Limitations; Mfx Mcu; Table 18. Mfx Signals - ST STM32L4R9I-EVAL User Manual

Hardware layout and configuration
Element
SB16
R30
SB17
SB18
6.26.1

Limitations

The touch-sensing button is exclusive with the DSI display connector, motor control, and
daughterboard connector.
6.27

MFX MCU

The MFX MCU is used as MFX (multi-function expander) and IDD measurement.
The MFX circuit on the STM32L4R9I-EVAL board acts as IO-expander. The communication
interface between MFX and STM32L4R9AII6 is the I2C2 bus. The signals connected to MFX
are listed in
Pin number
of MFX
15
16
17
42/72
Table 17. Touch-sensing-related configuration elements (continued)
Setting
Default setting.
Closed
PB6 is routed to the active shield under the touch sensing button. This
setting is not good for the robustness of touch sensing.
Default setting.
Open
PB6 is not routed to the CN16 DSI display connector.
PB6 is routed to the CN16 DSI display connector.
Closed
This setting is not good for the robustness of touch sensing.
PB7 port is routed to the CN5 connector of the daughterboard.
In
This setting is not good for the robustness of touch sensing.
Default setting.
Out
PB7 port is cut from CN5.
Default setting.
Open
PB7 is not routed to motor control.
PB7 is routed to motor control.
Closed
This setting is not good for the robustness of touch sensing.
PB7 is not routed to the sampling capacitor of the active shield under
the touch sensing button.
Open
This setting is not good for the robustness of touch sensing.
Default setting.
PB6 is routed to the sampling capacitor of the active shield under the
Closed
touch sensing button.
This setting is not good for the robustness of touch sensing.
Table 18.
Pin name
MFX functions
of MFX
PA5 MFX_GPIO5
PA6 MFX_GPIO6
PA7 MFX_GPIO7
Configuration

Table 18. MFX signals

Function of
STM32L4R9AII6
uS_Detect
USB _PSON
USB_OVRCR
UM2248 Rev 4
UM2248
Direction
Terminal
device
(for MFX)
Input microSD™
Output USB_FS
Input USB_FS