Two workarounds are available.
- Use the DMA trigger to determine when the TIMESTAMP value is
registered. The DMA trigger sets after the TIMESTAMP register update.
- Implement a wait loop to create a delay when the tamper interrupt handler
routine begins to when the TIMESTAMP register is read. The delay must be
long enough to wait for 3x CLK_RTC period. Example:
* If CLK_RTC frequency is 1KHz, the delay must be at least 3ms.
* If CLK_RTC frequency is 32KHz, the delay must be at least 92us.
6 – If PB01 is multiplexed to RTC peripheral (RTC/IN2), the system will
always see this input pin as logic ‘0’ when backup mode is entered. If
the detection transition (TAMPCTRL.TAMLVL2 = 0), it might falsely
wake up the system.
Errata reference: 15010
Fix/Workaround:
If the system is expected to enter backup mode, use other tamper pins
(IN0/IN1/IN3/IN4) for tamper detection.
49.1.5. TRNG
1 – When TRNG is enabled with configuration CTRL.RUNSTDBY = 0,
(disabled during sleep) it could still continue to operate resulting in
over-consumption (~50uA) in standby mode.
Errata reference: 14827
Fix/Workaround:
Disable the TRNG before entering standby mode.
49.1.6. Device
1 – Writing PM.STDBYCFG.VREGSMOD to one does not set the main
voltage regulator in standby mode, the low power regulator is still used
in standby mode.
Errata reference: 14543
Fix/Workaround :
Set SUPC.VREG.RUNSTDBY to one.
2 – Five PTC lines are mapped on PC00, PC01, PB00, PB01, PB02
instead of PC05, PC06, PA11, PA10, PA09
Errata reference: 14792
Fix/Workaround:
None.
3 – When LCD feature is enable and (VLCD - VDD) > 0.7V, an extra
consumption occurs. In case of VLCD internally generated, the VLCD
voltage will be out of specification.
Errata reference: 14696
Fix/Workaround :
LCD feature must be used only when (VLCD - VDD) < 0.7V
4 – When ABS(VLCD - VDD) < 50mV, an extra consumption can occur
on VLCD (if VLCD generated externally) or on VDD (if VLCD generated
internally).
Errata reference: 14742
Fix/Workaround :
ABS(VLCD - VDD) should be greater than 50mV
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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