S/AI
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4.3 Handling of Unused Signals
Depending on the application, not all signals of S may be needed. The following list
gives some hints how to handle unused signals.
•
EXT-RES#
If no external Reset is needed: Leave open
•
BOOT0
leave open
(1)
•
XL-IN/SLCK
If no external slow clock is provided: Leave open
•
XL-OUT
If no external XTAL is connected: Leave open
•
UART-RTS#, UART-CTS# If neither flow control nor UICP is used: Leave open
(1)
•
IUR-OUT#, IUR-IN#
If UICP is not used: leave open
•
TESTMODE#
Leave open
(1)
•
unused GPIOs
Leave open
•
SWDIO, SWCLK
Leave open. Only needed for debug purposes.
Please note, to keep compatibility with future feature enhancements, unused signals shall not be
connected directly to VSUP or GND. Leave open.
(1)
Signals must be accessible during the homologation process, refer to 3.10 Test Mode Enable.
