The PSI5 IP-module performs communication according to the PSI5 specification V2.1 and also supports the extended powertrain substandard. PSI5 provides high speed and high reliability data transfer.

The PSI5 kernel consists of 2 independent and parallel PSI5 channels each of which support 6 sensor slots. The IP also consists of a Manchester Decoding block that decodes the received PSI5 data frames.

The Buffer Memory holds up to 32 frames per channel along with the timestamp.

The Sync + Data Pulse Generation block generates sync pulses to trigger a data frame for data acquisition from a sensor or for ECU to sensor communication.

The Timestamp Generation block offers three time bases to select from for timestamping.

PSI5 acts as a slave on the FPI bus. The Clock Control block is driven by the system clock frequency

fSPB

. The Clock Control block produces a total of 5 clock signals.

Figure 1. PSI5 block diagram

The Peripheral Sensor Interface is an interface for automotive sensor applications. PSI5 is an open standard based on existing sensor interfaces for peripheral airbag sensors, already proven in millions of airbag systems.

The PSI5 interface provides a current loop-based serial communication link typically used to connect airbag sensors or other peripheral devices.

While the physical layer is done externally, this module manages protocol handling and data representation to the application. Note that there is no on-chip PHY. The current to voltage and voltage to sync pulse translation is done externally as shown in the figure below.

Figure 2. PSI5 module connected to external PHY

Receive data on a PSI5 channel can be set up according to the underlying application. In particular the number of bits is configurable.

The message storage consists of a 32-bit buffer register for each channel and an additional 32-bit register containing the 24-bit time stamp and additional status bits. These 64 bits per frame are additionally stored in a buffer of 32 lines per channel.

In ECU to sensor communication mode, the module can provide regular sync pulses and select between internal and external timer or trigger resources. It also supports setting up the sensor and retrieving sensor status information.

The register set of the PSI5 module can be accessed directly by the CPU for configuration, data read out and status query.