71
7679H–CAN–08/08
AT90CAN32/64/128
above mentioned sleep modes, as the clamping in these sleep modes produces the requested
logic change.
9.2.6
Unconnected Pins
If some pins are unused, it is recommended to ensure that these pins have a defined level. Even
though most of the digital inputs are disabled in the deep sleep modes as described above, float-
ing inputs should be avoided to reduce current consumption in all other modes where the digital
inputs are enabled (Reset, Active mode and Idle mode). The simplest method to ensure a
defined level of an unused pin, is to enable the internal pull-up. In this case, the pull-up will be
disabled during reset. If low power consumption during reset is important, it is recommended to
use an external pull-up or pull-down. Connecting unused pins directly to V
CC
or GND is not rec-
ommended, since this may cause excessive currents if the pin is accidentally configured as an
output.
9.3
Alternate Port Functions
Most port pins have alternate functions in addition to being general digital I/Os.
how the port pin control signals from the simplified
can be overridden by alternate
functions. The overriding signals may not be present in all port pins, but the figure serves as a
generic description applicable to all port pins in the AVR microcontroller family.
Содержание AVR AT90CAN128
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