Datasheet

107
[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET]
8067O–AVR–06/2013
36.2 ATxmega64A1 and ATxmega128A1 rev. G
 Bootloader Section in Flash is non-functional
 Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously
 DAC is nonlinear and inaccurate when reference is above 2.4V
 ADC gain stage output range is limited to 2.4 V
 The ADC has up to ±2 LSB inaccuracy
 TWI, a general address call will match independent of the R/W-bit value
 TWI, the minimum I
2
C SCL low time could be violated in Master Read mode
 Setting HIRES PR bit makes PWM output unavailable
 EEPROM erase and write does not work with all System Clock sources
 BOD will be enabled after any reset
 Propagation delay analog Comparator increasing to 2 ms at -40C
 Sampled BOD in Active mode will cause noise when bandgap is used as reference
 Default setting for SDRAM refresh period too low
 Flash Power Reduction Mode can not be enabled when entering sleep mode
 Enabling Analog Comparator B output will cause JTAG failure
 JTAG enable does not override Analog Comparator B output
 Bandgap measurement with the ADC is non-functional when V
CC
is below 2.7V
 DAC refresh may be blocked in S/H mode
 Inverted I/O enable does not affect Analog Comparator Output
 Both DFLLs and both oscillators has to be enabled for one to work
1. Bootloader Section in Flash is non-functional
The Bootloader Section is non-functional, and bootloader or application code cannot reside in this part of the
Flash.
Problem fix/Workaround
None, do not use the Bootloader Section.
2. Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously
If the Bandgap voltage is selected as input for one Analog Comparator (AC) and then selected/deselected as input
for the another AC, the first comparator will be affected for up to 1 us and could potentially give a wrong compari-
son result.
Problem fix/Workaround
If the Bandgap is required for both ACs simultaneously, configure the input selection for both ACs before enabling
any of them.
3. DAC is nonlinear and inaccurate when reference is above 2.4V
Using the DAC with a reference voltage above 2.4V give inaccurate output when converting codes that give below
0.75V output:
 ±20 LSB for continuous mode