Functional Description
9.2.2.1
Mode Selection
The MUXMODE field in the pad control registers defines the multiplexing mode applied to the pad. Modes
are referred to by their decimal (from 0 to 7) or binary (from 0b000 to 0b111) representation. For most
pads, the reset value for the MUXMODE field in the registers is 0b111. The exceptions are pads to be
used at boot time to transfer data from selected peripherals to the external flash memory.
Table 9-2. Mode Selection
MUXMODE
Selected Mode
000b
Primary Mode = Mode 0
001b
Mode 1
010b
Mode 2
011b
Mode 3
100b
Mode 4
101b
Mode 5
110b
Mode 6
111b
Mode 7
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.
9.2.2.2
Pull Selection
There is no automatic gating control to ensure that internal weak pull- down/pull up resistors on a pad are
disconnected whenever the pad is configured as output. If a pad is always configured in output mode, it is
recommended for user software to disable any internal pull resistor tied to it, to avoid unnecessary
consumption. The following table summarizes the various possible combinations of PULLTYPESEL and
PULLUDEN fields of PAD control register.
Table 9-3. Pull Selection
PULL TYPE
Pin Behavior
PULLTYPESEL
PULLUDENABLE
0b
0b
Pulldown selected and activated
0b
1b
Pulldown selected but not activated
1b
0b
Pullup selected and activated
1b
1b
Pullup selected but not activated
9.2.2.3
RX Active
The RXACTIVE bit is used to enable and disable the input buffer. This control can be used to help with
power leakage or device isolation through the I/O. The characteristic of the signal is ultimately dictated by
the mux mode the pad is put into.
9.2.3 EDMA Event Multiplexing
The device has more DMA events than can be accommodated by the TPCC’s maximum number of
events, which is 64. To overcome the device has one crossbar at the top level. This module will multiplex
the extra events with all of the direct mapped events. Mux control registers are defined in the Control
Module to select the event to be routed to the TPCC. Direct mapped event is the default (mux selection
set to ‘0’).
748
Control Module
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated