Qualcomm 8295 cockpit domain control DHU internal basic structure

Zos Automotive Research Institute disassembled the cockpit domain controller based on the 8295 chip of an electric car launched in December 2023, and formed a report "Analysis and Disassembly of SA8295P Series Cockpit Domain Controller". The official name of the cockpit domain controller is "Driving Information and Entertainment Head Unit (DHU)", and the full English name is "Digital Cockpit Head Unit". The cockpit domain controller has two versions, high and low, both of which use Qualcomm SA8295P chips and are supplied by Aptiv. From the perspective of cost disassembly, the total cost of the two differs by tens of dollars.

The one disassembled by Zoss Automotive Research this time is a low-end version. This article will make a rough disassembly and analysis of the basic overview of the DHU, the main control chip, storage, MCU and radio parts.

Basic Information

In terms of appearance, the DHU is relatively thick and has three black rectangular blocks, corresponding to a Bluetooth and WiFi system, a pure Bluetooth system and a radio system.

The reason why it is thicker is that the DHU adopts a two-layer PCB design, connected via B2B. The upper board is responsible for cockpit entertainment and instrumentation, while the lower board is responsible for camera input, display output, microphone reception, etc.

The basic internal structure of the cockpit domain control DHU

Image source: Zoss Automotive Research

Main control chip and storage

The core board is mounted on the upper board and is equipped with QAM8295P and 6 main chips, including 4 power management chips Qualcomm PMM8295AU and 2 DRAM chips.

Cockpit domain control DHU core board and storage chip

Image source: Zoss Automotive Research

In terms of storage, the DHU is equipped with DRAM chips and NAND chips.

Among them, the DRAM chip is Micron LPDDR4, the FBGA Code is D9ZRT, and the clock frequency is 2133MHz, which is the lowest specification in LPDDR4 and also the lowest-priced automotive-grade LPDDR4. The high-end version has a core board with 32GB of memory, which may be LPDDR4X.

The NAND storage uses Samsung's UFS2.1 solution, model KLUEGAJ1ZD-B0CP, which is a common type product for mobile phones and cars, with a voltage of 1.8/3.3V, a temperature resistance of -40℃~85℃, and a capacity of 256GB. The chip is arranged outside the core board.

MCU

The DHU version disassembled this time uses Renesas' R7F7017113 MCU, which belongs to the Renesas RH850/F1KH series, 233 pins, and a temperature resistance of -40℃~105℃. The high-end version of DHU uses Infineon's TC387 as its MCU.

Renesas RH850/F1KH-D8 (233-Pin) Internal Block Diagram

Image source: Renesas

Ethernet

In terms of Ethernet, there are differences in configuration between the high-end and low-end versions. Specifically, the high-end version has an Ethernet switch, while the low-end version only has an Ethernet physical layer chip. The PCB boards of the two versions are the same, except that the low-end version has a space on the surface of the Ethernet area and no patch is performed.

Cockpit domain control DHU Ethernet chip layout area

Image source: Zoss Automotive Research

According to the disassembly, the Ethernet physical layer chip is Marvell's 88Q2122, which is a 100/1000BASE-T1 Ethernet physical layer transceiver (PHY) based on the IEEE 802.3bw and IEEE 802.3bp definitions, which realizes signal transmission on a single twisted pair. Using standard digital CMOS technology, combined with all the required internal active circuits, it realizes the simultaneous reception and transmission of data on a pair of twisted pairs, which is very suitable for a variety of in-vehicle applications. The 88Q2122 integrates the terminal matching resistors required for the media-dependent interface (MDI), which simplifies the motherboard layout and reduces the cost of the motherboard by reducing the number of external components. Its internal integrated linear regulator can generate all the required voltages, and only one 3.3V power supply is required to operate. Both solutions support 1.8V, 2.5V and 3.3V LVCMOS I/O standards.

Radio

The radio chip is mainly arranged on the lower PCB board. You can see that there are many reserved chip positions, mainly for export considerations.

The radio chip of the domain controller uses NXP SAF7750EL, which can correspond to AM/FM in most countries around the world. However, if DAB radio is required, TEF3100 or TEF3200 needs to be added. The overseas version of the radio main chip is generally SAF4000. SAF4000 is a fully integrated software-defined radio solution launched by NXP in 2017, which is compatible with all global broadcast audio standards including AM/FM, DAB+, DRM(+) and HD.

Cockpit domain control DHU lower board radio chip layout area

Image source: Zoss Automotive Research