The ARM Cortex-A76 is a central processing unit implementing the ARMv8.2-A 64-bit instruction set designed by ARM Holdings' Austin design centre. ARM states a 25% and 35% increase in integer and floating point performance, respectively, over a Cortex-A75 of the previous generation.[2]

ARM Cortex-A76
General information
Designed byARM Holdings
Max. CPU clock rateto 3.0 GHz in phones and 3.3 GHz in tablets/laptops 
FSB speeds100  to 104 
Address width40-bit
L1 cache128 KiB (64 KiB I-cache with parity, 64 KiB D-cache) per core
L2 cache128–512 KiB per core
L3 cache512 KiB–4 MiB (optional)
Architecture and classification
MicroarchitectureARM Cortex-A76
Instruction setARMv8-A: A64, A32, and T32 (at the EL0 only)
Physical specifications
  • 1–4 per cluster
Co-processorARM Cortex-A55 (optional)
Products, models, variants
Product code name(s)
  • Enyo
Predecessor(s)ARM Cortex-A75
ARM Cortex-A73
ARM Cortex-A72
Successor(s)ARM Cortex-A77

Design edit

The Cortex-A76 serves as the successor of the ARM Cortex-A73 and ARM Cortex-A75, though based on a clean sheet design.

The Cortex-A76 frontend is a 4-wide decode out-of-order superscalar design. It can fetch 4 instructions per cycle. And[clarification needed] rename and dispatch 4 Mops, and 8 μops per cycle. The out-of-order window size is 128 entries. The backend is 8 execution ports[clarification needed] with a pipeline depth of 13 stages and the execution latencies of 11 stages.[2][3]

The core supports unprivileged 32-bit applications, but privileged applications must utilize the 64-bit ARMv8-A ISA.[4] It also supports Load acquire (LDAPR) instructions (ARMv8.3-A), Dot Product instructions (ARMv8.4-A), PSTATE Speculative Store Bypass Safe (SSBS) bit and the speculation barriers (CSDB, SSBB, PSSBB) instructions (ARMv8.5-A).[5]

Memory bandwidth increased 90% relative to the A75.[6][7] According to ARM, the A76 is expected to offer twice the performance of an A73 and is targeted beyond mobile workloads. The performance is targeted at "laptop class", including Windows 10 devices,[8] competitive with Intel's Kaby Lake.[9]

The Cortex-A76 support ARM's DynamIQ technology, expected to be used as high-performance cores when used in combination with Cortex-A55 power-efficient cores.[2]

Licensing edit

The Cortex-A76 is available as a SIP core to licensees, and its design makes it suitable for integration with other SIP cores (e.g. GPU, display controller, DSP, image processor, etc.) into one die constituting a system on a chip (SoC).

Usage edit

The Cortex-A76 was first used in the HiSilicon Kirin 980.[10]

ARM has also collaborated with Qualcomm for a semi-custom version of the Cortex-A76, used within their high-end Kryo 495 (Snapdragon 8cx)/Kryo 485 (Snapdragon 855 and 855 Plus), and also in their mid-range Kryo 460 (Snapdragon 675) and Kryo 470 (Snapdragon 730) CPUs. One of the modifications Qualcomm made was increasing reorder buffer to increase the out-of-order window size.[11]

It is also used in the Exynos 990 and Exynos Auto V9,[12] the MediaTek Helio G90/G90T/G95 and Dimensity 800 and Dimensity 820, and the HiSilicon Kirin 985 5G and Kirin 990 4G/990 5G/990E 5G.[13][14][15]

The Cortex-A76 can be found in Snapdragon 855 as Big-core.

The Cortex-A76 is used as Big-core in Intel Agilex D-series SoC FPGA devices.[16]

In 2020 Cortex-A76 was used in Rockchip RK3588 and RK3588s.

In September 2023, the Raspberry Pi 5 was introduced with a Broadcom BCM2712 quad-core Arm Cortex-A76 processor with a clock speed of 2.4 GHz.[17]

See also edit

References edit

  1. ^ Shrout, Ryan; Moorhead, Patrick (31 May 2018). "Ep 23 - 5/31/18 - The Future of Arm with Nandan Nayampally". The Tech Analysts Podcast. Retrieved 1 June 2018.
  2. ^ a b c Frumusanu, Andrei (31 May 2018). "Arm Cortex-A76 CPU Unveiled". Anandtech. Retrieved 1 June 2018.
  3. ^ "Arm Unveils Cortex-A77, Emphasizes Single-Thread Performance". WikiChip Fuse. 2019-05-26. Retrieved 2020-06-18.
  4. ^ Williams, Chris (31 May 2018). "Arm emits Cortex-A76 – its first 64-bit-only CPU core (in kernel mode)". The Register. Retrieved 1 June 2018.
  5. ^ "ARM documentation set for Cortex-A76". Retrieved 2019-06-15.
  6. ^ Armasu, Lucian (31 May 2018). "Arm's Cortex-A76 Could Be The First True Challenger To x86 Chips On Laptops". Tom's Hardware. Retrieved 1 June 2018.
  7. ^ Triggs, Robert (31 May 2018). "Arm Cortex-A76 CPU deep dive". Android Authority. Retrieved 1 June 2018.
  8. ^ Hruska, Joel (31 May 2018). "ARM's New Cortex-A76 SoC Targets Windows Laptop Market". Extreme Tech. Retrieved 1 June 2018.
  9. ^ Bright, Peter (1 June 2018). "ARM promises laptop-level performance in 2019". Ars Technica. Retrieved 1 June 2018.
  10. ^ Frumusanu, Andrei. "HiSilicon Announces The Kirin 980: First A76, G76 on 7nm". Retrieved 2020-11-13.
  11. ^ Frumusanu, Andrei. "Arm's New Cortex-A77 CPU Micro-architecture: Evolving Performance". Retrieved 2019-06-16.
  12. ^ "Exynos 990 Mobile Processor: Specs, Features | Samsung Exynos". Samsung Semiconductor. Retrieved 2020-06-18.
  13. ^ MediaTek (2020-06-18). "MediaTek Helio G90 Series". MediaTek. Retrieved 2020-06-18.
  14. ^ MediaTek (2020-06-18). "MediaTek Dimensity 800". MediaTek. Retrieved 2020-06-18.
  15. ^ MediaTek (2020-06-18). "MediaTek Dimensity 820". MediaTek. Retrieved 2020-06-18.
  16. ^ Mark van der Zalm. "Intel Agilex D-Series FPGA White Paper". Intel. Retrieved 2022-10-20.
  17. ^ Eben Upton. "Introducing: Raspberry Pi 5!". Raspberry Pi. Retrieved 2023-10-21.