Limitations; Operating Voltage; Touch-Sensing Button - STMicroelectronics STM32L476G-EVAL User Manual

Hardware layout and configuration
Table 26. Configuration elements related with Quad-SPI device (continued)
Element
SB21
SB20
MB979
SB9
MB979
SB8
MB979
2.25.1

Limitations

Quad-SPI operation is exclusive with LCD glass module and with motor control.
2.25.2

Operating voltage

Voltage of Quad-SPI Flash memory device N25Q256A13EF840E is in the range of 2.7 V to
3.6 V.
2.26

Touch-sensing button

The STM32L476G-EVAL evaluation board supports a touch sensing button based on either
RC charging or on charge-transfer technique. The latter is enabled, by default.
The touch sensing button is connected to PB12 port of STM32L476ZGT6 and the related
charge capacitor is connected to PB13.
An active shield is designed in the layer two of the main PCB, under the button footprint. It
allows reducing disturbances from other circuits to prevent from false touch detections.
The active shield is connected to PC6 port of STM32L476ZGT6 through the resistor
R37.The related charge capacitor is connected to PC7.
Table 27
them serve to enable or disable its operation. However, most of them serve to optimize the
touch sensing performance, by isolating copper tracks to avoid disturbances due to their
antenna effect.
46/100
Setting
Default setting.
SB21 open QSPI_D3 data line is not available at Quad-SPI Flash memory device:
SB20 open PA6 port of STM32L476ZGT6 is only routed to CN11 connector for the
MB979 daughterboard.
SB21 closed QSPI_D3 data line is available at Quad-SPI Flash memory device:
SB20 open PA6 port of STM32L476ZGT6 is routed to DQ3 port of Quad-SPI Flash
MB979 out memory device.
Default setting.
QSPI_CLK clock line is not available at Quad-SPI Flash memory device:
SB9 open
PB10 port of STM32L476ZGT6 is only routed to CN11 connector for the
MB979 daughterboard.
QSPI_CLK clock line is available at Quad-SPI Flash memory device:
SB9 closed
PB10 port of STM32L476ZGT6 is routed to C port of Quad-SPI Flash
MB979 out
memory device.
Default setting.
QSPI_CS line is not available at Quad-SPI Flash memory device:
SB8 open
PB11 port of STM32L476ZGT6 is only routed to CN11 connector for the
MB979 daughterboard.
QSPI_CS line is available at Quad-SPI Flash memory device:
SB8 closed
PB11 port of STM32L476ZGT6 is routed to S# port of Quad-SPI Flash
MB979 out
memory device.
shows the configuration elements related with the touch sensing function. Some of
DocID027351 Rev 3
Configuration
UM1855