ST X-NUCLEO-SAFEA1B Operating instructions

Introduction
The X-NUCLEO-SAFEA1B expansion board is based on the STSAFE-A110 secure element. It can be used with any STM32
Nucleo development board.
The on-board STSAFE-A110 is customized with a standard profile for evaluation and is compatible with the Arduino UNO R3
connector.
The X-NUCLEO-SAFEA1B expansion board is used with free X-CUBE-SAFEA1 or X-CUBE-SBSFU software packages
containing sample code to demonstrate how to implement security applications.
Figure 1. X-NUCLEO-SAFEA1B
How to use STM32 Nucleo expansion board based on the STSAFE-A110 secure
element
UM3195
User manual
UM3195 - Rev 1 - June 2023
For further information contact your local STMicroelectronics sales office. www.st.com

1 Getting started
1.1 Hardware requirements
The X-NUCLEO-SAFEA1B expansion board can be connected to any STM32 Nucleo development board through
the matching Arduino UNO R3 connector pins.
Note: Handle the X-NUCLEO-SAFEA1B with care and avoid bending or damaging the pins as the board has male/
female pass-through connectors and ESD sensitive components.
1.2 System requirements
To complete the system setup, you need:
• a PC running Windows version 7, 8 or 10
• a USB type A to mini-B USB cable to connect the STM32 Nucleo to the PC
• software package (X-CUBE-SAFEA1 or X-CUBE-SBSFU) installed on the user PC
• one of the compatible software development environments: IAR, Arm Keil, AC6, or Atolic
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Getting started
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2 Hardware description
The X-NUCLEO-SAFEA1B expansion board has an embedded STSAFE-A110 secure element to allow you to
evaluate its authentication and data management services connected to a local or remote host.
This STSAFE-A110 is factory personalized with a generic sample profile.
The main features of the X-NUCLEO-SAFEA1B expansion board are:
• On-board STSAFE-A110 customized with a standard evaluation profile
• HE10 extension connector to mount additional STSAFE devices
• Arduino UNO R3 connector
• Free drivers, middleware and software samples compatible with the STM32 ODE
• RoHS and WEEE compliant
The X-NUCLEO-SAFEA1B interfaces with the STM32 Nucleo microcontrollers via the I²C communication bus.
2.1 Jumpers and solder bridges
Table 1. X-NUCLEO-SAFEA1B expansion board jumper and solder bridge functions
Jumper Alternative soldering point function
P1 SB13 Connects embedded LD3 green LED to STM32 Nucleo board
P4 SB1 Connects embedded 2.2kΩ pull-ups to I²C bus for SCL
P5 SB2 Connects embedded 2.2kΩ pull-ups to I²C bus for SDA
P7 Can be used to put STSAFE-A110 secure element in reset mode
SB5 Can be used to drive the STSAFE-A110 reset pin via the STM32 MCU PC0 GPIO
2.2 Connector
X-NUCLEO-SAFEA1B Nucleo expansion board has an HE10 extension connector (J2) to mount an additional
STSAFE-A1xx secure element.
Note: If you use the connector to accommodate new generation STSAFE-A devices, be sure that you insert jumper P7
to place the current STSAFE-A110 secure element soldered on the board in reset mode.
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Hardware description
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3 STM32L4 series microcontroller software
The STM32 ODE software package X-CUBE-SAFEA1 provides demonstration source code for a NUCLEO-
L476RG development board with X-NUCLEO-SAFEA1B expansion. The X-CUBE-SAFEA1 package includes
drivers, middleware and several demonstration codes that implement the features of the STSAFE-A110 device
through a host microcontroller. The demonstration codes use the STSAFE-A1xx middleware built on the
STM32Cube software technology. They illustrate authentication, key pair generation, key establishment, local
envelope wrapping and pairing features.
Another package, called X-CUBE-SBSFU, provides demonstration source code for Secure Boot and Secure
Firmware Update solution. It updates of the STM32 microcontroller firmware with new features and addresses
potential issues. The update process is a secure operation using the STSAFE-A110 to prevent unauthorized
updates and access to confidential on-device data. It is available for the STM32L4 Series microcontrollers with
examples provided for the B-L475E-IOT01A discovery kit with the X-NUCLEO-SAFEA1B expansion.
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STM32L4 series microcontroller software
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4 Schematic diagrams
Figure 2. X-NUCLEO-SAFEA1 circuit schematic - STSAFE-A chips
4GND
SCL 7
IC4
GND
4
3NC
3V3
NC 6
3V3
1RST
NC
3
C3
VCC
2
RESET-C2
3V3
100nF/25V
100nF/25V
NC
1
STSAFE-A110 UFDFPN8 3x2
C2
IC1
SDA 5
GND
SDA 5
SCL
IC2
GND
4
STSAFE-A110 SO8N
2VCC
3NC
2VCC
SDA
RESET-C1
SDA
STSAFE-A110 UFDFPN8 3x2
SCL
RESET-C1
GND
RST
1
NC 6
RST 8
SCL
7
SCL 2VCC
7
SCL
NC 8
SCL
RESET-C2
SDA
RST 8
IC3
1NC
NC
3
NC 6
GND
SDA
STSAFE-A110 SO8N
SCL 7
NC 8
3V3
4GND
GND
NC 6
SDA 5
SDA 5
UM3195 - Rev 1 page 5/16
UM3195
Schematic diagrams

Figure 3. X-NUCLEO-SAFEA1 circuit schematic - Arduino and morpho connectors
morpho connector
8
32
18
13
CN10
CN9
10
28
9
4
PA9
7
2
3
16
GND
33
34
21 22
14
CN6
3V3
2
3
4
5
5
Arduino connector
2
17
12
Header 19x2
9
3 5
GND
1
21 22
25
SPI_CLK
27
34
11
1
1
8
29 30
4
23 24
1
4
13
12
35 36
11
20
31
PC0
PC1
2
1
CN5
SPI_MOSI
SPI_MISO
SPI_NSS 16 6
7
8
Header 19x2
26
6
CN8
8
7
6
10
15
19
7
9
5
28
29
38
37
CN7
25
PA10
7
2
19
E5V
30
10
5
1
3
3
14
15
5V
PA11
PA12
PH1
PH0
morpho connector
2
27
SDA
SCL
31
5
8
26
4
3
6
20
6
4
CN5-6
32
33
6
35 36
1817
23 24
38
37
Arduino connector
Arduino connector Arduino connector
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UM3195
Schematic diagrams

Figure 4. X-NUCLEO-SAFEA1 circuit schematic - LEDs and jumpers
1K
R8
2K2
1%
2
P4
2
R5
1KR
PC0
(CN8-Pin 6)
LD3
SDA
3V3
1%
RST1
SDA
SCL pull-up
SCL
61.9R
1
Amber LED
P7
RESET-C1
1%
1
1%
2
P5
SDA pull-up
GND
8
GND
3V3
1
9
4
R3
CN5-6
3V33V3
R7
R1
SPI_MOSI
2
P1
SB5
Sel SCL Sel SDA
pull-up
RST1 CMD
pull-up
SPI_MISO
SPI_CLK
SPI_NSS
2
820R
1
3
3V3
1%
User Led
Header 5X2 male
6
GND
10
J2
SCL
7
(CN5-Pin 9)
SB13
1%
LD1
2K2
5
1
R4
(CN5-Pin 10)
Green LED
SB2
SB1
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Schematic diagrams

5 Bill of materials
Table 2. X-NUCLEO-SAFEA1B bill of materials
Item Q.ty Reference Part/Value Description Manufacturer Order code
1 1 C2
0.1 µF 0603 [1608
Metric] 25 V ± 10 %
SMD X7R
Multilayer ceramic
capacitor Multicomp MC0603B104K250CT
2 0 C3 0.1 µF 0603 [1608
Metric] 25 V ± 10 %
Multilayer ceramic
capacitor (not
mounted)
Multicomp MC0603B104K250CT
3 0 C4, C5
22 pF 0603 [1608
Metric] 50 V ± 5%
C0G/NP0
Multilayer ceramic
capacitors (not
mounted)
Multicomp MC0603N220J500CT
4 1 CN5
Vertical, 2.54 mm, 10
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector SAMTEC ESQ-110-24-T-S
5 1 CN6
Vertical, 2.54 mm, 8
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector SAMTEC ESQ-108-24-T-S
6 0 CN7
Vertical, 2.54 mm, 38
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector (not
mounted)
SAMTEC ESQ-119-14-G-D
7 1 CN8
Vertical, 2.54 mm, 6
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector SAMTEC ESQ-106-24-T-S
8 1 CN9
Vertical, 2.54 mm, 8
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector SAMTEC ESQ-108-24-T-S
9 0 CN10
Vertical, 2.54 mm, 38
contacts, receptacle,
ESQ series, through
hole
Board-to-board
connector (not
mounted)
SAMTEC ESQ-119-14-G-D
10 1 IC1 STSAFE-A110 SO8N
Authentication and
brand protection
secure solution
ST STSAFA110DFSPL03
11 0 IC2 STSAFE-A110 SO8N
Authentication and
brand protection
secure solution (not
mounted)
ST STSAFA110DFSPL03
12 0 IC3, IC4 STSAFE-A110 DFN23
Authentication and
brand protection
secure solution (not
mounted)
ST STSAFA110DFSPL03
13 1 LD1 SM0805AC, 6MCD,
607 Amber LED Bivar Inc. SM0805AC
14 0 LD2 SM0805AC, 6MCD,
607
Amber LED (not
mounted) Bivar Inc. SM0805AC
15 1 LD3 1.8 V 2 mA 570 nm Green LED OSRAM LGT67K-H2K1-24-Z
16 0 J1
Receptacle, 5 ways,
surface mount, right
angle
USB connector,
shielded, Micro
USB Type B, USB
2.0 (not mounted)
MOLEX 47346-0001
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Bill of materials
UM3195 - Rev 1 page 8/16

Item Q.ty Reference Part/Value Description Manufacturer Order code
17 1 J2
2.54 mm, 10 contacts,
header, 303 Series,
through hole, 2 rows
Wire-to-board
connector 3M 30310-6002HB
18 1 P7, P8 473, 80 way, 2 row,
straight pin header Connector Stelvio Kontek 613080262822
19 1 R1 61.9 ohm 0603 [1608
Metric] 75 V 100 mW Thick film resistor MULTICOMP MCWR06X61R9FTL
20 0 R2 680 ohm 0603 [1608
Metric] 50 V 100 mW
Thick film resistor
(not mounted) MULTICOMP MCWR06X6800FTL
21 4 R3, R4, R7,
R8
2.2 kohm 0603 [1608
Metric] 50 V 100 mW
SMD
Chip resistors MULTICOMP MCWR06X2201FTL
22 1 R5 1 kohms 0603 [1608
Metric] ±1% Resistor MULTICOMP MCMR06X1001FTL
23 0 R6 1 kohms 0603 [1608
Metric] ±1%
Resistor (not
mounted) MULTICOMP MCMR06X1001FTL
24 3 SB1, SB2,
SB13
0 ohm 0603 [1608
Metric] 75 V 100 mW Chip resistor Vishay CRCW06030000Z0EA
25 0 SB3, SB10,
SB11, SB12
0 ohm 0603 [1608
Metric] 75 V 100 mW
Chip resistor (not
mounted) Vishay CRCW06030000Z0EA
26 0 X1
8 MHz, through hole,
11.5 mm x 5 mm, 10
ppm, 18 pF, 10 ppm,
9B Series
9B-8.000MEEJ-B -
Crystal, TXC Corp. 9B-8.000MEEJ-B
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Bill of materials
UM3195 - Rev 1 page 9/16

6 Board versions
Table 3. X-NUCLEO-SAFEA1 versions
CPN Finished good Schematic diagrams Bill of materials
X-NUCLEO-SAFEA1B X$NUCLEO-SAFEA1B (1) X$NUCLEO-SAFEA1B
schematic diagrams
X$NUCLEO-SAFEA1B bill of
materials
1. This code identifies the X-NUCLEO-SAFEA1B evaluation board first version.
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Board versions
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