Using PCIe in Mobile Devices Ofer Rosenberg Senior Staff Engineer Qualcomm Israel LTD

Transcription

1 Using in Mobile Devices Ofer Rosenberg Senior Staff Engineer Qualcomm Israel LTD 1

2 Disclaimer Presentation Disclaimer: All opinions, judgments, recommendations, etc. that are presented herein are the opinions of the presenter of the material and do not necessarily reflect the opinions of the PCI-SIG. 2

3 Contents Introduction: at Qualcomm Technologies Inc. (QTI) Case Study in MDM QTI Perspective Qualcomm Snapdragon is a product of Qualcomm Technologies Inc. 3

4 Importance to QTI QTI ships around a Billion Application Processors each year Each has one or more Root Complexes Key interface for communicating with Modem/Wi-Fi devices QTI ships XX Modem devices each year Connect as end-points Key interface for connecting the device to QTI or 3 rd Party Application Processors 4

5 Few years ago, QTI identified the need for long-term solution for highspeed Chip-to-Chip (C2C) connection TPT (bps) Motivation Modem, Wifi and Storage speeds increase Existing serial interfaces speed became a bottleneck Needed a long term, evolving, high speed interface which will meet future speed increase a n (20MHz) n (40MHz) ac (wave1) ac (wave2) 54M 300M 600M 1.3G 6.7G Max DL rate (bps) WCDMA HSPA HSPA+ LTE CAT 3 CAT 5 CAT K 14M 28M 100M 300M 450M Max UL rate (bps) 128K 5.7M 11M 51M 75M 100M was chosen due to its extendibility, design philosophy, features and power management capabilities 5

6 at QTI QTI develops both Root-Complex and End-Point Root Complex: Qualcomm Snapdragon Application Processors provide Root-Complex Port/s Qualcomm Server Chips will arrive with Multiple Root Complex Ports End-Point: Qualcomm Gobi Modems connect as EP WLAN Devices connect using EP WiGig Devices connect using EP Other QTI Three Pillars of use High-End C2C High-End Expansion Bus Embedded /Mobile C2C * Qualcomm Gobi is a product of Qualcomm Technologies Inc. 6

7 Mobile Device Chipset Audio Codec Application Processor Modem Storage Wi-Fi Camera WiGig Display 7

8 Case Study in Mobile Data Modem (MDM) Chipset (at system level, including L1ss) 8

9 in Mobile Devices Example for Common Usage: Application Processor connected to External Modem Samsung Galaxy Note 4 9

10 Smart Devices Advantage devices are smart Access different entities inside the SoC (pending on access rights) Autonomously handle data transfers (reads and writes) The Direct & Autonomous access has SoC power management advantages Access Modules & DDR without waking the CPU Access Modules with standalone memory without waking the DDR DDR Mem Interface CPU Modem Chipset Module B Module A SMMU RAM RC EP Application Processor 10

11 Typical LTE Activity LTE works in Bursts of 1mSec The device issues a burst of data write (downlink) and read (uplink), and then remains silent until next subframe Burst length depends on generation (CAT 1-10) Ideal for smart devices which know to handle power states subframe 1mSec #0 #1 #2 #3 #18 #19 Radio Frame 10mSec CAT 1 CAT 2 CAT 3 CAT 5 CAT 10 Max DL rate (bps) Max UL rate (bps) 10M 50M 100M 300M 450M 5M 25M 51M 75M 100M 11

12 Power States Link Initialization L3 L0s FTS Active EIOS L0 PM Msgs. Power ON L2/L3 Ready Power OFF Tx Idle ASPM Msgs. Link Recovery WAKE# Vaux L2 PLL / PIPE RX Idle Detect L0 On On On L1.0 Off On On L1.1 Off Off On L1Mode Substates L1.2 Off Off Off Tx Comn CLKREQ# De-Assert LTR < Threshold L1.1 CLKREQ# Assert L1 (L1.0) CLKREQ# Assert CLKREQ# De-Assert LTR >= Threshold L1.2 12

13 Race to Idle Philosophy The Basics L1.2àL0 L0 L0àL1.0 L1.0 L1.0àL1.1 L1.1 Resume Transmit as fast as possible ( 1/2/3 ) Go back to low-power state L1.2 The Challenges Buffering UL/DL sync Correctly Select L1.1 / L1.2 Link 1mSec. 1mSec. 1mSec 13

14 System Perspective Link inactivity Short intervals, such as 1mSec frames Longer intervals due to data link inactivity Power management is a joint HW-SW effort HW manages short interval transitions (L1ss L0) Host / SW manages deeper transitions (D0 D3/L2) Host & Device in Low Power Host : Low Power Device : Low Power : D3cold / L2 Device enters/exists Low power Device in Low Power Normal Operation Host in Low Power Host : ON Device : Low Power : D0 / L1ss Device enters/exists Low power Host : ON Device : ON : D0 / ASPM Host enters/exists Low power Host : Low Power Device : On : D3cold / L2 14

15 SUMMARY 15

16 QTI Perspective Full-Fledge topology QTI Mobile typical usage Host CPU Application Processor Root Root Root Switch EndPoint EndPoint EndPoint EndPoint Switch EndPoint EndPoint EndPoint PCI Adapter Bridge PCI-X Adapter Single Bus/Device per RC (Very) Short links Frequent switch between Active & Low-Power 16

17 QTI Perspective What do we like in? Highly extendable interface, from 2.5 GT/s x1 to 8 GT/s x16 Philosophy of Smart devices: Initiate data transactions Handle power state changes Advanced capabilities (TC, MSI, TPH, ATS, IOV and more ) Low-Power States What would we like to enhance in? Optimized behavior for Low-Power / Chip-to-Chip scenarios Revisit Legacy features (such as ECAM) Revisit LTSSM, up/down link time, etc. Enhanced support in interconnect fabrics Example: Ordering Rules 17

18 QTI Vision for Power States transitions cleanup (redundant states, reduce min. duration) Improve Support in Advanced System Buses Optimize Chip-to-Chip scenarios Standardize handling of Host power states More 18

19 TIME FOR QUESTIONS 19

20 Disclaimer Qualcomm Snapdragon and Gobi are trademarks of Qualcomm Incorporated, registered in the United States and other countries, used with permission. Other product and brand names may be trademarks or registered trademarks of their respective owners 20

21 Thank you for attending the Israel 2015 For more information please go to 21