Datasheet

311
7734Q–AVR–02/12
AT90PWM81/161
4. Flash and EEPROM programming failure if CPU clock is switched
If Clock switching is used in the Application, the memory programming is only possible when
the internal RC oscillator is selected as System clock.
If the Application requires a memory programming on a clock source different from the inter-
nal RC oscillator, do not switch to this clock source.
Work around:
- Use internal RC oscillator when programming Flash and EEPROM,
or
- Do not use clock switching
5. ADC AMPlifier measurement is unstable
When switching from a single-ended ADC channel to an Amplified channel, noise can
appear on ADC conversion.
Work around:
After switching from a single ended to an amplified channel, discard the first ADC
conversion.
6. ADC measurement reports abnormal values with PSC2-synchronized
conversions
When using ADC in synchronized mode, an unexpected extra Single ended conversion can
spuriously re-start.This can occur when the End of conversion and the Trigger event occur
at the same time.
Work around:
No workaround
7. Over-consumption in power down sleep mode
In Power-down mode, an extra power consumption up to 500µA may occur.
Work around:
No workaround
27.5 Errata AT90PWM81 revE
• Clock Switch disable
• Crystal oscillator control with Clock Switch
• BOD disable fuse
1. Clock Switch enable & disable
After a “Enable Clock Source” or a “Disable Clock Source” command, the command is still
active until the next access of CLKCSR register. If CLKSEL is written with a new value, the
corresponding clock will be unintentionnaly enabled or disabled.
Work around:
Atter the Enable or Disable command, write CLKCSR with value 1<<CLKCCE