Tag Archives: ARM based Cortex M7

Digital audio recording “you” with quality and ease

Instamic Pro Features and Functionality

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MEMS Microphone Specifications

Recorder Specifications

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Frequency Response Specifications

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Comparison Specifications

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Comparisons at Scale

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Once again, Instamic originally stems from the well-funded pool of contributing patrons. The community has supported and validated this product’s potential for an ideal application to market fit. With this said, the demand is real. Shoot for the stars, right? Powered by Atmel’s latest Cortex-M7, Instamic is looking to become a household name when it comes to capturing high-quality sound anywhere, at anytime, on anything.

Are you designing for the latest automotive embedded system?

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Eventually, self-driving cars will arrive. But until then, here’s a look at what will drive that progression.

The next arrow of development is set for automotive

We all have seen it. We all have read about it in your front-center technology news outlets. The next forefront for technology will take place in the vehicle. The growing market fitted with the feature deviation trend does not appeal to the vision of customizing more traditional un-connected, oiled and commonly leveraged chassis vehicles of today. Instead, ubiquity in smartphones have curved a design trend, now mature while making way for the connected car platform. The awaiting junction is here for more integration of the automotive software stack. Opportunities for the connected car market are huge, but multiple challenges still exist. Life-cycles in the development of automotive and the mobile industry are a serious barrier for the future of connected cars. Simply, vehicles take much longer to develop than smartphones other portable gadgetry. More integration from vendors and suppliers are involved with the expertise to seamlessly fit the intended blueprint of the design. In fact, new features such as the operating system are becoming more prevalent, while the demand for sophisticated and centrally operated embedded systems are taking the height of the evolution. This means more dependence on integration of data from various channels, actuators, and sensors — the faculty to operate all the new uses cases such as automatic emergency response systems are functionality requiring more SoC embedded system requirements.

What is happening now?

People. Process. Governance. Adoption. Let’s look at the similarities stemmed from change. We are going to witness new safety laws and revised regulations coming through the industry. These new laws will dictate the demand for connectivity. Indeed, drawing importance this 2015 year with the requirement set by 2018, European Parliament voted in favor of eCall regulation. Cars in Europe must be equipped with eCall, a system that automatically contacts emergency services directing them to the vehicle location in the event of an emergency. The automotive and mobile industries have different regional and market objectives. Together, all the participants in both market segments will need to find ways to collaborate in order to satisfy consumer connectivity needs. Case in point, Chrysler has partnered with Nextel to successfully connect cars like their Dodge Viper, while General Motors uses AT&T as its mobile development partner.

What is resonating from the sales floor and customer perspective?

The demand is increasing for more sophistication and integration of software in the cabin of cars. This is happening from the manufacturer to the supplier network then to the integration partners — all are becoming more engaged to achieve the single outcome, pacing toward the movement to the connected car. Stretched as far as the actual retail outlets, auto dealers are shifting their practice to be more tech savvy, too. The advent of the smart vehicle has already dramatically changed the dealership model, while more transformation awaits the consumer.

On the sales floor as well as the on-boarding experience, sales reps must plan to spend an hour or more teaching customers how to use their car’s advanced technology. But still, these are only a few mentioned scenarios where things have changed in relation to cars and how they are sold and even to the point of how they are distributed, owned, and serviced. One thing for certain, though, is that the design and user trend are intersecting to help shape the demand and experience a driver wants in the connected car. This is further bolstered by the fast paced evolution of smartphones and the marketing experiences now brought forth by the rapid adoption and prolific expansion of the mobile industry tethered by their very seamless and highly evolved experiences drawn from their preferred apps.

Today, customer experiences are becoming more tailored while users, albeit on the screen or engaged with their mobile devices are getting highly acquainted with the expectation of “picking up from where I left off” regardless of what channel, medium, device, or platform. Seamless experiences are breaking through the market. We witness Uber, where users initialize their click on their smartphone then follows by telemetry promoted from Uber drivers and back to the users smart phone. In fact, this happens vis versa, Uber driver’s have information on their console showing customer location and order of priority. Real life interactions are being further enhanced by real-time data, connecting one device to draw forth another platform to continue the journey. Transportation is one of the areas where we can see real-time solutions changing our day-to-day engagement. Some of these are being brought forth by Atmel’s IoT cloud partners such as PubNub where they leverage their stack in devices to offer dispatch, vehicle state, and geo fencing for many vehicle platforms. Companies like Lixar, LoadSmart, GetTaxi, Sidecar, Uber, Lyft are using real-time technologies as integral workings to their integrated vehicle platforms.

Cars are becoming more of a software platform where value chain add-ons tied to an ecosystem are enabled within the software tethered by the cloud where data will continue to enhance the experience. The design trajectory for connected cars follow this software integration arrow. Today, the demand emphasizes mobility along with required connectivity to customer services and advanced functions like power management for electric vehicles, where firmware/software updates further produce refined outcomes in the driver experience (range of car, battery management, other driver assisted functionalities).

Carmakers and mobile operators are debating the best way to connect the car to the web. Built-in options could provide stronger connections, but some consumers prefer tethering their existing smartphone to the car via Bluetooth or USB cable so they can have full access to their personal contacts and playlists. Connected car services will eventually make its way to the broader car market where embedded connections and embedded systems supporting these connections will begin to leverage various needs to integrate traditional desperate signals into a more centrally managed console.

Proliferation of the stack

The arrow of design for connected cars will demand more development, bolstering the concept that software and embedded systems factored with newly-introduced actuators and sensors will become more prevalent. We’re talking about “software on wheels,” “SoC on wheels,” and “secured mobility.”

Design wise, the cost-effective trend will still remain with performance embedded systems. Many new cars may have extremely broad range of sensor and actuator‑based IoT designs which can be implemented on a single compact certified wireless module.

Similarly, having fastest startup times by performing the task with a high-performance MCU vs MPU, is economic for a designer. It can not only reduce significant bill of materials cost, development resources, sculpted form factor, custom wireless design capabilities, but also minimize the board footprint. Aside from that, ARM has various IoT device development options, offering partner ecosystems with modules that have open standards. This ensures ease of IoT or connected car connectivity by having type approval certification through restrictive access to the communications stacks.

Drivers will be prompted with new end user applications — demand more deterministic code and processing with chips that support the secure memory capacity to build and house the software stack in these connected car applications.

Feature upon feature, layer upon layer of software combined with characteristics drawn from the events committed by drivers, tires, wheels, steering, location, telemetry, etc. Adapted speed and braking technologies are emerging now into various connected car makes, taking the traditional ABS concept to even higher levels combined with intelligence, along with controlled steering and better GPS systems, which will soon enable interim or cruise hands-free driving and parking.

Longer term, the technological advances behind the connected car will eventually lead to self-driving vehicles, but that very disruptive concept is still far out.

Where lies innovation and change is disruption

Like every eventual market disruption, there will be the in-between development of this connected car evolution. Innovative apps are everywhere, especially the paradigm where consumers have adopted to the seamless transitional experiences offered by apps and smartphones. Our need for ubiquitous connectivity and mobility, no matter where we are physically, is changing our vehicles into mobile platforms that want us users to seamlessly be connected to the world. This said demand for connectivity increases with the cost and devices involved will become more available. Cars as well as other mobility platforms are increasingly becoming connected packages with intelligent embedded systems. Cars are offering more than just entertainment — beyond providing richer multimedia features and in-car Internet access. Further integration of secure and trusted vital data and connectivity points (hardware security/processing, crypto memory, and crypto authentication) can enable innovative navigation, safety and predictive maintenance capabilities.

Carmakers are worried about recent hacks, especially with issues of security and reliability, making it unlikely that they will be open to every kind of app. They’ll want to maintain some manufactured control framework and secure intrusion thwarting with developers, while also limiting the number of apps available in the car managing what goes or conflicts with the experience and safety measures. Importantly, we are taking notice even now. Disruption comes fast, and Apple and others have been mentioned to enter this connected car market. This is the new frontier for technological equity scaling and technology brand appeal. Much like what we seen in the earlier models of Blackberry to smartphones, those late in the developmental evolution of their platforms may be forced adrift or implode by the market.

No one is arguing it will happen. Eventually, self-driving cars will arrive. But for now, it remains a futuristic concept.

What can we do now in the invention, design and development process?

The broader output of manufactured cars will need to continue in leveraging new designs that take in more integration of traditional siloed integration vendors so that the emergence of more unified and centrally managed embedded controls can make its way. Hence, the importance now exists in the DNA of a holistically designed platform fitted with portfolio of processors and security to take on new service models and applications.

This year, we have compiled an interesting mixture of technical articles to support the development and engineering of car access systems, CAN and LIN networks, Ethernet in the car, capacitive interfaces and capacitive proximity measurement.

In parallel to the support of helping map toward the progress and evolution of the connected car, a new era of design exists. One in which the platform demands embedded controls to evenly match their design characteristics and application use cases. We want to also highlight the highest performing ARM Cortex-M7 based MCU in the market, combining exceptional memory and connectivity options for leading design flexibility. The Atmel | SMART ARM Cortex-M7 family is ideal for automotive, IoT and industrial connectivity markets. These SAM V/E/S family of microcontrollers are the industry’s highest performing Cortex-M microcontrollers enhancing performance, while keeping cost and power consumption in check.

So are you designing for the latest automotive, IoT, or industrial product? Here’s a few things to keep in mind:

Optimized for real-time deterministic code execution and low latency peripheral data access
Six-stage dual-issue pipeline delivering 1500 CoreMarks at 300MHz
Automotive-qualified ARM Cortex-M7 MCUs with Audio Video Bridging (AVB) over Ethernet and Media LB peripheral support (only device in the market today)
M7 provides 32-bit floating point DSP capability as well as faster execution times with greater clock speed, floating point and twice the DSP power of the M4

We are taking the connected car design to the next performance level — having high-speed connectivity, high-density on-chip memory, and a solid ecosystem of design engineering tools. Recently, Atmel’s Timothy Grai added a unveiling point to the DSP story in Cortex-M7 processor fabric. True DSPs don’t do control and logical functions well; they generally lack the breadth of peripherals available on MCUs. “The attraction of the M7 is that it does both — DSP functions and control functions — hence it can be classified as a digital signal controller (DSC).” Grai quoted the example of Atmel’s SAM V70 and SAM V71 microcontrollers are used to connect end-nodes like infotainment audio amplifiers to the emerging Ethernet AVB network. In an audio amplifier, you receive a specific audio format that has to be converted, filtered, and modulated to match the requirement for each specific speaker in the car. Ethernet and DSP capabilities are required at the same time.

“The the audio amplifier in infotainment applications is a good example of DSC; a mix of MCU capabilities and peripherals plus DSP capability for audio processing. Most of the time, the main processor does not integrate Ethernet AVB, as the infotainment connectivity is based on Ethernet standard,” Grai said. “Large SoCs, which usually don’t have Ethernet interface, have slow start-up time and high power requirements. Atmel’s SAM V7x MCUs allow fast network start-up and facilitate power moding.”

Atmel has innovative memory technology in its DNA — critical to help fuel connected car and IoT product designers. It allows them to run the multiple communication stacks for applications using the same MCU without adding external memory. Avoiding external memories reduces the PCB footprint, lowers the BOM cost and eliminates the complexity of high-speed PCB design when pushing the performance to a maximum.

Importantly, the Atmel | SMART ARM Cortex-M7 family achieves a 1500 CoreMark Score, delivering superior connectivity options and unique memory architecture that can accommodate the said evolve of the eventual “SoC on wheels” design path for the connected car.

How to get started

Download this white paper detailing how to run more complex algorithms at higher speeds.
Check out the Atmel Automotive Compilation.
Attend hands-on training onboard the Atmel Tech on Tour trailer. Following these sessions, you will walk away with the Atmel | SMART SAM V71 Xplained Ultra Evaluation Kit.
Design the newest wave of embedded systems using SAM E70, SAM S70, or SAM V70 (ideal for automotive, IoT, smart gateways, industrial automation and drone applications, while the auto-grade SAM V70 and SAM V71 are ideal for telematics, audio amplifiers and advanced media connectivity).

[Images: European Commission, GSMA]

How to prevent execution surprises for Cortex-M7 MCU

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We know the heavy weight linked with software development, in the 60% to 70% of the overall project cost.

The ARM Cortex-A series processor core (A57, A53) is well known in the high performance market segments, like application processing for smartphone, set-top-box and networking. If you look at the electronic market, you realize that multiple applications are cost sensitive and don’t need such high performance processor core. We may call it the embedded market, even if this definition is vague. The ARM Cortex-M family has been developed to address these numerous market segments, starting with the Cortex-M0 for lowest cost, the Cortex-M3 for best power/performance balance, and the Cortex-M4 for applications requiring digital signal processing (DSP) capabilities.

For the audio, voice control, object recognition, and complex sensor fusion of automotive and higher-end Internet of Things sensing, where complex algorithms for audio and video are needed for rich audio and visual capabilities, Cortex-M7 is required. ARM offers the processor core as well as the Tightly Coupled Memory (TCM) architecture, but ARM licensees like Atmel have to implement memories in such a way that the user can take full benefit from the M7 core to meet system performance and latency goals.

The TCM interface provides a single 64-bit instruction port and two 32-bit data ports.

In a 65nm embedded Flash process device, the Cortex-M7 can achieve a 1500 CoreMark score while running at 300 MHz, offering top class DSP performance: double-precision floating-point unit and a double-issue instruction pipeline. But algorithms like FIR, FFT or Biquad need to run as deterministically as possible for real-time response or seamless audio and video performance. How do you best select and implement the memories needed to support such performance? If you choose Flash, this will require caching (as Flash is too slow) leading to cache miss risk. Whereas SRAM technology is a better choice since it can be easily embedded on-chip and permits random access at the speed of processor.

Peripheral data buffers implemented in general-purpose system SRAM are typically loaded by DMA transfers from system peripherals. The ability to load from a number of possible sources, however, raises the possibility of unnecessary delays and conflicts by multiple DMAs trying to access the memory at the same time. In a typical example, we might have three different entities vying for DMA access to the SRAM: the processor (64-bit access, requesting 128 bits for this example) and two separate peripheral DMA requests (DMA0 and DMA1, 32-bit access each). Atmel has get round this issue by organizing the SRAM into several banks as described in this picture:

By organizing the SRAM into banks, multiple DMA bursts can occur simultaneously with minimal latency.

For a chip maker designing microcontrollers, licensing ARM Cortex-M processor core provides numerous advantages. The very first is the ubiquity of the ARM core architecture, being adopted in multiple market segments to support variety of applications. If this chip maker wants to design-in a new customer, the probability that such OEM has already used ARM-based MCU is very high, and it’s very important for this OEM to be able to reuse existing code (we know the heavy weight linked with software development, in the 60% to 70% of the overall project cost). But this ubiquity generates a challenge: how do you differentiate from the competition when competitors can license exactly the same processor core?

Selecting a more aggressive technology node and providing better performance at lower cost are an option, but we understand that this advantage can disappear as soon as the competition also move to this node. Integrating larger amount of Flash is another option, which is very efficient if the product is designed on a technology that enables it to keep the pricing low enough.

If the chip maker has designed on an aggressive technology node for higher performance and offers a larger amount of Flash than the competition, it may be enough differentiation. Completing with the design of a smarter memory architecture unencumbered by cache misses, interrupts, context swaps, and other execution surprises that work against deterministic timing allow bringing strong differentiation.

If you want to more completely understand how Atmel has designed this SMART memory architecture for the Cortex-M7, I encourage you to read this white paper from Jacko Wilbrink and Lionel Perdigon entitled “Run Blazingly Fast Algorithms with Cortex-M7 Tightly Coupled Memories.” (You will have to register.) This paper describes MCUs integrating SRAM organized into four banks that can be used as general SRAM and for TCM, showing one example of a Cortex-M7 MCU being implemented in the Atmel | SMART SAM S70, SAM E70 and SAM V70/V71 families.

This post has been republished with permission from SemiWiki.com, where Eric Esteve is a principle blogger, as well as one of the four founding members of the site. This blog was originally shared on August 6, 2015.

4 designs tips for AVB in-car infotainment

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AVB is clearly the choice of several automotive OEMs, says Gordon Bechtel, CTO, Media Systems, Harman Connected Services.

Audio Video Bridging (AVB) is a well-established standard for in-car infotainment, and there is a significant amount of activity for specifying and developing AVB solutions in automobiles. The primary use case for AVB is interconnecting all devices in a vehicle’s infotainment system. That includes the head unit, rear-seat entertainment systems, telematics unit, amplifier, central audio processor, as well as rear-, side- and front-view cameras.

The fact that these units are all interconnected with a common, standards-based technology that is certified by an independent market group — AVnu — is a brand new step for the automotive OEMs. The AVnu Alliance facilitates a certified networking ecosystem for AVB products built into the Ethernet networking standard.

According to Gordon Bechtel, CTO, Media Systems, Harman Connected Services, AVB is clearly the choice of several automotive OEMs. His group at Harman develops core AVB stacks that can be ported into car infotainment products. Bechtel says that AVB is a big area of focus for Harman.

AVB Design Considerations

Harman Connected Services uses Atmel’s SAM V71 microcontrollers as communications co-processors to work on the same circuit board with larger Linux-based application processors. The software firm writes codes for customized reference platforms that automotive OEMs need to go beyond the common reference platforms.

Based on his experience of automotive infotainment systems, Bechtel has outlined the following AVB design dos and don’ts for the automotive products:

1. Sub-microsecond accuracy: Every AVB element on the network is hooked to the same accurate clock. The Ethernet hardware should feature a time stand to ensure packet arrival in the right order. Here, Bechtel mentioned the Atmel | SMART SAM V71 MCU that boasts screen registers to ensure advanced hardware filtering of inbound packets for routing to correct receive-end queues.

2. Low latency: There is a lot of data involved in AVB, both in terms of bit rate and packet rate. AVB allows low latency through reservations for traffic, which in turn, facilitate faster packet transfer for higher priority data. Design engineers should carefully shape the data to avoid packet bottlenecks as well as data overflow.

Bechtel once more pointed to Atmel’s SAM V71 microcontrollers that provide two priority queues with credit-based shaper (CBS) support that allows the hardware-based traffic shaping compliant with 802.1Qav (FQTSS) specifications for AVB.

3. 1588 Timestamp unit: It’s a protocol for correct and accurate 802.1 AS (gPTP) support as required by AVB for precision clock synchronization. The IEEE 802.1 AS carries out time synchronization and is synonymous with generalized Precision Time Protocol or gPTP.

Timestamp compare unit and a large number of precision timer counters are key for the synchronization needed in AVB for listener presentations times and talker transmissions rates as well as for media clock recovery.

4) Tightly coupled memory (TCM): It’s a configurable high-performance memory access system to allow zero-wait CPU access to data and instruction memory blocks. A careful use of TCM enables much more efficient data transfer, which is especially important for AVB class A streams.

It’s worth noting that MCUs based on ARM Cortex-M7 architecture have added the TCM capability for fast and deterministic code execution. TCM is a key enabler in running audio and video streams in a controlled and timely manner.

AVB and Cortex-M7 MCUs

The Cortex-M7 is a high-performance core with almost double the power efficiency of the older Cortex-M4. It features a six-stage superscalar pipeline with branch prediction — while the M4 has a three-stage pipeline. Bechtel of Harman acknowledged that M7 features equate to more highly optimized code execution, which is important for Class A audio implementations with lower power consumption.

Again, Bechtel referred to the SAM V71 MCUs — which are based on the Cortex-M7 architecture — as particularly well suited for the smaller ECUs. “Rear-view cameras and power amplifiers are good examples where the V71 microcontroller would be a good fit,” he said. “Moreover, the V71 MCUs can meet the quick startup requirements needed by automotive OEMs.”

Figure 3 - Atmel's V71 is an M7 chip for Ethernet AVB networking and audio processing

The infotainment connectivity is based on Ethernet, and most of the time, the main processor does not integrate Ethernet AVB. So the M7 microcontrollers, like the V71, bring this feature to the main processor. For the head unit, it drives the face plate, and for the telematics control, it contains the modem to make calls so echo cancellation is a must, for which DSP capability is required.

Take the audio amplifier, for instance, which receives a specific audio format that has to be converted, filtered and modulated to match the requirement for each specific speaker in the car. This means infotainment system designers will need both Ethernet and DSP capability at the same time, which Cortex-M7 based chips like V71 provide at low power and low cost.

6 memory considerations for Cortex-M7-based IoT designs

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Taking a closer look at the configurable memory aspects of Cortex-M7 microcontrollers.

Tightly coupled memory (TCM) is a salient feature in the Cortex-M7 lineup as it boosts the MCU’s performance by offering single cycle access for the CPU and by securing the high-priority latency-critical requests from the peripherals.

The early MCU implementations based on the ARM’s M7 embedded processor core — like Atmel’s SAM E70 and S70 chips — have arrived in the market. So it’d be worthwhile to have a closer look at the configurable memory aspects of M7 microcontrollers and see how the TCMs enable the execution of deterministic code and fast transfer of real-time data at the full processor speed.

Here are some of the key findings regarding the advanced memory architecture of Cortex-M7 microcontrollers:

1. TCM is Configurable

First and foremost, the size of TCM is configurable. TCM, which is part of the physical memory map of the MCU, supports up to 16MB of tightly coupled memory. The configurability of the ARM Cortex-M7 core allows SoC architects to integrate a range of cache sizes. So that industrial and Internet of Things product developers can determine the amount of critical code and real-time data in TCM to meet the needs of the target application.

The Atmel | SMART Cortex-M7 architecture doesn’t specify what type of memory or how much memory should be provided; instead, it leaves these decisions to designers implementing M7 in a microcontroller as a venue for differentiation. Consequently, a flexible memory system can be optimized for performance, determinism and low latency, and thus can be tuned to specific application requirements.

2. Instruction TCM

Instruction TCM or ITCM implements critical code with deterministic execution for real-time processing applications such as audio encoding/decoding, audio processing and motor control. The use of standard memory will lead to delays due to cache misses and interrupts, and therefore will hamper the deterministic timing required for real-time response and seamless audio and video performance.

The deterministic critical software routines should be loaded in a 64-bit instruction memory port (ITCM) that supports dual-issue processor architecture and provide single-cycle access for the CPU to boost MCU performance. However, developers need to carefully calibrate the amount of code that need zero-wait execution performance to determine the amount of ITCM required in an MCU device.

The anatomy of TCM inside the M7 architecture.

3. Data TCM

Data TCM or DTCM is used in fast data processing tasks like 2D bar decoding and fingerprint and voice recognition. There are two data ports (DTCMs) that provide simultaneous and parallel 32-bit data accesses to real-time data. Both instruction TCM and data TCM — used for efficient access to on-chip Flash and external resources — must have the same size.

4. System RAM and TCM

System RAM, also known as general RAM, is employed for communications stacks related to networking, field buss, high-bandwidth bridging, USB, etc. It implements peripheral data buffers generally through direct memory access (DMA) engines and can be accessed by masters without CPU intervention.

Here, product developers must remember the memory access conflicts that arise from the concurrent data transfer to both CPU and DMA. So developers must set clear priorities for latency-critical requests from the peripherals and carefully plan latency-critical data transfers like the transfer of a USB descriptor or a slow data rate peripheral with a small local buffer. Access from the DMA and the caches are generally burst to consecutive addresses to optimize system performance.

It’s worth noting that while system memory is logically separate from the TCM, microcontroller suppliers like Atmel are incorporating TCM and system RAM in a single SRAM block. That lets IoT developers share general-purpose tasks while splitting TCM and system RAM functions for specific use cases.

A single SRAM block for TCM and system memory allows higher flexibility and utilization.

5. TCM Loading

The Cortex-M7 uses a scattered RAM architecture to allow the MCU to maximize performance by having a dedicated RAM part for critical tasks and data transfer. The TCM might be loaded from a number of sources, and these sources aren’t specified in the M7 architecture. It’s left to the MCU designers whether there is a single DMA or several data loading points from various streams like USB and video.

It’s imperative that, during the software build, IoT product developers identify which code segments and data blocks are allocated to the TCM. This is done by embedding programs into the software and by applying linker settings so that software build appropriately places the code in memory allocation.

6. Why SRAM?

Flash memory can be attached to a TCM interface, but the Flash cannot run at the processor clock speed and will require caching. As a result, this will cause delays when cache misses occur, threatening the deterministic value proposition of the TCM technology.

DRAM technology is a theoretical choice but it’s cost prohibitive. That leaves SRAM as a viable candidate for fast, direct and uncached TCM access. SRAM can be easily embedded on a chip and permits random accesses at the speed of the processor. However, cost-per-bit of SRAM is higher than Flash and DRAM, which means it’s critical to keep the size of the TCM limited.

Atmel | SMART Cortex-M7 MCUs

Take the case of Atmel’s SMART SAM E70, S70 and V70/71 microcontrollers that organize SRAM into four memory banks for TCM and System SRAM parts. The company has recently started shipping volume units of its SAM E70 and S70 families for the IoT and industrial markets, and claims that these MCUs provide 50 percent better performance than the closest competitor.

Atmel’s M7-based microcontrollers offer up to 384KB of embedded SRAM that is configurable as TCM or system memory for providing IoT designs with higher flexibility and utilization. For instance, E70 and S70 microcontrollers organize 384KB of embedded SRAM into four ports to limit memory access conflicts. These MCUs allocate 256KB of SRAM for TCM functions — 128 KB for ITCM and DTCM each — to deliver zero wait access at 300MHz processor speed, while the remaining 128KB of SRAM can be configured as system memory running at 150MHz.

However, the availability of an SRAM block organized in the form of a memory bank of 384KB means that both system SRAM and TCM can be used at the same time.The large on-chip SRAM of 384KB is also critical for many IoT devices, since it enables them to run multiple communication stacks and applications on the same MCU without adding external memory. That’s a significant value proposition in the IoT realm because avoiding external memories lowers the BOM cost, reduces the PCB footprint and eliminates the complexity in the high-speed PCB design.

Majeed Ahmad is the author of books Smartphone: Mobile Revolution at the Crossroads of Communications, Computing and Consumer Electronics and The Next Web of 50 Billion Devices: Mobile Internet’s Past, Present and Future.

Why do drones love the Atmel SAM E70?

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Eric Esteve explains why the latest Cortex-M7 MCU series will open up countless capabilities for drones other than just flying.

By nature, avionics is a mature market requiring the use of validated system solution: safety is an absolute requirement, while innovative systems require a stringent qualification phase. That’s why the very fast adoption of drones as an alternative solution for human piloted planes is impressive. It took 10 or so years for drones to become widely developed and employed for various applications, ranging from war to entertainment, with prices spanning a hundreds of dollars to several hundreds of thousands. But, even if we consider consumer-oriented, inexpensive drones, the required processing capabilities not only call for high performance but versatile MCU as well, capable of managing its built-in gyroscope, accelerator, geomagnetic sensor, GPS, rotational station, four to six-axis control, optical flow and so on.

When I was designing for avionics, namely the electronic CFM56 motor control (this reactor being jointly developed by GE in the U.S. and Snecma in France, equipping Boeing and Airbus planes), the CPU was a multi-hundred dollar Motorola 68020, leading to a $20 per MIPS cost! While I may not know the Atmel | SMART SAM E70 price precisely — I would guess that it cost a few dollars — what I do I know is that the MCU is offering an excess of 600 DMIPS. Aside from its high performance, this series boasts a rather large on-chip memory size of up to 384KB SRAM and 2MB Flash — just one of many pivotal reasons that this MCU has been selected to support the “drone with integrated navigation control to avoid obstacle and improve stability.”

In fact, the key design requirements for this application were: +600 DMIPS, camera sensor interface, dual ADC and PWM for motor control and dual CAN, all bundled up in a small package. Looking at the block diagram below helps link the MCU features with the various application capabilities: gyroscope (SPI), accelerator (SPI x2), geomagnetic sensor (I2C x2), GPS (UART), one or two-channel rotational station (UART x2), four or six-axis control communication (CAN x2), voltage/current (ADC), analog sensor (ADC), optical flow sensor (through image sensor Interface or ISI) and pulse width modulation (PWM x8) to support the rotational station and four or six-axis speed PWM control.

For those of you who may not know, the SAM E70 is based on the ARM-Cortex M7 — a principle and multi-verse handling MCU that combines superior performance with extensive peripheral sets supporting multi-threaded processes. It’s this multi-thread support that will surely open up countless capabilities for drones other than simply flying.

Today’s drones already possess the ability to soar through the air or stay stationary, snapping pictures or capturing HD footage. That’s already very impressive to see sub-kilogram devices offering such capabilities! However, the drone market is already looking ahead, preparing for the future, with the desire to get more application stacks into the UAVs so they can take in automation, routing, cloud connectivity (when available), 4G/5G, and other wireless functionalities to enhance data pulling and posting.

For instance, imagine a small town tallying a few thousand habitants, except a couple of days or weeks per year because of a special event or holiday, a hundred thousand people come storming into the area. These folks want to feed their smartphone with multimedia or share live experiences by sending movies or photos, most of them at the same time. The 4G/5G and cloud infrastructure is not tailored for such an amount of people, so the communication system may break. Yet, this problem could be fixed by simply calling in drone backup to reinforce the communication infrastructure for that period of time.

While this may be just one example of what could be achieved with the advanced usage of drones, each of the innovative applications will be characterized by a common set of requirements: high processing performance, large SRAM and flash memory capability, and extensive peripheral sets supporting multi-threaded processes. In this case, the Cortex M7 ARM-based SAM E70 MCU is an ideal choice with processing power in excess of 640 DMIPS, large on-chip SRAM (up to 384 KB) and Flash (up to 2MB) capabilities managing all sorts of sensors, navigation, automation, servos, motor, routing, adjustments, video/audio and more.

Intrigued? You’ll want to check out some of the products and design kits below:

This post has been republished with permission from SemiWiki.com, where Eric Esteve is a principle blogger as well as one of the four founding members of SemiWiki.com. This blog first appeared on SemiWiki on July 18, 2015.

3 design hooks of Atmel MCUs for connected cars

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The MPU and MCU worlds are constantly converging and colliding, and the difference between them is not a mere on-off switch — it’s more of a sliding bar.

In February 2015, BMW reported that it patched the security flaw which could allow hackers to remotely unlock the doors of more than 2 million BMW, Mini and Rolls-Royce vehicles. Earlier, researchers at ADAC, a German motorist association, had demonstrated how they could intercept communications with BMW’s ConnectedDrive telematics service and unlock the doors.

BMW uses SIM card installed in the car to connect to a smartphone app over the Internet. Here, the ADAC researchers created a fake mobile network and tricked nearby cars into taking commands by reverse engineering the BMW’s telematics software.

The BMW hacking episode was a rude awakening for the connected car movement. The fact that prominent features like advanced driver assistance systems (ADAS) are all about safety and security is also a testament is that secure connectivity will be a prime consideration for the Internet of Cars.

Built-in Security

Atmel is confident that it can establish secure connections for the vehicles by merging its security expertise with performance and low-power gains of ARM Cortex-M7 microcontrollers. The San Jose, California-based chip supplier claims to have launched the industry’s first auto-qualified M7-based MCUs with Ethernet AVB and media LB peripherals. In addition, this high-end MCU series for in-vehicle infotainment offers the CAN 2.0 and CAN flexible data rate controller for higher bandwidth requirements.

Nicolas Schieli, Automotive MCU Marketing Director at Atmel, acknowledges that security is something new in the automotive environment that needs to be tackled as cars become more connected. “Anything can connect to the controller area network (CAN) data links.”

Schieli notes that the Cotex-M7 has embedded enhanced security features within its architecture and scalability. On top of that, Atmel is using its years of expertise in Trusted Platform Modules and crypto memories to securely connect cars to the Internet, not to mention the on-chip SHA and AES crypto engines in SAM E70/V70/V71 microcontrollers for encryption of data streams. “These built-in security features accelerate authentication of both firmware and applications.”

He explained how the access to the Flash, SRAM, core registers and internal peripherals is blocked to enable security. It’s done either through the SW-DP/JTAG-DP interface or the Fast Flash Programming Interface. The automotive-qualified SAM V70 and V71 microcontrollers support Ethernet AVB and Media LB standards, and they are targeted for in-vehicle infotainment connectivity, audio amplifiers, telematics and head control units companion devices.

Software Support

The second major advantage that Atmel boasts in the connected car environment is software expertise and an ecosystem to support infotainment applications. For instance, a complete automotive Ethernet Audio Video Bridging (AVB) stack is being ported to the SAM V71 microcontrollers.

Software support is a key leverage in highly fragmented markets like automotive electronics. Atmel’s software package encompasses peripheral drivers, open-source middleware and real-time operating system (RTOS) features. The middleware features include USB class drivers, Ethernet stacks, storage file systems and JPEG encoder and decoder.

Next, the company offers support for several RTOS platforms like RTX, embOS, Thread-X, FreeRTOS and NuttX. Atmel also facilitates the software porting of any proprietary or commercial RTOS and middleware. Moreover, the MCU supplier from San Jose features support for specific automotive software such as AUTOSAR and Ethernet AVB stacks.

Atmel supports IDEs such as IAR or ARM MDK and Atmel Studio and it provides a full-featured board that covers all MCU series, including E70, V70 and V71 devices. And, a single board can cover all Atmel microcontrollers. Moreover, the MCU supplier provides Board Support Package for Xplained evaluation kit and easy porting to customer boards through board definition file (board.h).

Beyond that, Atmel is packing more functionality and software features into its M7 microcontrollers. Take SAM V71 devices, for example, which have three software-selectable low-power modes: sleep, wait and backup. In sleep mode, the processor is stopped while all other functions can be kept running. While in wait mode, all clocks and functions are stopped but some peripherals can be configured to wake up the system based on predefined conditions. In backup mode, RTT, RTC and wake-up logic are running. Furthermore, the microcontroller can meet the most stringent key-off requirements while retaining 1Kbyte of SRAM and wake-up on CAN.

Transition from MPU to MCU

Cortex-M7 is pushing the microcontroller performance in the realm of microprocessors. MPUs, which boast memory management unit and can run operating systems like Linux, eventually lead to higher memory costs. “Automakers and systems integrators are increasingly challenged in getting performance point breakthrough because they are running out of Flash capacity,” explained Schieli.

On the other hand, automotive OEMs are trying to squeeze costs in order to bring the connected car riches to non-luxury vehicles, and here M7 microcontrollers can help bring down costs and improve the simplification of car connectivity.

The M7 microcontrollers enable automotive embedded systems without the requirement of a Linux head and can target applications with high performance while running RTOS or bare metal implementation. In other words, M7 opens up avenues for automotive OEMs if they want to make a transition from MPU to MCU for cost benefits.

However, the MPU and MCU worlds are constantly converging and colliding, and the difference between them is not a mere on-off switch. It’s more of a sliding bar. Atmel, having worked on both sides of the fence, can help hardware developers to manage that sliding bar well. “Atmel is using M7 architecture to help bridge the gap between microprocessors and high-end MCUs,” Schieli concludes.

Atmel tightens automotive focus with new Cortex-M7 MCUs

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Large SoCs without an Ethernet interface typically have slow start-up times and high-power requirements — until now.

Atmel, a lead partner for the ARM Cortex-M7 processor launch in October 2014, has unveiled three new M7-based microcontrollers with a unique memory architecture and advanced connectivity features for the connected car market.

According to a company spokesman, E70, V71 and V70 chips are the industry’s highest performing Cortex-M microcontrollers with six-stage dual-issue pipeline delivering 1500 CoreMarks at 300MHz. Moreover, V70 and V71 microcontrollers are the only automotive-qualified ARM Cortex-M7 MCUs with Audio Video Bridging (AVB) over Ethernet and Media LB peripheral support.

Atmel is among the first suppliers to introduce the ARM Cortex-M7-based MCUs, whose core combines performance and simplicity and further pushes the performance envelope for embedded devices. The new MCU devices are aimed to take the connected car design to the next performance level with high-speed connectivity, high-density on-chip memory, and a solid ecosystem of design engineering tools.

Atmel’s Memory Play

Atmel has memory technology in its DNA, and that seems apparent in the design footprint of E70, V70 and V71 MCUs. The San Jose-based chipmaker is offering a flexible memory system that is optimized for performance, determinism and low latency.

Jacko Wilbrink, Senior Marketing Director at Atmel, said that the company’s Cortex-M7-based MCUs leverage Atmel’s advanced peripherals and flexible SRAM architecture for higher performance applications while keeping the Cortex-M class ease-of-use. He added that the large on-chip SRAM on SAM E70/V70/V71 chips is critical for connected car and IoT product designers since it allows them to run the multiple communication stacks and applications on the same MCU without adding external memory.

On-chip DMA and low-latency access SRAM architecture

Avoiding the external memories reduces the PCB footprint, lowers the BOM cost and eliminates the complexity of high-speed PCB design when pushing the performance to a maximum. Next, Tim Grai, another senior manager at Atmel, pointed out another critical take from Cortex-M7 designs: The tightly coupled memory (TCM) interface. It provides the low-latency memory that the processor can use without the unpredictability that is a feature of cache memories.

Grai says that the most vital memory feature is not the memory itself but how the TCM interface to the M7 is utilized. “The available RAM is configurable to be used as system RAM or tightly-coupled instruction and data memory to the core, where it provides deterministic zero-wait state access,” Grai added. “The arrangement of SRAM allows for multiple concurrent accesses.”

Cortex-M7 a DSP Winner

According to Will Strauss, President & Principal Analyst at Forward Concepts, ARM has had considerable success with its Cortex-M4 power-efficient 32-bit processor chip family. “However, realizing that it lacked the math ability to do more sophisticated DSP functions, ARM has introduced the Cortex-M7, its newest and most powerful member of the Cortex-M family.”

Strauss adds that the M7 provides 32-bit floating point DSP capability as well as faster execution times. With the greater clock speed, floating point and twice the DSP power of the M4, the M7 is even more attractive for applications requiring high-performance audio and even video accompanying traditional automotive and control applications.

Atmel’s Grai added an interesting dimension to the DSP story in Cortex-M7 processor fabric. He pointed out that true DSPs don’t do control and logical functions well and generally lack the breadth of peripherals available on MCUs. “The attraction of the M7 is that it does both—DSP functions and control functions—hence it can be classified as a digital signal controller (DSC).”

Grai quoted the example of Atmel V70 and V71 microcontrollers used to connect end-nodes like infotainment audio amplifiers to the emerging Ethernet AVB network. In an audio amplifier, you receive a specific audio format that has to be converted, filtered, modulated to match the requirement for each specific speaker in the car. So you need Ethernet and DSP capabilities at the same time.

Grai says that the audio amplifier in infotainment applications is a good example of DSC: a mix of MCU capabilities and peripherals plus DSP capability for audio processing. Atmel is targeting the V70 and V71 chips as a bridge between large application processors and Ethernet.

Most of the time, the main processor does not integrate Ethernet AVB, as the infotainment connectivity is based on Ethernet standard. Here, the V71 microcontroller brings this feature to the main processor. “Large SoCs, which usually don’t have Ethernet interface, have slow start-up time and high power requirements,” Grai said. “Atmel’s V7x MCUs allow fast network start-up and facilitate power moding.”

The SAM E70, V70 and V71

Atmel’s three new MCU devices are aimed at multiple aspects of in-vehicle infotainment connectivity and telematics control.

SAM E70: The microcontroller series features Dual CAN-FD, 10/100 Ethernet MAC with IEEE1588 real-time stamping, and AVB support. It’s aimed at automotive industry’s movement toward controller area network (CAN) message-based protocols holistically across the cabin, eliminating isolation and wire redundancy, and have them all bridged centrally with the CAN interface.

SAM V70: It’s designed for MediaLB connectivity and leverages advanced audio processing, multi-port memory architecture and Cortex-M7 DSP capabilities. For the media-oriented systems transport (MOST) architecture, old modules are not redesigned. So Atmel offers a MOST solution that is done over Media Local Bus (MediaLB) and is supported by the V70 series.

SAM V71: The MCU series ports a complete automotive Ethernet AVB stack for in-vehicle infotainment connectivity, audio amplifiers, telematics and head control units. It mirrors the SAM V70 series features as well as combines Ethernet-AVB and MediaLB connectivity stacks.

What is real SAM V71 DSP performance in automotive audio?

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The integrated FPU DSP (into the Cortex-M7 core) is using 2X the number of clock cycles when compared with the SHARC21489.

Thinking of selecting an ARM Cortex-M7-based Atmel SAM V70/71 for your next automotive entertainment application? Three key reasons to consider are the clock speed of the the Cortex-M7 (300 Mhz), the integration of a floating point (FPU) DSP, and last but not least, because the SAM V70/71 has obtained automotive qualification. If you delve deeper into the SAM V70/71 features list, you will see that this MCU is divided into several versions integrating Flash: 512 KB, 1024 KB or 2018 KB. And, if you compare with the competition, this MCU is the only Cortex-M7 supporting the 2 MB Flash option, being automotive qualified and delivering 1500 CoreMark — thanks to the 300 MHz clock speed when the closest competitor only reach 240 MHz and deliver 1200 CoreMark.

In fact, what makes the SAMV70/71 so unique is its FPU DSP performance. Let’s make it clear for the beginning, if you search for pure DSP performance, it will be easy to find standard DSP chip offering much higher performance. Take the Analog Device AD21489 or Blackfin70x series, for example. However, the automotive market is not only very demanding, it’s also a very cost sensitive market as well.

Think about this simple calculation: If you select AD21489 DSP, you will have to add external flash and a MCU, which would lead the total BOM to be four to five times the price associated with the SAM V71. (Let’s also keep this AD21489 as a reference in terms of performance, and examine DSP benchmark results, coming from third party DSP experts DSP Concept.)

Before analyzing the results, we need to describe the context:

FIR is made on 256 samples block size
Results are expressed in term of clock cycles (smaller is better)
All DSP are floating-point except Blackfin
Clock cycles count is measured using Audio Weaver

To elaborate upon that even further, this FIR is used to build equalization filter — the higher Taps count, the better. If we look at the “50 Taps” benchmark results, the SAM V71 (Cortex-M7 based) exhibits 22,734 clock cycles (about three times more than the SHARC21489). Unsurprisingly, the Cortex-M4 requires 50% more, but you have to integrate a Cortex-A15 to get better results, as both the Cortex-A8 and Cortex-A9 need 30% and 40% more cycles, respectively! And when looking at standard Analog Devices Blackfin DSP, only the 70x series is better by 35%… the 53x being 30% worst.

Now, if you want to build a graphic equalizer, you will have to run Biquad. For instance, when building eight channels and six stages graphic equalizer, your DSP will have to run 48 Biquad.

Again, the context:

Biquad is made on 256 samples block size
Results are expressed in term of clock cycles (smaller is better)
All DSP are floating-point except Blackfin
Clock cycles count is measured using Audio Weaver

In fact, the results are quite similar to those of the FIR benchmark: only the Cortex-A15 and the SHARC21489 exhibits better performance. The integrated FPU DSP (into the Cortex-M7 core) is using twice the amount of clock cycles when put side-by-side with the SHARC21489. If you compare the performance per price, the Cortex-M7 integrated in the SAMV71 is 50% cheaper! Using a SHARC DSP certainly makes sense if you want to build high performance home cinema system, but if you target automotive, it’s much more effective to select a FPU DSP integrated together with Flash (512KB to 2MB) and a full featured MCU.

The Atmel SAM V71 is specifically dedicated to support automotive infotainment application, offering Dual CAN and Ethernet MAC support. Other notable specs include:

10/100 Mbps, IEEE1588 support
12 KB SRAM plus DMA
AVB support with Qav & Qas HW support for audio traffic support
802.3az Energy efficiency support
Dual CAN-FD
Up to 64 SRAM-based mailboxes
Wake up from sleep or wake up modes on RX/TX

Don’t forget that when looking to construct an automotive high-end radio, you still need room for Ethernet MAC and AVB support… What’s more, the SAM V71 only consume 68% of the DSP resource, leaving well enough space for both AVB and Ethernet MAC.

Interested? Explore the Atmel | SMART SAM V ARM Cortex-M7 family here. More information about the the DSP benchmark can be also found on DSP Concept’s website. Also, be sure the detailed DSP Concept’s audio processing benchmarks.

This post has been republished with permission from SemiWiki.com, where Eric Esteve is a principle blogger as well as one of the four founding members of SemiWiki.com. This blog first appeared on SemiWiki on May 6, 2015.

Single chip MCU + DSP architecture for automotive = SAM V71

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Automotive apps are running in production by million units per year, and cost is a crucial factor when deciding on an integrated solution.

It’s all about Cost of Ownership (CoO) and system level integration. If you target automotive related application, like audio or video processing or control of systems (Motor control, inverter, etc.), you need to integrate strong performance capable MCU with a DSP. In fact, if you expect your system to support Audio Video Bridging (AVB) MAC on top of the targeted application and to get the automotive qualification, the ARM Cortex-M7 processor-based Atmel SAMV70/71 should be your selection: offering the fastest clock speed of his kind (300 MHz), integrating a DSP Floating Point Unit (FPU), supporting AVB and qualified for automotive.

Let’s have a closer look at the SAM V71 internal architecture, shall we?

A closer look at Atmel | SMART ARM based Cortex M7 – SAMV71 internal architecture.

When developing a system around a microcontroller unit, you expect this single chip to support as many peripherals as needed in your application to minimize the global cost of ownership. That’s why you can see the long list of system peripherals (top left of the block diagram). Meanwhile, the Atmel | SMART SAM V71 is dedicated to support automotive infotainment application, e.g. Dual CAN and Ethernet MAC (bottom right). If we delve deeper into these functions, we can list these supported features:

10/100 Mbps, IEEE1588 support
MII (144-pin), RMII (64-, 100, 144-pin)
12 KB SRAM plus DMA
AVB support with Qav & Qas HW support for Audio traffic support
802.3az Energy efficiency support
Dual CAN-FD
Up to 64 SRAM-based mailboxes
Wake up from sleep or wake up modes on RX/TX

The automotive-qualified SAM V70 and V71 series also offers high-speed USB with integrated PHY and Media LB, which when combined with the Cortex-M7 DSP extensions, make the family ideal for infotainment connectivity and audio applications. Let’s take a look at this DSP benchmark:

ARM CM7 Performance normalized relative to SHARC (Higher numbers are better).

If you are not limited by budget consideration and can afford integrating one standard DSP along with a MCU, you will probably select the SHARC 21489 DSP (from Analog Devices) offering the best-in-class benchmark results for FIR, Biquad and real FFT. However, such performance has a cost, not only monetarily but also in terms of power consumption and board footprint — we can call that “Cost of Ownership.” Automotive apps are running in production by million units per year, and cost is absolutely crucial in this market segment, especially when quickly deciding to go with an integrated solution.

To support audio or video infotainment application, you expect the DSP integrated in the Cortex-M7 to be “good enough” and you can see from this benchmark results that it’s the case for Biquad for example, as ARM CM7 is equal or better than any other DSP (TI C28, Blackfin 50x or 70x) except the SHARC 21489… but much cheaper! Good enough means that the SAMV70 will support automotive audio (Biquad in this case) and keep enough DSP power for Ethernet MAC (10/100 Mbps, IEEE1588) support.

Ethernet AVB Architectures (SAM V71)

In the picture above, you can see the logical SAM V71 architectures for Ethernet AVB support and how to use the DSP capabilities for Telematics Control Unit (TCU) or audio amplifier.

Integrating a DSP means that you need to develop the related DSP code. Because the DSP is tightly integrated into the ARM CM7 core, you may use the MCU development tools (and not specific DSP tools) for developing your code. Since February, the ATSAMV71-XULT (full-featured Xplained board, SAM V71 Xplained Ultra Evaluation Kit with software package drivers supporting basic drivers, software services, libraries for Atmel SAMV71, V70, E70, S70 Cortex-M7 based microcontrollers) is available from Atmel. As this board has been built around the feature-rich SAM V71, you can develop your automotive application on the same exact MCU architecture as the part going into production.

SAMV71 Ultra Xplained - Atmel ARM Cortex M7

Versatility and Integrated DSP built into the ARM CM7 core allows for MCU development tools to be used instead of having to revert to specific DSP tools. You can develop your automotive application on exactly the same MCU architecture than the part going into production.

Interested? More information on this eval/dev board can found here.

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The next arrow of development is set for automotive

What is happening now?

What is resonating from the sales floor and customer perspective?

Proliferation of the stack

Where lies innovation and change is disruption

What can we do now in the invention, design and development process?

How to get started

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AVB Design Considerations

AVB and Cortex-M7 MCUs

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Built-in Security

Software Support

Transition from MPU to MCU

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Atmel’s Memory Play

Cortex-M7 a DSP Winner

The SAM E70, V70 and V71

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