Arm + Cypress: Smart Memory Architectures | 赛普拉斯半导体
Arm + Cypress: Smart Memory Architectures
Unique Memory Architecture Enables Enhanced Functional Safety and Reliability for Automotive Applications.
Cypress Semper™ NOR Flash memory is architected and designed to exceed functional safety requirements, and a pivotal design element is the embedded Arm® Cortex®-M0 core. The microprocessor enables key features including flexible wear leveling, extensive error reporting, and operational recovery. These capabilities combine to help ensure that critical automotive systems work all the time, every time.
In this blog we discuss our fail-safe memory and how we are uniquely positioned to solve complex safety and reliability problems by adding a compute processor inside our Semper NOR Flash memory.
Check out the Q&A below with Automotive experts Sandeep Krishnegowda, Product Marketing Director from Cypress Semiconductor and Antonio Priore, Sr. Functional Safety Manager from Arm.
We hear a lot about functional safety in the automotive industry, but what exactly does that mean?
Antonio Priore: The automotive industry is relying more and more on electronic systems to solve real-time, complex problems. In a moving vehicle, failure prevention and recovery in these mission-critical systems is paramount. In this context, the industry is guided by the ISO 26262 functional safety standard. It sets the requirements for designing safe automotive systems and is the standard that applies to the entire automotive supply chain.
Sandeep Krishnegowda: ISO 26262 defines functional safety as “The absence of unreasonable risk due to hazards caused by malfunctioning behavior of electrical/electronic systems.”In electronic systems, the cause of failures leading to system malfunctions can be systematic faults in design or random faults due to soft error or probabilistic reliability failures over time. The ISO 26262 standard defines safety integrity levels that are classified from ASIL A to ASIL D, with each level being derived from parameters such as: 1) greater probability of an event, 2) increasing degree of harm or injury from an event, and 3) the capability for the driver to control and influence the event. The key goal of functional safety is to prevent accidents from happening by reducing the risks to acceptable levels. We reduce systematic failures during development (quality) and add safety measures to detect and mitigate random failures during operation.
The diagram above shows an example of how safety is implemented in automotive systems today, and the safety process that is followed by vehicle manufacturers, system suppliers, and component suppliers.
What role does NOR Flash play in automotive safety-critical systems?
Sandeep Krishnegowda: Automotive applications use external NOR Flash memories in safety-critical applications such as ADAS, Powertrain, Gateway, and Clusters for storing critical code, data, and graphic images that must be read at system power-up or during operation. Safety requirements for these external flash memory solutions depend on the different use cases. There are several types of failures that can happen inside a Flash device. Bit flips caused by charge loss in a flash cell can lead to incorrect data reads, which can subsequently hinder safety. Consider an instrument cluster application where display icons (e.g., a seat belt or other warning sign) is stored in a NOR Flash device. A corrupted read could lead to a blurred image being displayed on the cluster dashboard. It is important to have the safety mechanism inside the Flash memory to protect against failures and safety reporting to prevent operational failures.
Why is the Arm Cortex-M0 processor such a key part of the Cypress solution’s ability to meet the ISO 26262 standard?
Antonio Priore: First, Arm understands functional safety and automotive design challenges quite well and has also architected solutions with those requirements in mind. Adding the Cortex-M0 processor to a standard memory offers the capability to address new problems that can now be solved inside the memory. Semper NOR Flash enables processing of complex embedded algorithms, detection and correction of memory errors, functional safety diagnostics, and partition management. It’s also ideal for overseeing the boot process, as in an ADAS implementation you can’t afford for the memory to fail or be compromised.
Cortex-M0 also enables intelligent wear levelling: storage can be partitioned and configured for either 25 years of data retention or write endurance of over 1.25 million writes. That’s essential for the reliability aspects of ISO 26262.
In short, for Cypress, the Cortex-M0 provides in-memory compute capability for solving complex safety and reliability problems without adding significant area and power to the solution.
Tell us why Cypress’ Semper NOR Flash solution is well suited to meet the functional safety requirements for the automotive industry?
Sandeep Krishnegowda: First, the product itself is truly a groundbreaking design, a completely new, differentiated approach to NOR Flash memory design. It is architected and designed specifically to exceed the ISO 26262 standard for building fail-safe embedded systems. As such, the family is AEC-Q100 automotive-qualified, ASIL-B compliant, ASIL-D ready, and provides the operational performance and reliability automotive makers need, such as providing superior endurance (1+ million cycles) and 25 years of data retention at extreme temperatures (-40°C to +125°C) common in automotive applications.
Second, safety and reliability are in Cypress’ DNA. Cypress has been associated with automotive functional safety for more than 15 years and is one of the industry’s leading providers of functionally safe automotive products (MCU, analog PMIC, memory, and software). Cypress understands well the process and documentation requirements and has an internal group of experts responsible for defining and maintaining these standards from the beginning to the end of a project. These experts ensure that our products fulfill the ISO 26262 safety standards.
Can you talk about the challenge and complexity of adding compute to Cypress memory?
Sandeep Krishnegowda: As with most major product developments of this type, Cypress worked with major suppliers to help define the requirements and implement the needed technology. In addition, Cypress partners broadly with Arm on a variety of products, including our Traveo and PSoC microcontrollers, and our knowledge of Arm and their technology enabled us to develop the Semper solution quickly. The Arm ecosystem is a very robust one and using industry standard tools sped our software development. Flexibility was key as well since the chip had to meet multiple standards as functional safety applies to areas beyond automotive, such as industrial automation and robotics.
Have any questions that you didn’t see answered here today? Tweet them to us at @CypressSemi using #CYSmartSolutions.