dedicated SPI4CLK pad
multiplexed SPI4CLK pad
to other input functions
multiplexed with SPI4CLK
SPI4CLK_IN
SPI4
Combination of PINMMR5[1]
and PINMMR23[8]
Control of Multiplexed Functions
231
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
I/O Multiplexing and Control Module (IOMM)
Figure 4-3. Input Multiplexing Example
4.3.3 Control of Special Multiplexed Options
PINMMR29 and PINMMR30 registers are used to control some specific device functions.
•
EMIF_CLK Control:
PINMMR29[8] is set by default. This is used to block the EMIF_CLK from being output from the
microcontroller. If the EMIF is used to connect to an external SDRAM module, then the application must
enable the EMIF_CLK output by clearing the PINMMR29[8] bit.
•
Control for other EMIF Signals:
Bit 31 of the system module control register GPREG1 at address 0xFFFFFFA0 is used to gate off the
EMIF module outputs: EMIF_ADDR[0], EMIF_ADDR[1], EMIF_ADDR[6], EMIF_ADDR[7], EMIF_ADDR[8],
EMIF_BA[1], EMIF_nCS[0], EMIF_nCS[3]. These 8 signals are multiplexed with NHET2 signals. By
default, these terminals are tri-stated and pulled down. Any application that requires the EMIF functionality
must set GPREG1[31]. This allows these 8 EMIF module outputs to be driven on to the assigned balls.
•
Ethernet Controller Mode Control:
PINMMR29[24] is set by default. This bit is used to enable the Reduced Media Independent Interface of
the Ethernet controller. If the application desires to use the Media Independent Interface of the Ethernet
controller, then the PINMMR29[24] must be cleared.
•
ADC Trigger Control:
The microcontrollers contain two Analog-to-Digital Converter (ADC) modules. The ADC conversions can
be started using a rising or falling or both edges as the trigger event. Both the ADC modules support up to
eight event trigger inputs. There are two sets of these 8 inputs for each ADC. The first set is the default
set and is selected by setting the PINMMR30[0]. The PINMMR30[0] is also set by default. The alternate
set of 8 event trigger options are selected by clearing PINMMR30[0] bit.
•
Generating Interrupt when fault is indicated to N2HET2
The N2HET modules on this microcontroller support a mechanism to respond to faults indicated on their
PIN_nDIS inputs. This input for the N2HET2 module is connected to the MibSPI3_nCS[0]/AD2EVT
terminal. When this terminal is driven low, the N2HET2 can be configured to tri-state all PWMs output from
the N2HET2. It is very useful to be able to generate an interrupt to the host CPU when this happens.
Therefore, the MibSPI3_nCS[0] / AD2EVT signal is also available to be connected to the GIOB[2] signal.
This device also contains a dedicated terminal for the GIOB[2] signal. This necessitates a multiplexor on
the input connection to the GIOB[2]. This multiplexor's selection is controlled by PINMMR29[16]. When
PINMMR29[16] is cleared (0, default), the connection to the GIOB[2] comes from the dedicated terminal.
When PINMMR29[16] is set, the connection to the GIOB[2] comes from the MibSPI3_nCS[0] / AD2EVT
terminal. Enabling this connection to the GIOB[2] allows the application to generate a GIO interrupt to the
host CPU when the external fault monitor circuitry drives the MibSPI3_nCS[0] / AD2EVT terminal low to
indicate a fault condition to the N2HET2 module.