Visible to Intel only — GUID: sfo1410068042802
Ixiasoft
Visible to Intel only — GUID: sfo1410068042802
Ixiasoft
7.1.3.8. Anti-Tamper
The Security Manager receives a tamper detection signal when a tamper event is detected in the device.
Anti-tamper logic can be implemented in the FPGA soft logic to detect a tamper event. No tamper detection is available until the FPGA is configured. The user must define the anti-tamper design. Some examples of tamper detection that could be implemented are:
- Using the FPGA voltage sensor to detect any IR drops across the device.
- Using an A/D controller to detect temperature changes in the device due to tamper.
- Assigning loaner I/O as dedicated tamper pins to detect package break-away.
The tamper detection signal sent to the Security Manager, anti_tamper_in, is an active low signal. When there is no tamper event, it is driven to 1. The Security Manager also provides a tamper acknowledge signal to the FPGA interface. The tamper event input to the HPS is gated with a signal indicating the completion of FPGA configuration. This prevents an inadvertent tamper event assertion or tamper response from the HPS to the rest of the system.
- Ethernet MAC 0/1/2
- USB OTG 0/1
- QSPI flash controller
- NAND flash controller
- SD/MMC controller
- DMA controller
Upon completion of memory scrambling of all IPs, the Security Manager sends a response to the FPGA indicating that a tamper event has been handled in the HPS. This response is followed by HPS entering into a cold reset without exiting until another power cycle occurs. Both Security Manager and Reset Manager enter reset. Other resets, such as warm reset or cold reset, do not affect the state of the Security Manager or the Reset Manager.
If the FPGA POR is de-asserted while the HPS is in a tamper event reset, then the Security Manager goes back to the reset state.