基於Qualcomm 8295的座艙域控制器拆解分析

ResearchInChina對2023年12月推出的電動轎車基於8295的座艙域控制器進行了拆解，並創作了 "SA8295P Series Based Cockpit Domain Controller Analysis and Dismantling" 報告。

座艙域控制器的正式名稱是 "Digital Cockpit Head Unit（DHU）" 。座艙域控制器有上配置和下配置兩個版本，均採用Qualcomm SA8295P晶片。如果你看一下成本明細，兩者的總成本相差很大，高達幾十美元。

此次，ResearchInChina拆解了較低配置版本。在本報告中將提供 DHU 概述、主晶片、儲存、MCU 和無線的粗略細分。

概述

DHU 很厚，有三個黑色矩形塊，支援Bluetooth-Wi-Fi 系統、僅Bluetooth系統和無線系統。

之所以這麼厚，是因為DHU採用了上下PCB B2B連接的兩層結構。上層PCB負責駕駛艙娛樂和集群。

底部PCB負責攝影機輸入、顯示輸出、麥克風拾音等功能。

主控晶片、儲存

核心板PCB安裝在頂部PCB上，有包括QAM8295P在內的六個主要晶片、四個電源管理IC（Qualcomm PMM8295AU）和兩個DRAM晶片。

儲存方面，DHU配備了DRAM晶片和NAND晶片。

DRAM晶片是Micron LPDDR4。FBGA代碼為D9ZRT，時脈頻率為2,133MHz，為LPDDR4的最低規格。它也是價格最低的汽車級 LPDDR4。對於更高配置的版本，核心板記憶體為32GB，可能是LPDDR4X。

NAND記憶體是Samsung的UFS2.1解決方案（型號：KLUEGAJ1ZD-B0CP），是手機和汽車的通用產品。電壓1.8/3.3V，耐溫-40℃至85℃，容量256GB。它部署在核心板外部。

單晶片

這次拆解的DHU版本的MCU是Renesas R7F7017113，屬於Renesas RH850/F1KH系列，有233個接腳，可以承受-40℃到105℃的溫度。

乙太網路

高配置版本和低配置版本在乙太網路方面有很大區別。具體來說，高配置版本有乙太網路交換機，低配置版本只有乙太網路物理層晶片。兩個版本的PCB相同，但配置較低的版本在乙太網路區域表面有空位，未實現。

根據拆解，乙太網路物理層晶片為Marvell 88Q2122。該晶片是 IEEE 802.3bw 和 IEEE 802.3bp 定義的 100/1,000BASE-T1 乙太網路物理層收發器 (PHY)，允許透過雙絞線傳輸訊號。它採用標準數位 CMOS 技術並與所有必要的內部主動電路相結合，能夠透過雙絞線同時接收和傳輸數據，使其非常適合多種汽車應用。

88Q2122內部整合了媒體相關介面（MDI）所需的匹配終端電阻，透過使用更少的外部元件簡化了主機板佈局並降低了主機板成本。內建線性穩壓器可以產生您所需的所有電壓。只需外部3.3V電源即可運作。兩種解決方案均支援 1.8V、2.5V 和 3.3V LVCMOS I/O 標準。

無線晶片部署在底部PCB上。可以看到很多晶片的部位都是固定的，主要是用來出口。

此網域控制器中的無線電晶片是NXP SAF7750EL，支援大多數國家的AM/FM。但是，如果您需要 DAB 收音機，則需要新增 TEF3100 或 TEF3200。國外版本的主要無線電晶片一般為SAF4000，這是NXP於2017年推出的全整合軟體定義無線電解決方案。SAF4000 支援全球所有廣播音訊標準，包括 AM/FM、DAB+、DRM(+) 和 HD。

在本報告中，我們拆解了一款基於Qualcomm 8295的座艙域控制器，並分析了其內部主要部件。

目錄

第一章 分解

• 外觀結構
• 內部結構
• 界面
• 外殼內部結構
• 印刷電路板

第 2 章 上 PCB 正面主要元件

• 記憶體晶片
• 單晶片
• 乙太網路晶片
• 序列器、解串器

第三章 上PCB背面主要元件

• Bluetooth、Wi-Fi
• 公車對講機
• 音訊晶片
• 其他晶片

第 4 章 下 PCB 正面主要元件

• 反序列化晶片
• 無線晶片
• 低電壓總線延長器

第五章 主要參數及概算費用

• 主控晶片框圖
• SA8155/SA8255/SA8295參數對照表
• MCU內部框圖
• 乙太網路交換器的內部框圖
• 高配置版本的序列化和反序列化配置
• 無線和音訊架構圖
• 高配版本無線拓撲
• 主要零件型號及價格

ResearchInChina dismantled 8295-based cockpit domain controller of an electric sedan launched in December 2023, and produced the report SA8295P Series Based Cockpit Domain Controller Analysis and Dismantling.

The official name of the cockpit domain controller is "Digital Cockpit Head Unit (DHU)". The cockpit domain controller has two versions, high configuration and low configuration, both of which use Qualcomm SA8295P chips. In terms of cost breakdown, their total cost differs greatly, up to tens of US dollars.

What ResearchInChina dismantled this time is the low configuration version. This article carries out a rough dismantling analysis on the DHU, involving overview, master chip, storage, MCU and radio.

Overview

The DHU looks thick, with three black rectangular blocks, corresponding to a Bluetooth-WiFi system, a Bluetooth-only system, and a radio system.

The reason why it is thick is that the DHU adopts the two-layer design of upper and lower PCBs which are connected via B2B. The upper board is responsible for cockpit entertainment and cluster.

As concerns function, the lower board is responsible for providing such functions as camera input, display output, and microphone pickup.

Master Chip and Storage

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

In terms of storage, the DHU packs DRAM and NAND chips.

Wherein, the DRAM chip is Micron LPDDR4. The FBGA Code is D9ZRT and the clock frequency is 2133MHz, the lowest specifications in LPDDR4. It is also the lowest-priced automotive grade LPDDR4. As for the high configuration version, the core board memory is 32GB and may be LPDDR4X.

The NAND memory is Samsung's UFS2.1 solution (model: KLUEGAJ1ZD-B0CP), a general-purpose product for mobile phones and automobiles. It features voltage of 1.8/3.3V, resistance to temperatures of -40-degree C~85-degree C, and capacity of 256GB. It is deployed outside the core board.

MCU

In the DHU version disassembled this time, the MCU is Renesas R7F7017113, which belongs to Renesas RH850/F1KH series, has 233 pins, and can resist temperatures of -40-degree C~105-degree C. The high configuration version of the DHU uses Infineon TC387 as its MCU.

Ethernet

The high and low configuration versions vary greatly in terms of Ethernet. Specifically, the high configuration version has an Ethernet switch, while the low configuration version only has an Ethernet physical layer chip. The PCB of the two versions is the same, except that the low configuration version leaves space on the surface of the Ethernet area, not mounted.

According to the dismantling, the Ethernet physical layer chip is Marvell 88Q2122. This chip is a 100/1000BASE-T1 Ethernet physical layer transceiver (PHY) defined by IEEE 802.3bw and IEEE 802.3bp, enabling signal transmission on a twisted pair. Using standard digital CMOS technology, combined with all internal active circuits required, it can simultaneously receive and send data on a twisted pair, which is very suitable for multiple automotive applications.

88Q2122 internally integrates the matched termination resistors required for the media-dependent interface (MDI), thereby simplifying the motherboard layout and lowering the motherboard cost as fewer external components are used. Its built-in linear regulator can generate all voltages required. It only needs a 3.3V external power supply to run. Both solutions support 1.8V, 2.5V and 3.3V LVCMOS I/O standards.

The radio chip is deployed on the lower PCB. It can be seen that there are many positions reserved for chips, mainly on account of export.

The radio chip of this domain controller is NXP SAF7750EL, which can correspond to AM/FM in most countries. Yet if the DAB radio is needed, TEF3100 or TEF3200 will need to be added. The main radio chip of the overseas version is generally SAF4000, a fully integrated software-defined radio solution launched by NXP in 2017. SAF4000is compatible with all global broadcast audio standards including AM/FM, DAB+, DRM(+) and HD.

Table of Contents

1 Disassembly

• 1.1 Appearance and Structure
• 1.2 Internal Structure
• 1.3 Interfaces
• 1.4 Internal Structure of Housing
• 1.5 PCBs

2 Main Components on the Front of the Upper PCB

• 2.1 Memory Chip
• 2.2 MCU
• 2.3 Ethernet Chip
• 2.4 Serializer and Deserializer

3 Main Components on the Back of the Upper PCB

• 3.1 Bluetooth and WiFi
• 3.2 Bus Transceiver
• 3.3 Audio Chip
• 3.4 Other Chips

4 Main components on the Front of the Lower PCB

• 4.1 Deserialization Chip
• 4.2 Radio Chip
• 4.3 Low-voltage Bus Extender

5 Key Parameters and Estimated Cost

• 5.1 Block Diagram of Master Chip
• 5.2 SA8155/SA8255/SA8295 Parameter Comparison Table
• 5.3 Internal Block Diagram of MCU
• 5.4 Internal block diagram of Ethernet Switch
• 5.5 Serialization and Deserialization Configurations of High Configuration Version
• 5.6 Radio and Audio Architecture Diagram
• 5.7 Radio Topology of High Configuration Version
• 5.8 Key Component Models and Prices