NXP unveiled a Linux-friendly i.MX8M Nano SoC with the same up to 4x 14nm Cortex-A53 cores as the faster, pin-compatible i.MX8M Mini, but with no VPU and a 600MHz Cortex-M7 instead of an -M4.

This week’s Embedded World show in Nuremberg has been awash in new products built around the i.MX8M Mini, including Ka-Ro’s TX8M and CompuLab’s UCM-iMX8M-Mini modules and Boundary Devices’ Nitrogen8M-Mini SBC. Next year’s show may well be showcasing the newly announced i.MX8M Nano, a pin-compatible spinoff of the Mini which similarly offers up to 4x 14nm fabricated Cortex-A53 cores. However, the Nano has a slower clock rate and it lacks the Mini’s VPU.

i.MX8M Nano and block diagram
(click images to enlarge)

On the other hand, the Linux and Android-compatible i.MX8M Nano has more advanced audio processing and appears to have lower power consumption. It also swaps out the 400MHz Cortex-M4 MCU for a more powerful, 600MHz Cortex-M7 chip.

NXP also announced that it was collaborating with Microsoft to bring the Azure IoT Edge cloud IoT framework to all three i.MX8M SoCs “across Linux and Windows 10 IoT core OS.” The i.MX8M family includes the Nano, the Mini, and the flagship i.MX8M. Customers will be able to deploy and manage IoT Edge container applications from the Azure cloud dashboard, says NXP.

 
Inside the i.MX8M Nano

Like the i.MX8M Mini, the i.MX8M Nano uses a more advanced 14LPC FinFET process than the i.MX8M, enabling lower power consumption a smaller, 14 x 14mm footprint. In the case of the Mini, this also enables a faster 1.8GHz clock rate than the i.MX8M, which like the Nano, tops out at 1.5GHz.

Whereas the i.MX8M supports 4K resolution and the Mini supports HD, the Nano lacks a video processor unit altogether. MIPI-DSI driven HMI applications are enabled via the Vivante GC7000UL 3D/2D GPU.

Most of NXP’s recent i.MX7 and i.MX8 SoCs have been equipped with a 266MHz Cortex-M4 SoC supported with FreeRTOS. The Mini boosted this to 400MHz, and the Nano advances to an unidentified 600MHz Cortex-M7.

It’s unlikely this is a variant of NXP’s 600MHz, -M7 based i.MX RT “crossover” processor, which was announced in Nov. 2017 as the world’s fastest Cortex-M processor. The cache allotments don’t quite match up with the 600MHz i.MX RT, although it’s hard to say since NXP lists a pair of 16KB caches for the -M7 in the spec list but 32KB caches in the block diagram. It’s unlikely that NXP would fail to mention the presence of the i.MX RT, which integrates a PxP 2D accelerator and is even capable of running uClinux.

The Nano appears to have lower power consumption than the Mini. While the Mini was touted for having lower consumption than the i.MX8M, with “ultra-low-power, even sub-Watt in specific applications,” the Nano is said to offer “less than 2W total dynamic power (TDP) and sub-watt in many IoT applications.”

Elsewhere in the Nano announcement, NXP states: “Power consumption of less than one watt is possible in many IoT applications even with all four Cortex-A53 cores running, making it ideal for power-sensitive edge computing applications. The real-time processing domain powered by high-performance Cortex-M7 core (up to 600MHz), enables further power reduction through task offload from Cortex-A cores, power-optimized audio playback, low-power system-level task monitoring and more.” Still, this is unlikely to be as power efficient as NXP’s up to quad-core, Cortex-A35 based i.MX8X.

 
Enhanced audio processing

If the Nano is a bust when it comes to video, it’s optimized for audio applications. The SoC is touted as NXP’s first to offer “hardware acceleration for asynchronous sample rate conversion (ASRC) for up to 32 channels of high-quality audio streaming with extremely low noise and distortion.”

The peripheral support of the i.MX8M Nano is much like that of the Mini. However, it’s limited to a single USB 2.0 OTG controller instead of two, and we see no mention of PCIe support. In addition, external RAM memory support is 16-bit vs. 32-bit for the Mini.

Common features to both SoCs include GbE, MIPI-DSI and -CSI, and other I/O listed in the block diagram above. For the temperature support, NXP must have had global warming in mind: the “consumer” model offers a generous 0 to 95°C and the industrial model goes to -40 to 105°C

The i.MX8M Nano will be supported with the same sandwich-style, COM-and-carrier Nano EVK development kit available for the i.MX8M Mini. The EVK’s core module supports LPDDR4, DDR4, DDR3L, and eMMC, and includes a PMIC and a soldered-down WiFi/BT module.

Given the pin-to-pin and software compatibility between the SoCs, it’s likely we’ll see variants of existing third-party Mini boards that offer the Nano, or even give you a choice of either SoC. The Nano is also software compatible with other i.MX8 family SoCs.

 
Further information

The i.MX8M Nano will start sampling in Q2, with mass production due in Q4. More information may be found in NXP’s Nano announcement and preliminary product page.