AT32UC3L0-XPLD Atmel, AT32UC3L0-XPLD Datasheet - Page 85

• Manufacturer Part Number: AT32UC3L0-XPLD
• Description: KIT DEV/EVAL FOR AT32UC3L0
• Manufacturer: Atmel

Specifications of AT32UC3L0-XPLD

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.2.4
10.2.5
32099F–11/2010
SCIF
AST
4. Instability when exiting sleep walking
5. Clock Failure Detector (CFD) can be issued while turning off the CFD
6. Sleepwalking in Idle and Frozen Sleep mode will mask all other PB clocks
1. PCLKSR.OSC32RDY bit might not be cleared after disabling OSC32K
1. Reset may set status bits in the AST
2. AST wake signal is released one AST clock cycle after the BUSY bit is cleared
- When entering Shutdown mode while debugging the chip using JTAG or aWire interface.
In the listed cases, writing a one to the bit VREGCR.POR33MASK in the System Control
Interface (SCIF) to mask the POR33 reset will be ineffective.
Fix/Workaround
- Do not disable POR33 using the user interface.
- Do not use the SM33 supply monitor.
- Do not enter Shutdown mode if a debugger is connected to the chip.
If all the following operating conditions are true, exiting sleep walking might lead to
instability:
-The OSC0 is enabled in external clock mode (OSCCTRL0.OSCEN == 1 and
OSCCTRL0.MODE == 0)
-A sleep mode where the OSC0 is automatically disabled is entered
-The chip enters sleep walking
Fix/Workaround
Do not run OSC0 in external clock mode if sleep walking is expected to be used.
While turning off the CFD, the CFD bit in the Status Register (SR) can be set. This will
change the main clock source to RCSYS.
Fix/Workaround
Solution 1: Enable CFD interrupt. If CFD interrupt is issues after turning off the CFD, switch
back to original main clock source.
Solution 2: Only turn off the CFD while running the main clock on RCSYS.
If the CPU is in Idle or Frozen Sleep mode and a module is in a state that triggers sleep
walking, all PB clocks will be masked except the PB clock to the sleepwalking module.
Fix/Workaround
Mask all clock requests in the PM.PPCR register before going into Idle or frozen mode.
In some cases the OSC32RDY bit in the PCLKSR register will not be cleared when OSC32K
is disabled.
Fix/Workaround
When re-enabling the OSC32K, read the PCLKSR.OSC32RDY bit. If this bit is:
0: Follow normal procedures.
1: Ignore the PCLKSR.OSC32RDY and ISR.OSC32RDY bit. Use the Frequency Meter
(FREQM) to determine if the OSC32K clock is ready. The OSC32K clock is ready when the
FREQM measures a non-zero frequency.
If a reset occurs and the AST is enabled, the SR.ALARM0, SR.PER0, and SR.OVF bits may
be set.
Fix/Workaround
If the part is reset and the AST is used, clear all bits in the Status Register (SR) before enter-
ing sleep mode.
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