface to the microsecond ticker of a target
  *
  * # Defined behavior
- * * Has a reported frequency between 250KHz and 8MHz - Verified by test ::us_ticker_info_test
+ * * Has a reported frequency between 250KHz and 8MHz for counters which are less than 32 bits wide - Verified by test ::us_ticker_info_test
+ * * Has a reported frequency up to 100MHz for counters which are 32 bits wide - Verified by test ::us_ticker_info_test
  * * Has a counter that is at least 16 bits wide - Verified by test ::us_ticker_info_test
  * * All behavior defined by the @ref hal_ticker_shared "ticker specification"
  *