Qualcomm Hexagon

Instruction set architecture

Computing devices have instruction sets, which are their lowest, most primitive languages. Common instructions are those which cause two numbers to be added, multiplied or combined in other ways, as well as instructions that direct the processor where to look in memory for its next instruction. There are many other types of instructions.

Assemblers and compilers that translate computer programs into streams of instructions – bit streams - that the device can understand and carry out (execute). As an instruction stream executes, the integrity of system function is supported by the use of instruction privilege levels. Privileged instructions have access to more resources in the device, including memory. Hexagon supports privilege levels.

Originally, Hexagon instructions operated on integer numbers but not floating point numbers, but in v5 floating point support was added.

The processing unit which handles execution of instructions is capable of in-order dispatching up to 4 instructions (the packet) to 4 execution units every clock.

Micro-architecture

Micro-architecture is the physical structure of a chip or chip component that makes it possible for a device to carry out the instructions. A given instruction set can be implemented by a variety of micro-architectures. The buses – data transfer channels – for Hexagon devices are 32 bits wide. That is, 32 bits of data can be moved from one part of the chip to another in a single step. The Hexagon micro-architecture is multi-threaded, which means that it can simultaneously process more than one stream of instructions, enhancing data processing speed. Hexagon supports very long instruction words, which are groupings of four instructions that can be executed “in parallel.” Parallel execution means that multiple instructions can run simultaneously without one instruction having to complete before the next one starts. The Hexagon micro-architecture supports single instruction, multiple data operations, which means that when a Hexagon device receives an instruction, it can carry out the operation on more than one piece of data at the same time.

According to 2012 estimation, Qualcomm shipped 1.2 billion DSP cores inside its system on a chip (SoCs) (average 2.3 DSP core per SoC) in 2011, and 1.5 billion cores were planned for 2012, making the QDSP6 the most shipped architecture of DSP (CEVA had around 1 billion of DSP cores shipped in 2011 with 90% of IP-licensable DSP market).

The Hexagon architecture is designed to deliver performance with low power over a variety of applications. It has features such as hardware assisted multithreading, privilege levels, very long instruction word (VLIW), single instruction, multiple data (SIMD), and instructions geared toward efficient signal processing. Hardware multithreading is implemented as barrel temporal multithreading - threads are switched in round-robin fashion each cycle, so the 600 MHz physical core is presented as three logical 200 MHz cores before V5.

At Hot Chips 2013 Qualcomm announced details of their Hexagon 680 DSP. Qualcomm announced Hexagon Vector Extensions (HVX). HVX is designed to allow significant compute workloads for advanced imaging and computer vision to be processed on the DSP instead of the CPU. In March 2015 Qualcomm announced their Snapdragon Neural Processing Engine SDK which allow AI acceleration using the CPU, GPU and Hexagon DSP.

Qualcomm's Snapdragon 855 contains their 4th generation on-device AI engine, which includes the Hexagon 690 DSP and Hexagon Tensor Accelerator (HTA) for AI acceleration. Snapdragon 865 contains the 5th generation on-device AI engine based on the Hexagon 698 DSP capable of 15 trillion operations per second (TOPS). Snapdragon 888 contains the 6th generation on-device AI engine based on the Hexagon 780 DSP capable of 26 TOPS. Snapdragon 8 contains the 7th generation on-device AI engine based on the Hexagon DSP capable of 52 TOPS and up to 104 TOPS in some cases.

Software support

Operating systems

The port of Linux for Hexagon runs under a hypervisor layer ("Hexagon Virtual Machine") and was merged with the 3.2 release of the kernel. The original hypervisor is closed-source, and in April 2013 a minimal open-source hypervisor implementation for QDSP6 V2 and V3, the "Hexagon MiniVM" was released by Qualcomm under a BSD-style license.

Compilers

Support for Hexagon was added in 3.1 release of LLVM by Tony Linthicum. Hexagon/HVX V66 ISA support was added in 8.0.0 release of LLVM. There is also a non-FSF maintained branch of GCC and binutils.

Adoption of the SIP block

Qualcomm Hexagon DSPs have been available in Qualcomm Snapdragon SoC since 2006. In Snapdragon S4 (MSM8960 and newer) there are three QDSP cores, two in the Modem subsystem and one Hexagon core in the Multimedia subsystem. Modem cores are programmed by Qualcomm only, and only Multimedia core is allowed to be programmed by user.

They are also used in some femtocell processors of Qualcomm, including FSM98xx, FSM99xx and FSM90xx.

Third-party integration

In March 2016, it was announced that semiconductor company Conexant's AudioSmart audio processing software was being integrated into Qualcomm's Hexagon.

In May 2018 wolfSSL added support for using Qualcomm Hexagon. This is support for running wolfSSL crypto operations on the DSP. In addition to use of crypto operations a specialized operation load management library was later added.

Versions

There are six versions of QDSP6 architecture released: V1 (2006), V2 (2007–2008), V3 (2009), V4 (2010–2011), QDSP6 V5 (2013, in Snapdragon 800), and QDSP6 V6 (2016, in Snapdragon 820) V4 has 20 DMIPS per milliwatt, operating at 500 MHz.

Clock speed of Hexagon varies in 400–2000 MHz for QDSP6 and in 256–350 MHz for previous generation of the architecture, the QDSP5.

Processor NPU Performance GPU Performance Bandwidth Apple A18 Pro 35.0 INT8 4.454 FP16 60 GB/s M2 15.8 FP16 5.68 FP16 102 GB/s M4 38.0 INT8 9.20 FP16 120 GB/s M3 Max 35.0 INT8 32.80 FP16 300/400 GB/s M4 Max 38.0 INT8 34.08 FP16 546 GB/s M2 Ultra 31.6 FP16 53.96 FP16 800 GB/s Snapdragon SD Gen2 26 INT8 4.178 FP16 67.0 GB/s SD Gen3 34 INT8 5.548 FP16 76.6 GB/s SD Gen4 50 INT8 6.758 FP16 85.1 GB/s SD X Elite 45 INT8 9.200 FP16 133.9 GB/s

Availability in Snapdragon products

Both Hexagon (QDSP6) and pre-Hexagon (QDSP5) cores are used in modern Qualcomm SoCs, QDSP5 mostly in low-end products. Modem QDSPs (often pre-Hexagon) are not shown in the table.

QDSP5 usage:

QDSP6 (Hexagon) usage:

Hardware codec supported

The different video codecs supported by the Snapdragon SoCs.

D - decode; E - encode

FHD = FullHD = 1080p = 1920x1080px

HD = 720p which can be 1366x768px or 1280x720px

Snapdragon 200 series

The different video codecs supported by the Snapdragon 200 series.

Snapdragon 400 series

The different video codecs supported by the Snapdragon 400 series.

Snapdragon 600 series

The different video codecs supported by the Snapdragon 600 series.

Snapdragon 700 series

The different video codecs supported by the Snapdragon 700 series.

Snapdragon 800 series

The different video codecs supported by the Snapdragon 800 series.

Code sample

This is a single instruction packet from the inner loop of a FFT: { R17:16 = MEMD(R0++M1) MEMD(R6++M1) = R25:24 R20 = CMPY(R20, R8): R11:10 = VADDH(R11:10, R13:12) }:endloop0

This packet is claimed by Qualcomm to be equal to 29 classic RISC operations; it includes vector add (4x 16-bit), complex multiply operation and hardware loop support. All instructions of the packet are done in the same cycle.

References

References

1. [https://rpw.io/slides/rpw-pacsec2013-hexagon.pdf Baseband exploitation in 2013: Hexagon challenges] {{webarchive. link. (December 24, 2013 /Ralf-Philipp Weinmann Pacsec 20132013-11-14, Tokyo, Japan: "32-bit unified address space for code and data – Byte addressable; 32 General registers (32-bit) – also usable pairwise: 64-bit register pairs")
2. "CSDL {{!}} IEEE Computer Society".
3. "Hexagon DSP SDK".
4. "Hexagon DSP SDK Processor".
5. Humrick, Matt. "Qualcomm Details Snapdragon 835: Kryo 280 CPU, Adreno 540 GPU, X16 LTE".
6. "Microprocessor Report".
7. "Rob Landley's Blog Thing for 2012". Landley.net.
8. [http://llvm.org/devmtg/2011-11/Simpson_PortingLLVMToADSP.pdf Porting LLVM to a Next Generation DSP], L. Taylor Simpson (Qualcomm) // LLVM Developers’ Meeting: 11/18/2011
9. "Hexagon - Microarchitectures - Qualcomm - WikiChip".
10. Iqbal, Faisal. "Qualcomm Hexagon DSP".
11. Technologies, Qualcomm. (2018). "Qualcomm Hexagon V66 HVX Programmer's Reference Manual".
12. Will Strauss, [http://www.fwdconcepts.com/dsp111212.htm Forward Concepts. Wireless/DSP Market Bulletin: Qualcomm Leads in Global DSP Silicon Shipments] {{webarchive. link. (May 28, 2013 // Forward Concepts: "In calendar year 2011, Qualcomm shipped a reported 521 million MSM chip shipments and we estimate that an average of 2.3 of its DSP cores in each unit resulted in 1.2 billion DSPs shipped in silicon. This (calendar) year, we estimate that the company will ship an average of 2.4 DSP cores with each (more complex) MSM chip.")
13. [http://www.prnewswire.com/news-releases/ceva-continues-to-dominate-dsp-ip-market-with-90-market-share-151346395.html]; [http://www.semiwiki.com/forum/content/1287-dsp-ip-core-ceva-undisputed-worldwide-leader-70-market-share.html] {{Webarchive. link. (2015-01-14; [https://archive.today/20130722043806/http://www.eetasia.com/articleLogin.do?artId=8800667242 Ceva grabs 90% of DSP IP market], 2012)
14. Hexagon v2 Programmers Reference
15. Lucian Codrescu (Qualcomm). (March–April 2014). "Hexagon DSP: An Architecture Optimized for Mobile Multimedia and Communications". IEEE Micro 34.2.
16. [http://eprint.iacr.org/2013/428.pdf Faster 128-EEA3 and 128-EIA3 Software], Roberto Avanzi and Billy Bob Brumley (Qualcomm Research), Cryptology ePrint Archive: Report 2013/428, 2 Jul 2013. Page 9.
17. Hexagon V5 switched to dynamic multithreading (DMT) with [[Context switch#LATENCY
18. Ho, Joshua. "Qualcomm Details Hexagon 680 DSP in Snapdragon 820: Accelerated Imaging".
19. "On-Device AI with Qualcomm Snapdragon Neural Processing Engine SDK".
20. (2019-02-24). "Artificial Intelligence Engine in Qualcomm Snapdragon 855 Mobile Platform Powers On-Device AI User Experiences in Flagship Premium-Tier Smartphones".
21. (2019-12-03). "Qualcomm Introduces the World's Most Advanced 5G Mobile Platform".
22. (2020-12-01). "Exploring the AI capabilities of the Qualcomm Snapdragon 888 Mobile Platform".
23. (2020-12-01). "Snapdragon 8 Gen 1 Mobile Platform".
24. https://docs.qualcomm.com/bundle/publicresource/80-NB419-3_REV_A_Hexagin_Virtual_Machine_Specification.pdf {{Webarchive. link. (2024-05-07 (restricted access))
25. (2 November 2011). "3.2 merge window, part 1". [[lwn.net]].
26. [http://kernelnewbies.org/Linux_3.2#head-2acfe3ee1657c9c2647e5bb5d10e4f511f7527d8 Linux Kernel 3.2 Release Notes] "1.4. New architecture: Hexagon"
27. Richard Kuo, [http://permalink.gmane.org/gmane.linux.ports.hexagon/553 Hexagon MiniVM] {{Webarchive. link. (2013-12-24 // linux.ports.hexagon, 25 Apr 2013)
28. [https://www.codeaurora.org/projects/all-active-projects/hexagon-minivm Hexagon MiniVM] {{Webarchive. link. (2013-05-22 // CodeAurora (Qualcomm))
29. (2012-05-15). "LLVM 3.1 Release Notes". Llvm.org.
30. (2019-03-20). "LLVM 8.0.0 Release Notes". Llvm.org.
31. [http://www.brightsideofnews.com/news/2011/10/12/qualcomm-announces-its-2012-superchip-28nm-snapdragon-s4.aspx Qualcomm Announces Its 2012 Superchip: 28nm Snapdragon S4], 10/12/2011 by John Oram. Quote: "Hexagon DSPs have been in Snapdragon chips since 2006."
32. [http://www.bdti.com/InsideDSP/2012/06/21/Qualcomm QDSP6 V4: Qualcomm Gives Customers and Developers Programming Access to its DSP Core] // InsideDSP, June 22, 2012
33. [http://www.linleygroup.com/newsletters/newsletter_detail.php?num=4761 Qualcomm Aims Hexagon at Femtocells], October 31, 2011. Linley Gwennap// Linley WIRE
34. (2016-03-01). "Qualcomm to Integrate Conexant AudioSmart into Hexagon DSPs". Speech Tech Magazine.
35. (2018-05-18). "wolfSSL Use With Hexagon Toolchain". wolfSLS.
36. (7 January 2013). "Qualcomm Announces Next Generation Snapdragon Premium Mobile Processors". Qualcomm.
37. "List of Snapdragon SoCs". developer.qualcomm.com.
38. (August 2013). "Qualcomm Hexagon DSP: An architecture optimized for mobile multimedia and communications". Hot Chips 25.
39. [http://www.bdti.com/InsideDSP/2013/02/13/Qualcomm QDSP6 V4: BDTI Benchmark Results and Implementation Details Of Qualcomm's DSP Core] // BDTI, February 12, 2013
40. [http://www.bdti.com/InsideDSP/2013/06/13/Qualcomm Qualcomm's QDSP6 v5: Benchmarking Results Confirm That Floating-Point Support Has Arrived] // BDTI, June 12, 2013
41. "Qualcomm SDM660 SoC {{!}} Integrated LTE Application Processor based on Snapdragon 660 {{!}} Qualcomm".
42. [http://www.bdti.com/insidedsp/2015/09/30/qualcomm Qualcomm's QDSP6 v6: Imaging and Vision Enhancements Via Vector Extensions] // BDTI, September 29, 2015
43. (25 August 2015). "Qualcomm's new Hexagon 680 DSP: Fast, efficient, shipping with Snapdragon 820". Extremetech.
44. "AI-Benchmark".
45. "Reddit - The heart of the internet".
46. (23 June 2024). "Decoding AI TOPS: Essential Metrics for AI Chips and TOPS Comparison Chart {{!}} Ernest Chiang".
47. (June 13, 2024). "The Qualcomm Snapdragon X Architecture Deep Dive: Getting To Know Oryon and Adreno X1".
48. [http://www.qualcomm.com/snapdragon/processors/800-600-400-200/specs Snapdragon 800, 600, 400, 200 Processor Specs] // Qualcomm
49. (October 2, 2018). "Snapdragon 200 Processor". Qualcomm.
50. "Qualcomm 205 Mobile Platform". Qualcomm.
51. (9 September 2014). "Qualcomm unveils the Snapdragon 210 and 208 processors". Qualcomm.
52. (July 28, 2015). "Snapdragon 412 and 212 processors announced". Qualcomm.
53. "Snapdragon 400 Processor". Qualcomm.
54. "Snapdragon 415 Processor". Qualcomm.
55. (26 June 2018). "Introducing Snapdragon 632, 439 and 429 for enhanced mobile experiences, superior performance". Qualcomm.
56. (27 June 2017). "Qualcomm Snapdragon 450 Mobile Platform to Bring 14nm FinFET Process, Enhanced Dual-Camera Support and Fast LTE Connectivity to Mid-Range Smartphones and Tablets". Qualcomm.
57. (14 January 2020). "Snapdragon 460 Mobile Platform {{!}} Qualcomm".
58. (11 December 2020). "Qualcomm Snapdragon 480 5G Mobile Platform {{!}} Qualcomm".
59. (December 2015). "Snapdragon 600 tier processors repositioned to reflect advanced performance". Qualcomm.
60. "Snapdragon 610 Processor". Qualcomm.
61. "Qualcomm Snapdragon 660 and 630 Mobile Platforms Drive Advanced Photography, Enhanced Gaming, Integrated Connectivity and Machine Learning". Qualcomm.
62. (14 January 2020). "Snapdragon 662 Mobile Platform". Qualcomm.
63. (27 March 2019). "Snapdragon 665 Mobile Platform". Qualcomm.
64. (2 October 2018). "Snapdragon 670 Mobile Platform {{!}} Qualcomm".
65. (2 June 2020). "Snapdragon 690 5G Mobile Platform". Qualcomm.
66. "Kodi Codec SoC Hardware-Support".
67. "Snapdragon 630 Mobile Platform with X12 LTE and Spectra 160 ISP {{! }} Qualcomm". Qualcomm.
68. "Snapdragon 660 Mobile Platform with Spectra ISP and Hexagon 680 DSP {{! }} Qualcomm". Qualcomm.
69. "Snapdragon 710 Mobile Platform". Qualcomm.
70. (22 January 2019). "Snapdragon 712 Mobile Platform {{!}} Qualcomm".
71. (14 January 2020). "Snapdragon 720G Mobile Platform". Qualcomm.
72. (13 March 2019). "Snapdragon 730 Mobile Platform {{!}} Qualcomm".
73. (17 August 2020). "Snapdragon 732G Mobile Platform {{!}} Qualcomm".
74. (19 November 2019). "Snapdragon 765 5G Mobile Platform {{!}} Qualcomm".
75. (May 2020). "Snapdragon 768G 5G Mobile Platform {{!}} Qualcomm".
76. "Snapdragon 778G 5G Mobile Platform".
77. "Snapdragon 780G 5G Mobile Platform".
78. Shimpi, Anand Lal. "The Difference Between Snapdragon 800 and 801: Clearing up Confusion".
79. (20 November 2013). "Qualcomm Technologies Announces Next Generation Qualcomm Snapdragon 805 "Ultra HD" Processor". Qualcomm.
80. "Qualcomm's Snapdragon 808/810".
81. [https://www.qualcomm.com/news/snapdragon/2016/01/05/first-snapdragon-820-powered-smartphone-announced-ces First Snapdragon 820 powered smartphone announced at CES] {{Webarchive. link. (January 5, 2017 – Qualcomm.com, January 5, 2016)
82. "Snapdragon 835 Mobile Platform". Qualcomm.
83. "Snapdragon 845 Mobile Platform". Qualcomm.
84. (7 November 2018). "Snapdragon 855 Mobile Platform". Qualcomm.
85. (19 November 2019). "Snapdragon 865 5G Mobile Platform". Qualcomm.
86. (17 November 2020). "Snapdragon 888 5G Mobile Platform". Qualcomm.
87. (2018-12-05). "How Qualcomm improved Performance, Gaming, and AI on the Snapdragon 855".
88. Snapdragon 820. (2016). "Snapdragon 820 product brief".
89. "snapdragon-820-processor-product-brief.pdf {{! }} Graphics Processing Unit {{! }} Electronics".
90. "Eragon Snapdragon 820 SOM (APQ8096) - Based on Qualcomm® Snapdragon 820 (APQ8096) Series Processor for Embedded Systems".
91. (2018-12-05). "Qualcomm Spectra 380 Launched: World's First ISP With Integrated AI".
92. (2018). "Product Brief Snapdragon 845".
93. (2018). "Product Brief Snapdragon 845".