Texas Instruments OMAP36 Series, Technical Reference Manual

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SCM Functional Description
Mode 0 is the primary mode. When mode 0 is set, the function mapped to the pin corresponds to the
name of the pin.
Mode 1 to Mode 7 are possible modes for alternate functions. On each pin, some modes are used
effectively for alternate functions, while other modes are unused and correspond to no functional
configuration.
The safe mode avoids any risk of electrical contention by configuring the pin as an input with no functional
interface mapped to it. The safe mode is used mainly as the default mode for all pins containing no
mandatory interface at the release of POR.
NOTE: Some pads do not have safe mode capability, and all eight mux modes are functional (for
instance: etk_d0). For such pads, safe mode can be emulated by configuring the pad in GPI
(muxmode 4).
For more information about the configurable mode on each pin, see Table 13-4 through Table 13-6 .
13.4.4.2 Pull Selection
Whichever pull value is configured, pulls are automatically disabled when a pin is configured as an output
(see
Table 13-3 ).
Table 13-3. Pull Selection
PULL Pin Behavior
PULLTYPESELECT PULLUDENABLE
0b0 0b0 Pulldown selected but not activated
0b0 0b1 Pulldown selected and activated if pin is NOT configured as
OUTPUT
0b1 0b0 Pullup selected but not activated
0b1 0b1 Pullup selected and activated if pin is NOT configured as
OUTPUT
For more information on the pull available on each pin, see Table 13-4 through Table 13-6 .
13.4.4.3 Pad Multiplexing Register Fields
Table 13-4 through Table 13-6 provide for each pad configuration register field the address offset , reset
values, and associated signal name for each multiplexing mode (as set by the MUXMODE bit field ). Mode
0 is always defined. Modes with no signal name are undefined for the given pad.
NOTE:
• Pad configuration registers are split into three types, which correspond to the following
three tables:
– Table 13-4 lists the pad configuration registers instantiated in the CORE power
domain that drive the pads in the CORE power domain.
– Table 13-5 lists the pad configuration registers instantiated in the CORE power
domain that drive the D2D pads. These pads are available in stacked mode only.
– Table 13-6 lists the pad configuration registers instantiated in the WKUP power
domain that drive the pads in the WKUP power domain.
• In Table 13-4 through Table 13-6 , an empty cell indicates that the mode or pull is not
available for this pin.
2447 SWPU177N – December 2009 – Revised November 2010 System Control Module
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