Power
Sponsored by
Why is low power consumption so critical in smart devices?
By Liem Tran, applications & development engineer, Anders S
mart devices are spreading everywhere and, whether they run from mains electricity, a battery, or energy harvesting, minimising their power and energy requirements is critical; both to ease the management of large numbers of devices and to “green” the IoT edge. On the other hand, each successive generation – whether a smart sensor, IoT gateway, autonomous controller, smart appliance – is expected to provide more capabilities and capacity, handle more complex situations more intelligently, and respond more quickly. Traditionally, microcontrollers have been the main choice in power-conscious systems such as those used in IoT applications. However, with the increasing demand of processing power, microprocessors are being sought out.
How do the latest embedded processors help minimise power consumption?
As the apparently conflicting demands for lower power with greater performance and sophistication intensify, frugal power management is increasingly important using techniques like granular low-power operating modes with gating of clock signals to halt specific peripherals and power gating of unneeded domains to avoid leakage current. Ch ip designers refine and improve these with each generation of devices. In addition, further innovations continue to extend the power-conscious embedded designer’s toolbox; like the Energy Flex architecture of the
i.MX 8ULP and
i.MX 8ULP-CS families announced recently by NXP.
As well as the intrinsic energy savings gained through the latest 28nm FD-SOI process technology, the Energy Flex architecture features advanced design techniques and heterogeneous domain processing. Application-level processing
42 June 2022 Components in Electronics
running a rich operating system on the chip’s Cortex-A35 cores is separated from real-time processing managed by an RTOS running on the Cortex-M33 embedded- class core. An optional Fusion DSP in the real-time domain handles low-power keyword detect, and there is a separate
Flex domain with a HiFI 4 DSP for advanced audio and voice processing. Altogether, Energy Flex improves efficiency by up to 75 per cent.
Then there is the µPower subsystem, controlled by a dedicated core, which is implemented specifically to handle power
management. This can manage more than 20 different power-mode configurations across processing domains, helping developers properly utilise the flexible power-saving opportunities available.
What power-management features are available in
i.MX 8 processors?
These features of the new ULP devices build on techniques employed in other
i.MX processors such as the
i.MX 8 families to minimise wasted power. The Arm platform, L2 cache, PLL and peripherals are managed as separate power domains. Independent clock gating to the peripherals limits dynamic power by halting operation. Clock gating can be turned on and off quickly, although some leakage current occurs because the peripheral continues to receive power for biasing. Power gating tackles leakage by removing the biasing and can be applied on-chip or at the power supply.
i.MX processors allow individual power gating to the Arm, PLL, and peripheral
www.cieonline.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58
