ST STM32L053 - Figure 4. Bottom Layout

Hardware layout UM1775
12/39 UM1775 Rev 4
Figure 4. Bottom layout
MSv34156V3
Reserved
(SB4, 5, 6, 11)
Default
(SB7,8,9,12)
STM_RST
(SB10)
RX, TX
(SB14,15)
X2 crystal
(SB18,19)
Crystal
(X2)
MCO
(SB20)
OSC_IN
(SB21)
Touch sensor
(SB23, 24, 25, 26, 27, 28)
B2 – RESET
(SB29)
STM32L053C8T6
(U8)
B1 – USER
(SB22)
USB_USER
(SB16, 17)
NRST
(SB13)