Development of a SMARC module for an ADAS system based on the i.MX8 processor

The thesis work places itself as part of a European Project called Autodrive. This project includes several company of the automotive sector with the aim to advance in the Autonomous vehicle field. This goal will be reached by improving and giving more capabilities to Advanced Driver-Assistance systems (ADAS). This type of applications have to comply with stringent automotive constraints about safety, while coping with the need of a large bandwidth: cameras produce a large amount of data that has to be transmitted and processed. The thesis work has been hosted by an Italian company called Ideas&Motion, active in the automotive field by providing engineering services and consultancy. They have been assigned by one of the partners to design and provide a developing and testing platform for ADAS systems. Such a system will be mounted on a particular vehicle equipped with all needed sensors. The processor to be used was requested to be the i.MX8 Quad Max manufactured by NXP, that features 6 Arm Cores and 2 GPUs together with an automotive grade. It has many of the modern interfaces found in a PC, like HDMI, Display Port, PCIe, SATA, USB 3.0 and GigaBit Ethernet among the others. The developing platform has been split in two different boards: a System On Module with the iMX8 (this thesis content) and a carrier board hosting it. During the first phases of the design, it has been chosen to design a board that could be reused in other project than this one. It has been chosen to adhere to an already defined standard of System On Module such that interoperability would be easier to satisfy. Among several possibilities, the Smart Mobile ARChitecture (SMARC) has been chosen. It is a free and open standard maintained by the Standard Group of Embedded Technologies (SGET), moreover it includes several modern high-speed interfaces compatible with the iMX8. The System On Module has physical dimensions of 82mmx50mm and it is intended to be inserted in a MXM3 connector, with a total of 314 pins. A complete SMARC module would be suitable for the Autodrive project. Thus, the new purpose of the project has become the design of a SMARC board. The design started by studying and understanding all the standard interfaces. In particular the focus has been on their purpose and usage, then their architecture: whether point-to-point connection, half/full duplex, multi/single master for instance. The following step has been to understand their physical layer: the number of signals, the kind of driver used, whether they were single-ended or differential lines, the required characteristic impedance and so on. This workflow has been followed for the LPDDR4, PCIe, Ethernet, HDMI, DisplayPort, SATA, USB, CSI, DSI, I2S and SD. Then there has been a study and research of the other needed components, like the DRAMs, the eMMC, the voltage regulators, the Ethernet PHYs, the USB HUB and the PCIe clock generator. The general architecture has been then defined: the Module will have 6GB of LPDDR4 SDRAM, 32 GB of storage from the eMMC, 2 PCIe Gen 3.0 lanes, 2 Gigabit Ethernet ports, 5 USB ports, one DisplayPort or one HDMI, one on-module WiFi and Bluetooth adapter, one uSD socket on the module and one SD interface to the carrier. The final result consists in the schematic of the board, developed with Mentor Xpedition keeping in mind the requirements of the iMX8, SMARC standard, and interface standards.