Overview
The TPM-Click board provides a TCG-standardised platform expanding trust from personal computing to connected devices. This board features the STMicroelectronics ST33KTPM2X, a STSAFE-TPM trusted platform module 2.0.
The STSAFE-TPM is a secure element product range providing authentication, confidentiality and platform integrity services to protect OEMs against cloning, counterfeiting, malware injection and unauthorised production. The STSAFE-TPM includes turnkey products compliant with the Trusted Computing Group (TCG) standards that provide services to protect the confidentiality, integrity and authenticity of information and devices. The STSAFE-TPM devices are all Common Criteria (EAL4+) and FIPS certified.
The ST33KTPM2X device is a member of the ST STSAFE-TPM (trusted platform module) family of products, which offers a broad portfolio of standardised solutions for embedded, PC, mobile and computing applications. The ST33KTPM2X is a TPM 2.0-compliant device, that is easy to integrate in an embedded design, using the standards-compliant SPI and I2C interfaces to the host SoC, such as the ST STM32MP1.
TPM-Click Module
The TPM-Click module is fully compatible with the Click / mikroBUS protocol. The only exception is use of the +5V power supply, which is not supported by the TPM-Click.
The default configuration of the TPM-Click module is to use the I2C Bus for communications with the host. The speed of the I2C Bus speed is limited 1MHz. If a higher throughput is required, then the SPI bus can be chosen. To select the SPI, the following parts must be populated: on the TPM-Click module:
R3-R6 soldered on
C1 soldered on
JP1 closed.
The following picture shows the TPM-Click module, in the default hardware configuration:
Hardware Specification
High-Level Specification
The following are the key characteristics of the TPM-Click module:
On-board Module | ST33KTPM2X, ST’ STSAFE-TPM trusted platform module 2.0 |
Host interface | I2C (default), SPI |
Compatibility | mikroBUS™ |
Click Board Size | S (28.6 x 25.4mm) |
Input Voltage | 3.3V |
Electrical Specification
The following is the electrical specification of the TPM-Click module:
Description | Min | Type | Max | Unit |
Supply Voltage | 3.0 | 3.3 | 3.6 | V |
I2C Interface Speed | 0 | - | 1000 | kHz |
SPI Interface Speed | - | - | 66 | MHz |
Operation Temperature Range | -40 | 25 | 105 | °C |
Current Consumption @ Run | - | 17.5 | - | mA |
Current Consumption @ Standby | - | 30 | - | µA |
Pin-out
The following table shows how the pin-out on the TPM-Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
Notes | Pin | Pin | Notes | ||||
| NC | 1 | AN | PWM | 16 | PP | Physical Presence, active high, internal pull-down. Used to indicate Physical Presence to the TPM. |
Reset | nRST | 2 | RST | INT | 15 | nIRQ | TPM interrupt request to the host, active low |
NC by default, optional SPI Chip (or Slave) Select | CS | 3 | CS | RX | 14 | NC |
|
NC by default, optional SPI Serial Clock | SCK | 4 | SCK | TX | 13 | NC |
|
NC by default, optional SPI Master Input, Slave Output | MISO | 5 | MISO | SCL | 12 | SCL | I2C Clock |
NC by default, optional SPI Master Output, Slave Input | MOSI | 6 | MOSI | SDA | 11 | SDA | I2C Data |
Power Supply | 3.3V | 7 | 3.3V | 5V | 10 | NC |
|
Ground | GND | 8 | GND | GND | 9 | GND | Ground |
On-board Jumpers
The following are the user-selectable on-board settings of the TPM-Click module:
Label | Name | State | Description |
SPI SEL | JP1 | Open (Default) | I2C interface is selected |
Closed | SPI is selected. R3-R6 and C1 must be installed to provide SPI connectivity. |
References
DB5174 STSAFE-TPM trusted platform module 2.0 with a SPI or I²C interface https://www.st.com/resource/en/data_brief/st33ktpm2x.pdf
https://www.st.com/en/secure-mcus/st33ktpm2x.html#documentation