This is a MCU series which combines rich digital and analogue capabilities with a low-power on-chip neural processing unit (NPU) in a new compact form factor.
The Ensemble family MCU combines a 160MHz Arm Cortex-M55 CPU core with Helium vector processing extension, an Arm Ethos-U55 NPU generating up to 46 GOPs, and up to 2MB of tightly coupled SRAM in a WLCSP package occupying a footprint of just 3.9mm x 3.9mm.
The introduction of the E1C extends the scalable Ensemble family, providing a new entry-level option for OEMs that want to take advantage of Ensemble’s combination of high AI performance and ultra-low power consumption implemented in a familiar Arm environment.
The E1C also shares the same architecture as the Balletto family, allowing for software re-use across the entire family, and easy migration of applications from one device to another.
Thanks to the efficient ML inferencing performance of the Ethos NPU and an advanced aiPM power management system, the E1C can perform both AI/ML and application control functions at ultra-low power levels, which means that manufacturers can bring advanced ML capabilities to products such as wearable devices that have extreme constraints on power and space.
The E1C’s capabilities have been optimised for local ML workloads such as object recognition, speech recognition, sensor fusion, and adaptive audio noise cancellation, easing heavy dependence on the cloud to provide a better user experience.
The high AI performance of the E1C is combined with power efficiency. The E1C’s aiPM technology can dynamically power only the logic and associated memory that are in use at any given time, achieving the lowest overall system power consumption. The aiPM power management unit implements four system-level power modes including a Stop mode which draws just 700nA.
The Ethos-U55 NPU performs 128 MACs/cycle to give ML output of 46 GOPS and enables on-the-fly weight decompression. This results in inferencing performance some 100x faster and more power-efficient than competing MCUs based on an Arm Cortex-M4 CPU provide.
The E1C’s digital cores are backed by up to 2MB of MRAM non-volatile memory alongside up to 2MB of zero wait-state SRAM. A high-speed OctalSPI interface enables expansion to external memory if required. Versions of E1C devices are offered with and without the NPU.
Providing a high level of system integration, the E1C features a rich set of analogue and connectivity peripherals. Two 12-bit SAR ADCs and a 24-bit sigma-delta ADC, a 12-bit DAC and an internal reference voltage provide for fast, precise processing of signals from external sensors. Outputs can be displayed on rich colour displays using a MIPI DSI display interface.
A broad selection of serial communications interfaces includes USB 2.0, SDIO, 2x CAN FD and I3C. Designers of connected devices can also benefit from the same low-power and high-performance characteristics of the E1C with the addition of built-in Bluetooth Low Energy connectivity by choosing the Balletto B1, launched earlier this year.
Comprehensive security is a core attribute of the Ensemble family, and the E1C shares the same architecture. Its advanced secure enclave, which provides a solid hardware root-of-trust enabling secure key generation and storage, secure boot, cryptographic accelerators, and certificate management, eliminates the need for an external Secure MCU in endpoint AI devices.
The E1C is available in three package options:
- For maximum space savings – 90-bump WLCSP
- For maximum I/O while requiring only 4 PCB layers for routing – 120-bump FBGA
- For maximum durability in harsh environments – 64-lead TQFP
All Ensemble MCUs, including the E1C, are fully compatible with the Arm ecosystem of tools, development environments and software resources for efficient system development. For evaluation of the E1C, Alif supplies the DK-E1 development kit.
E1C devices and DK-E1 kits will be available to lead customers in August 2024 with production ramping in 4Q24.
