Limitations; Mfx Mcu; Table 19. Mfx Signals - ST STM32L4R9I User Manual

UM2248
Element
SB16
R30
SB17
SB18
6.26.1

Limitations

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

MFX MCU

The MFX MCU is used as MFX (multifunction expander) and IDD measurement.
The MFX circuit on the STM32L4R9I-EVAL main board acts as an 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
18
19
Table 18. Touch-sensing-related configuration elements (continued)
Setting
Default setting: PB6 is routed to the active shield under the touch-
ON sensing button. This setting is not good for the robustness of touch
sensing.
Default setting: PB6 is not routed to the DSI display connector
OFF
(CN16).
PB6 is routed to the DSI display connector (CN16).
ON
This setting is not good for the robustness of touch sensing.
PB7 port is routed to the CN5 connector of the daughterboard.
ON
This setting is not good for the robustness of touch sensing.
OFF Default setting: PB7 port is cut from CN5.
OFF Default setting: PB7 is not routed to motor control.
PB7 is routed to motor control.
ON
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.
OFF
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 touch-sensing button.
ON
This setting is not good for the robustness of touch sensing.
Table
Pin name
MFX functions
of MFX
PA5 MFX_GPIO5
PA6 MFX_GPIO6
PA7 MFX_GPIO7
PB0 MFX_GPIO0
PB1 MFX_GPIO1
Configuration
19.

Table 19. MFX signals

Function of
STM32L4R9AII6
uS_Detect
USB _PSON
USB_OVRCR
JOY_SEL
JOY_DOWN
UM2248 Rev 5
Hardware layout and configuration
Direction
(for MFX)
Input
Output
Input
Input
Input
Terminal
device
microSD™
USB_FS
USB_FS
Joystick
Joystick
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