Datasheet

11
ATtiny40 [SUMMARY DATASHEET]
8263BS–AVR–01/2013
8. Errata
The revision letters in this section refer to the revision of the corresponding ATtiny40 device.
8.1 Rev. B
• MISO output driver is not disabled by Slave Select (SS) signal.
• Current consumption in sleep modes may exceed specifications.
1. MISO output driver is not disabled by Slave Select (SS) signal.
When SPI is configured as a slave and the MISO pin is configured as an output the pin output driver is con-
stantly enabled, even when the SS
pin is high. If other slave devices are connected to the same MISO line this
behaviour may cause drive contention.
Problem Fix / Workaround
Monitor SS
pin by software and use the DDRC2 bit of DDRC to control the MISO pin driver.
2. Current consumption in sleep mode may exceed specifications
.
Some settings of register R27 may increase current consumption in sleep mode.
Problem Fix / Workaround
Before entering sleep mode, make sure register R27 is not loaded with 0x00 or 0x01.
8.2 Rev. A
Not sampled.