Datasheet
AM1808
SPRS653E –FEBRUARY 2010–REVISED MARCH 2014
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3.8 Unused Pin Configurations
All signals multiplexed with multiple functions may be used as an alternate function if a given peripheral is
not used. Unused non-multiplexed signals and some other specific signals should be handled as specified
in the tables below.
If NMI is unused, it should be pulled-high externally through a 10k-ohm resistor to supply DVDD3318_B.
Table 3-30. Unused USB0 and USB1 Signal Configurations
Configuration (When USB0 and USB1 are not
SIGNAL NAME Configuration (When only USB1 is not used)
used)
USB0_DM No Connect Use as USB0 function
USB0_DP No Connect Use as USB0 function
USB0_ID No Connect Use as USB0 function
USB0_VBUS No Connect Use as USB0 function
USB0_DRVVBUS No Connect Use as USB0 function
USB0_VDDA33 No Connect 3.3V
USB0_VDDA18 No Connect 1.8V
USB0_VDDA12 Internal USB PHY output connected to an external 0.22-μF filter capacitor
USB1_DM No Connect VSS or No Connect
USB1_DP No Connect VSS or No Connect
USB1_VDDA33 No Connect No Connect
USB1_VDDA18 No Connect No Connect
USB_REFCLKIN No Connect or other peripheral function Use for USB0 or other peripheral function
USB_CVDD 1.2V 1.2V
Table 3-31. Unused SATA Signal Configuration
SIGNAL NAME Configuration
SATA_RXP No Connect
SATA_RXN No Connect
SATA_TXP No Connect
SATA_TXN No Connect
SATA_REFCLKP No Connect
SATA_REFCLKN No Connect
SATA_MP_SWITCH May be used as GPIO or other peripheral function
SATA_CP_DET May be used as GPIO or other peripheral function
SATA_CP_POD May be used as GPIO or other peripheral function
SATA_LED May be used as GPIO or other peripheral function
SATA_REG No Connect
SATA_VDDR No Connect
Prior to silicon revision 2.0, this supply must be connected to a static 1.2V nominal supply.
SATA_VDD For silicon revision 2.0 and later, this supply may be left unconnected for additional power
conservation.
SATA_VSS VSS
Table 3-32. Unused RTC Signal Configuration
SIGNAL NAME Configuration
RTC_XI May be held high (CVDD) or low
RTC_XO No Connect
RTC_ALARM May be used as GPIO or other peripheral function
RTC_CVDD Connect to CVDD
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