Datasheet

 2018 Microchip Technology Inc. Data Sheet Complete DS40002058A-page 215
ATxmega128A1U/ATxmega64A1U
Align the endpoint configuration table pointer in SRAM to a 16-byte. This workaround is implemented in all USB soft-
ware and source code delivered from Microchip in the AVR Software Framework.
10. USB Auto ZLP feature is non-functional
The Auto ZLP feature is non-functional and can not be used.
Problem fix/Workaround
None.
11. Disabling the USART transmitter does not automatically set the TxD pin direction to input
If the USART transmitter is idle with no frames to transmit, setting TXEN to zero will not automatically set the TxD pin
direction to input.
Problem fix/Workaround
The TxD pin direction can be set to input using the Port pin direction to input using the port direction (DIR) register.
When the port pin direction is input, it will be immediate and ongoing transmissions will be truncated.
12. TWI, SDAHOLD configuration in the TWI CTRL register is one bit
The SDAHOLD configuration in the TWI Control register (CTRL) is one bit. Due to this the SDA hold time can be con-
figured for maximum ~50ns when enabled. Configuring for longer hold time will have no effect.
Problem fix/Workaround
If longer SDA hold time than 50nS is required it must be handled in software.
13. ADC has increased INL error in when used in SE unsigned mode at low temperatures
When the ADC is used on single ended (SE) unsigned mode, -INL error is increased up to +/- 5 LSB in temperatures
below -20C.
Problem fix/Workaround
Use the ADC in single ended signed mode.
14. ADC is non-functional in SE unsigned mode with V
REF
below 1.8V
When the ADC is used on single ended unsigned mode and V
REF
is below 1.8V, INL and DNL error is increased above
+/- 10LSB, i.e. the ADC have missing codes under this condition.
Problem fix/Workaround
Use the ADC in single ended signed mode.
15. ADC has increased linearity error when using the gain stage above 500ksps
The INL error for gain stage is increased to above 20LSB for sampling speed exceeding 500 ksps.
Problem fix/Workaround
None.
16. DAC Offset calibration range too small when using AVCC as reference
If using AVCC as reference, the DAC offset calibration will not totally remove the offset error. Offset could be up to
100LSB after calibration.
Problem fix/Workaround
Offset adjustment must be partly handled in software.