Hi,
Can you give me a concrete example of an application requiring the cortex-R family (exept for the watch and the video-recording). Given the gap in price between processors, Except in the case of a large-scale purchase why not choose the cortex-A family ?
regards,
Hi Jerome,
sorry for the late reply (I've been on holiday). Regarding specific application examples, one of the challenges of finding deployments of Cortex-R cores is that they are often deeply embedded into designs, sometimes along Cortex-A cores too, and not all partners want to highlight that they are using our cores. As others in the thread have highlighted, they come into their own where hard real-time performance is required, and a great example of this is disk drives:
http://www.arm.com/markets/embedded/hdd-ssd.php
Both SSD and HDD use Cortex-R (although we are seeing both -M and -A families being used in some devices too now).
They are also widely used in LTE modems in mobile phones:
Five things you may not know about Cortex-R Series processors
ARM Cortex-R real-time processors speed your mobile communications
As others have listed above, the main difference between A and R families is the addition of TCMs, and the change from MMU to MPU. However the Cortex-R family also has other features to help with real-time applications such as low-latency peripheral ports (designed to allow fast access to peripherals without transactions getting held up by other bus traffic), and interruptable Load-Store multiples (if an interrupt arrives during an LDM/STM operation to normal memory, the transaction can be abandoned to take the interrupt. It is then repeated after the interrupt handler completes).
Jon
It is a good use of the Cortex -R. Thanks for this very telling example !
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