SPRZ447E July   2017  – July 2024 AM5746 , AM5748 , AM5749

 

  1.   1
  2. 1Introduction
    1.     Related Documentation
    2.     Trademarks
    3.     Modules Impacted
  3. 2Silicon Advisories
    1.     Revisions SR 1.0 - Advisories List
    2.     i202
    3.     i378
    4.     i631
    5.     i694
    6.     i698
    7.     i699
    8.     i709
    9.     i727
    10.     i729
    11.     i734
    12.     i767
    13.     i782
    14.     i783
    15.     i802
    16.     i803
    17.     i807
    18.     i808
    19.     i809
    20.     i810
    21.     i813
    22.     i814
    23.     i815
    24.     i818
    25.     i819
    26.     i820
    27.     i824
    28.     i826
    29.     i829
    30.     i834
    31.     i849
    32.     i856
    33.     i862
    34.     i863
    35.     i869
    36.     i870
    37.     i871
    38.     i872
    39.     i874
    40.     i878
    41.     i879
    42.     i883
    43.     i889
    44.     i890
    45.     i893
    46.     i896
    47.     i897
    48.     i898
    49.     i899
    50.     i900
    51.     i903
    52.     i904
    53.     i916
    54.     i929
    55.     i930
    56.     i932
    57.     i933
    58.     i936
    59.     i940
    60.     i2446
  4. 3Silicon Limitations
    1.     Revisions SR 1.0 - Limitations List
    2.     i596
    3.     i641
    4.     i833
    5.     i838
    6.     i845
    7.     i848
    8.     i876
    9.     i877
    10.     i892
    11.     i909
    12.     i925
  5. 4Silicon Cautions
    1.     Revisions SR 1.0 - Cautions List
    2.     i827
    3.     i832
    4.     i836
    5.     i839
    6.     i864
    7.     i885
    8.     i886
    9.     i912
    10.     i926
    11.     i931
    12.     i935
    13.     i937
  6. 5Revision History

i940

MPU COUNTER_REALTIME saturates after several hundred days

CRITICALITY

Major

DESCRIPTION

After several hundred days (specific duration depends on the primary input clock SYS_CLK1 frequency, see table below for example durations) of continuous operation the MPU COUNTER_REALTIME saturates at 0xBB8000000000 and no longer generates interrupts. There is no way to reset the counter except for a system reset.

For software/systems that use this timer and operate for extended periods of time without any type of reset or power cycle, this can lead to a system hang. For systems that regularly go through a power cycle or reset there is no issue.

SYS_CLK1 Days until saturation
19.2 MHz 404
20 MHz 388
27 MHz 287

WORKAROUND

Workaround 1: Avoid the issue by requiring the user to preform a scheduled reset/restart of the system sometime prior the saturation time.

Workaround 2: Recover from the issue by enabling a system watchdog reset to expire after the issue has occurred.

Workaround 3: Use GP Timer instead of COUNTER_REALTIME in systems requiring continuous up time.