Andes晶心科技扩展并升级旗下RISC-V产品 (参考翻译)

By Bob Wheeler (February 1, 2021)

晶心科技为其超标量RISC-V处理器新增加多核系列,创建了迄今为止最强大的处理器集群。AX45MP锁定不同领域的高阶应用,例如AR / VR(增强现实/虚拟现实),人工智能边缘计算(egde AI),车载信息娱乐系统和先进驾驶辅助系统(ADAS),视频处理,高速联网以及高阶存储装置。晶心科技于2020年第三季发表了该系列的单核RTL并已获得了多个订单,而支持多核的45MP系列也于2021上半年全面上市。除了64位的AX45MP之外,也包括32位A45MP。晶心科技这次所推出最新旗舰级RISC-V多核处理器和SiFive在之前推出的U74MC处理器瞄准同一量级应用,为竞争对手。

在这个等级的集群产品中,A45MP和AX45MP跟晶心科技在2019年所发布的标题核A25MP和AX25MP相似(请参阅MPR 4/15/19 “Andes Strengthens Its RISC-V Arsenal”)。这个多核集群,可支持最多4个CPU核,搭配Coherence Manager和可选用的L2缓存控制器,并为SoC的其余部分提供一个128位AXI主接口。Coherence Manager采用目录式协议(directory-based protocol)以取代25多核系列的窥探式协议(snooping protocol),也提供了一个用于输入/输出(I / O)的AXI-128从端口(slave port),其宽度是25系列的两倍。每个中央处理器都配置一个可用于区域内存的AXI从端口。多核集群也包括调试的支持以及平台级中断控制器(PLIC)。

45系列为晶心科技第一个超标量(superscalar)中央处理器,相较于25系列的5阶流水线设计,45系列则提供达8阶的流水线设计。这些中央处理器透过256条分支目标缓冲区(branch target buffer)来执行动态预测。晶心科技45系列和SiFive的7系列一样,顺序执行管道都包含两个“后期”的算术逻辑单元(late ALUs)来消除负载使用上的损失。(请参阅MPR 11/12/18, “SiFive Raises RISC-V Performance”)。这个方法让2个有相依性的ALU指令能够与加载的数据指令在同个周期内发出。单独的两周期乘法器已完全流水线化。晶心科技估测AX45为每兆赫5.50 CoreMarks,较AX25提升了56%。在28纳米的制程技术,此中央处理器频率速度在 worst-case条件下可达到1.2GHz,而于12纳米的制程技术,在typical-case条件下可达到2.4GHz。

晶心科技45系列强化了很多性能,例如MemBoost,这个功能首度出现于带有向量(RVV)扩展指令的NX27V中(请参阅MPR5/25/20,“Andes Plots RISC-V Vector Heading”)。45系列包含指令及数据预取、支持多个未完成(multiple outstanding)的数据存取和能够绕过缓存的动态写入法则。为了处理虚拟内存,A45和AX45都带有内存管理单元(MMU)和共享的转译后备缓冲区(TLB),转译后备缓冲区(TLB)可配置32到512条目。另外,45系列也提供了最多达16区的物理内存保护(PMP)。客户可以将AX45的物理地址配置为38位(SV39)或47位(SV48),而A45则受限于34位物理地址(内存可寻址达16GB)。

晶心科技AX45MP的直接竞争对手是SiFive的U74MC。SiFive的U74MC是一个具备L2缓存控制器和SMP-Linux 兼容性的64位RISC-V多核集群。尽管两者的流水线数目设计相似,但是SiFive估测他们的设计下每兆赫少于5.1 CoreMarks,并且需要在7纳米制程的技术才能够在typical-case下达到2.3GHz频率速度。我们认为AX45和U74有着相似的面积,因此晶心科技应该在每平方毫米CoreMarks中较具有优势。但在另一方面,U74MC最多能扩展到9个中央处理器(CPU),而SiFive同意客户能够在集群(cluster)中混合应用型中央处理器(application CPUs)及实时中央处理器(real-time CPUs)。AX45的特别之处在于能同时支持区域内存(TCM)及数据高速缓存器,而SiFive的客户只能两者选其一支持。AX45的47位物理地址(PA)也是独一无二的,但我们预期是在设计多芯片一致性互连架构下才需要超过38位的物理地址。
尽管SiFive确实被视为RISC-V的先驱,但晶心科技却是第一个供应RISC-V指令集CPU IP 的上市公司。在过去几年,晶心科技将RISC-V产品从微控制器核扩展到具备DSP、向量(Vector)和浮点运算单元的嵌入式核。AX45和 ARM 所推出的“小核” Cortex-A53 在市场相同级别竞争。晶心RISC-V近期的订单,包括瑞萨(Renesas)物联网芯片、比科奇(Picocom)5G基频处理器及一些使用NX27V核的但未公开发表的AI加速器客户。AX45MP提供了适合SMP Linux的高效率-面积(area-efficient)中阶集群,从而实现了晶心科技以往无法达到的更复杂功能的SoC设计。

原文链接:http://www.andestech.com/wp-content/uploads/Andes-Scales-Up-Its-RISC-V.pdf

Continue ReadingAndes晶心科技扩展并升级旗下RISC-V产品 (参考翻译)

Andes certifies Imperas RISC-V Reference Models for the new RISC-V P (SIMD/DSP) extension

Imperas simulation technology and RISC-V reference models updated to cover the RISC-V P Extension for SoC architecture exploration and early software development

Andes Certifies Imperas RISC-V Reference Models For The New RISC-V P (SIMD/DSP) Extension

Oxford, United Kingdom, July 12th, 2021Imperas Software Ltd., the leader in virtual platforms and high-performance software simulation, today announced that Andes Technology Corp., a leading supplier of performance-efficient and extensible 32/64-bit RISC-V CPU cores and a Founding Premier member of the RISC-V International Association, has certified the Imperas reference models for the complete range of Andes IP cores with the new RISC-V P extension. Developers can now use the Imperas reference models to evaluate multicore design configuration options for SoC architecture exploration.

The open standard RISC-V ISA (Instruction Set Architecture) has a modular structure based on multiple independent extensions that offer dedicated and enhanced functionality to optimize a processor for the target application. The new SIMD/DSP extension, designated as ‘P’ in the specification description, supports efficient data processing applications and real-time requirements. The RISC-V International P Extension Task Group is in the final stages of submitting the specification to the official ratification process, which is expected to be completed within H2 2021.

The Imperas simulation technology enables fast and accurate virtual platforms that are central to modern SoC design and embedded software development. Working with lead customers, the Imperas models of the Andes cores have already been used for commercial projects, which are now implemented in silicon.

Optimizing a multicore design is one of the most challenging design tasks. Multiple independent processing units interacting with each other plus shared peripherals together with real-time processing tasks supporting a mix of OS/RTOS running firmware and application software. SoC architecture exploration allows a full evaluation of software running before the final decision and configuration of the hardware options. These virtual prototypes also support early software development, often many months before silicon prototypes are available. For final software testing, a virtual platform allows the actual binary code to be verified with access and visibility not available in real hardware or without compromising the software under test with additional test code.

“RISC-V is more than an ISA specification, it is a framework of flexibility; the real value is in the extensions and options available for processor core implementations,” said Dr. Charlie Su, President and CTO at Andes Technology Corp. “The RISC-V P extension within the Andes cores addresses the key real-time requirements in SIMD/DSP computations for new markets in audio/speech, IoT, tinyML and edge devices. Together with the Andes certified Imperas reference models, SoC developers can explore the next generation domain-specific solutions.”

“Embedded development depends on the optimized balance between hardware resources and software applications,” said Simon Davidmann, CEO at Imperas Software Ltd. “With the Imperas golden reference models, developers can explore full software development for all the Andes cores, including the new RISC-V P extension and Andes ACE custom instructions.”


About Andes Technology
Sixteen years in business and a Founding Premier member of RISC-V International, Andes is a leading supplier of high-performance/low-power 32/64-bit embedded processor IP solutions, and a main force to take RISC-V mainstream. Andes’ fifth-generation AndeStar™ architecture adopted the RISC-V as the base. Its V5 RISC-V CPU families range from tiny 32-bit cores to advanced 64-bit cores with DSP, FPU, Vector, Linux, superscalar, and/or multicore capabilities. The annual volume of Andes-Embedded SoCs has exceeded 2 billion since 2020, and the cumulative volume has reached 7 billion. For more information, please visit https://www.andestech.com. Follow Andes on LinkedIn, Twitter, Facebook and YouTube!

About Imperas
Imperas is the leading provider of RISC-V processor models, hardware design verification solutions, and virtual prototypes for software simulation. Imperas, along with Open Virtual Platforms (OVP), promotes open source model availability for a spectrum of processors, IP vendors, CPU architectures, system IP and reference platform models of processors and systems ranging from simple single core bare metal platforms to full heterogeneous multicore systems booting SMP Linux. All models are available from Imperas at www.imperas.com and the Open Virtual Platforms (OVP) website.

For more information about Imperas, please see www.imperas.com. Follow Imperas on LinkedIn, twitter @ImperasSoftware and YouTube.

Continue ReadingAndes certifies Imperas RISC-V Reference Models for the new RISC-V P (SIMD/DSP) extension