Datasheet

419
7766F–AVR–11/10
ATmega16/32U4
35. Errata
The revision letter in this section refers to the revision of the ATmega16U4/ATmega32U4
device.
35.1 ATmega16U4/ATmega32U4 Rev E
• Spike on TWI pins when TWI is enabled
• High current consumption in sleep mode
• MSB of OCR4A/B/D is write only in 11-bits enhanced PWM mode
1. Spike on TWI pins when TWI is enabled
100 ns negative spike occurs on SDA and SCL pins when TWI is enabled.
Problem Fix/work around
Enable ATmega16U4/ATmega32U4 TWI before the other nodes of the TWI network.
2. High current consumption in sleep mode
If a pending interrupt cannot wake the part up from the selected mode, the current consump-
tion will increase during sleep when executing the SLEEP instruction directly after a SEI
instruction.
Problem Fix/work around
Before entering sleep, interrupts not used to wake up the part from the sleep mode should
be disabled.
3. MSB of OCR4A/B/D is write only in 11-bits enhanced PWM mode
In the 11-bits enhanced PWM mode the MSB of OCR4A/B/D is write only. A read of
OCR4A/B/D will always return zero in the MSB position.
Problem Fix/work around
None.
35.2 ATmega16U4/ATmega32U4 Rev D
• Spike on TWI pins when TWI is enabled
• High current consumption in sleep mode
• Timer 4 11-bits enhanced PWM mode
1. Spike on TWI pins when TWI is enabled
100 ns negative spike occurs on SDA and SCL pins when TWI is enabled.
Problem Fix/work around
Enable ATmega16U4/ATmega32U4 TWI before the other nodes of the TWI network.
2. High current consumption in sleep mode
If a pending interrupt cannot wake the part up from the selected mode, the current consump-
tion will increase during sleep when executing the SLEEP instruction directly after a SEI
instruction.
Problem Fix/work around
Before entering sleep, interrupts not used to wake up the part from the sleep mode should
be disabled.