Arduino A000053 Fiche technique télécharger pdf (Page 20)

7766FS–AVR–11/10

ATmega16/32U4

8. Errata

The revision letter in this section refers to the revision of the ATmega16U4/ATmega32U4

device.

8.1 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.

8.2 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.

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Arduino A000053 Fiche technique Page 20