Table 21-12. Connections for Unused Signals (100-Pin LQFP)
Preferred PracticeAcceptable PracticePin NumberSignal NameFunction
Connect to GND through 12.4-kΩ
resistor.
Connect to GND through
12.4-kΩ resistor.
33ERBIAS
Ethernet
GNDNC37RXIN
GNDNC40RXIP
GNDNC46TXON
GNDNC43TXOP
NCNC17XTALNPHY
a
GNDNC16XTALPPHY
a
GNDNC-All unused GPIOsGPIO
NCNC51HIB
Hibernate
GNDNC55VBAT
GNDNC50WAKE
GNDNC52XOSC0
NCNC53XOSC1
NCNC-NCNo Connects
GNDNC48OSC0
System
Control
NCNC49OSC1
Connect through a capacitor to
GND as close to pin as possible
Pull up as shown in Figure
5-1 on page 178
64RST
a. Note that the Ethernet PHY is powered up by default. The PHY cannot be powered down unless a clock source is provided
and the MDIO pin is pulled up through a 10-kΏ resistor.
Table 21-13 on page 978 shows how to handle signals for functions that are not used in a particular
system implementation for devices that are in a 108-ball BGA package. Two options are shown in
the table: an acceptable practice and a preferred practice for reduced power consumption and
improved EMC characteristics. If a module is not used in a system, and its inputs are grounded, it
is important that the clock to the module is never enabled by setting the corresponding bit in the
RCGCx register.
Table 21-13. Connections for Unused Signals (108-Ball BGA)
Preferred PracticeAcceptable PracticePin NumberSignal NameFunction
Connect to GND through
12.4-kΩ resistor.
Connect to GND through
12.4-kΩ resistor.
J3ERBIAS
Ethernet
GNDNCL7RXIN
GNDNCM7RXIP
GNDNCL8TXON
GNDNCM8TXOP
NCNCJ1XTALNPHY
a
GNDNCJ2XTALPPHY
a
GNDNC-All unused GPIOsGPIO
July 24, 2012978
Texas Instruments-Production Data
Signal Tables
OBSOLETE: TI has discontinued production of this device.