3.7.5.1 Bus Interfaces

The OTPC features four bus interfaces to access the OTP memory:

• Host system bus
• Client system bus
• Host key bus (private key bus)
• Client key bus (private key bus)

The host system bus is used in Emulation mode to write and read data to/from the Emulation memory instead of the OTP memory. The host system bus can only access the emulation memory.

The client system bus is available to access to the user interface.

The host key bus is available to read keys stored in the User area of the OTP memory and transfer them to the client crypto-engines connected to this bus (e.g. AES). No data accessible to the host key bus are accessible to the System bus.

The client key bus is available to write some data to the User area of the OTP memory. No data coming from the client key bus are accessible to the system bus.