Datasheet

[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET]

8067O–AVR–06/2013

12. Sampled BOD in Active mode will cause noise when bandgap is used as reference

Using the BOD in sampled mode when the device is running in Active or Idle mode will add noise on the bandgap

reference for ADC and DAC.

Problem fix/Workaround

If the bandgap is used as reference for either the ADC or the DAC, the BOD must not be set in sampled mode.

13. Default setting for SDRAM refresh period too low

If the SDRAM refresh period is set to a value less then 0x20, the SDRAM content may be corrupted when access-

ing through On-Chip Debug sessions.

Problem fix/Workaround

The SDRAM refresh period (REFRESHH/L) should not be set to a value less then 0x20.

14. Flash Power Reduction Mode can not be enabled when entering sleep mode

If Flash Power Reduction Mode is enabled when entering Power-save or Extended Standby sleep mode, the

device will only wake up on every fourth wake-up request.

If Flash Power Reduction Mode is enabled when entering Idle sleep mode, the wake-up time will vary with up to 16

CPU clock cycles.

Problem fix/Workaround

Disable Flash Power Reduction mode before entering sleep mode.

15. JTAG enable does not override Analog Comparator B output

When JTAG is enabled this will not override the Anlog Comparator B (ACB)ouput, AC0OUT on pin 7 if this is

enabled.

Problem fix/Workaround

AC0OUT for ACB should not be enabled when JTAG is used. Use only analog comparator output for ACA when

JTAG is used, or use the PDI as debug interface.

16. Bandgap measurement with the ADC is non-functional when V

is below 2.7V

The ADC cannot be used to do bandgap measurements when V

is below 2.7V.

Problem fix/Workaround

If internal voltages must be measured when V

is below 2.7V, measure the internal 1.00V reference instead of

the bandgap.