Version 1.1 The flagship of small form factor modules Qseven Computer-on-Modules Author: Claus Giebert E-mail: [email protected] www.advantech.com Design considerations in the small form factor segment of Computer-on-Modules are critical these days as three form factor standards compete for the favor of engineers. At the end of the day, most will pick Qseven as recent studies predict. What is the secret behind these design considerations? Engineers tasked with building small, space-constrained smart devices with low or ultra-low power x86 or ARM processor technologies are facing the challenge that standard motherboards and single board computers usually don’t have the right setup for their applications. In most cases, the footprints of standard boards are too large while the interfaces provided are often not those needed and/or there are too many and/or they are not located where they are demanded. Full custom designs can address all these needs with perfectly tailored boards. But custom designs are very time consuming and expensive to develop; they are also maintenance intensive from a software point of view and require conscious efforts in obsolescence management for each component over their entire lifecycle. Therefore, they are only recommended for high-volume devices. Universally available Computer-on-Modules, however, make customization both faster and more cost efficient; they are suitable even for smallest volume series productions with only a few hundred boards per year; and the entire servitization for this computing component is carried out by the vendor. Computer-on-Modules: A highly reliable choice Computer-on-Modules are application-ready embedded computers with all relevant drivers, libraries and APIs pre-integrated. In combination with carrier boards, they can be designed to fit exactly the required shape and interfaces are located where the applications need them – and this most often without the use of cables. Designing these carrier boards is less complex compared to full custom designs; and design guides, evaluation boards and schematics as well as board design tutorials help engineers to develop carrier boards in a highly efficient and state-of-the-art manner. On top of all this, the standardization of Computer-on-Modules adds very high design security and enables even second source purchasing strategies. Commercially of-the-shelf available accessories such as cooling solutions or display cables further contribute to increased design efficiency. All these arguments have led to the widespread adoption of Computer-on-Modules in embedded computing solutions. No other embedded computing platforms such as motherboards, SBC, slot boards or platforms for passive backplanes have a broader acceptance as recent studies from IHS found out. So picking a Computer-on-Module for designing a custom solution is by far the most accepted and reliable choice. Picking the right small form factor However, within the sector of small form factor Computer-on-Modules it is not that easy to identify the right specification from a technical point of view as there are three competing form factor standards today: Qseven, SMARC 2.0 and COM Express Mini. But why do recent studies estimate that Qseven is the standard with by far the largest market share and strongest growth prospects so that this form factor will still be the leading form factor with the highest market penetration in 2020? There are several arguments that are highly convincing. 2 www.advantech.com Qseven has the broadest vendor support A current market analysis of main market drivers shows that Qseven has the broadest market support: 45 40 Small form factor 35 30 25 20 15 10 5 0 SMARC COM Express Mini Qseven Caption: Qseven has the broadest product portfolio publicly available at the websites of the standardization bodies SGET and PICMG. These results are a significant and undeniable indicator for the fact that there is a massive competitive gap between the Qseven offerings and its followers, COM Express and SMARC 2.0. And this competitive edge is definitely a plus factor for Qseven. Qseven is platform agnostic Another plus factor lies in the fact that Qseven modules support not only x86 but also ARM platforms such as the iMX.6 processors from NXP. This makes this form factor by far more attractive for embedded system engineers as both leading low and ultra-low power processor technologies are supported. Not only can the Wintel approach be extensively addressed but also Android ARM platform developments – and all this with a single form factor. COM Express Mini does not support this segment to date, making this form factor only suitable for engineers who work in the PICMG COM Express ecosystem and with larger form factors. If engineers want to be open for ARM, they can only consider SMARC 2.0 or Qseven. And it is strongly recommended to be open in the small form factor sector as ARM is dominating this segment in the commercial and consumer electronics sector. So what differentiates the new SMARC 2.0 form factor from the established and well developed Qseven form factor? Is SMARC better than Qseven because it is brand new? 3 2017 ARM x86 2021 ARM x86 Caption: Qseven is available for both x86 and ARM architectures. Analysts predict that the market share of ARM modules will increase. SMARC 2.0 is just an extended Qseven specification Qseven offers all the major interfaces demanded and there is not that much that differentiates the SMARC 2.0 specification, launched in 2016, from Qseven, launched in 2008. But surely, SMARC 2.0 must be better because it is brand new? Undisputedly the SMARC standard offers more signal pins and uses the latest connector version. But does this really matter? What are the new interfaces that are better supported by SMARC 2.0? A closer investigation reveals that there are not that many unique features compared to Qseven, if any. Designers are advised to beware and not to trust all the marketing hype around SMARC 2.0 as the real differentiating factors between SMARC and Qseven are little. In the end, they boil down to support of up to 4 independent displays instead of 3, and camera support via an edge connector instead of the flat foil cable used on Qseven. This makes SMARC 2.0 a little bit but not massively more attractive for multimedia oriented applications. As a consequence, the huge existing base of already deployed installations will stay within Qseven and benefit from the huge and stable footprint in the market. So nothing speaks against the ‘good old’ Qseven form factor except if applications definitely need 4 display ports or want to save costs for the MIPI camera cable. Even the old connector obsolescence arguments are outdated because the Qseven connector has now more vendors than the SMARC connector offers today. All these facts explain why Qseven will stay the most dominant computer-on-module standard for small form factor applications for many years to come even if all the other form factors will show good growth as well. The following quick top-down evaluation provides engineers with the most important selection criteria for picking the right small form factor computer-on-module. These can be summarized as follows: 4 If you are not a pioneer in smart vision and don’t need a 4th display – which by the way is not supported by current SoCs – then Qseven offers you by far more freedom of choices than SMARC 2.0. If you are not conjunct with the larger form factors of PICMG’s COM Express specifications and don’t have the need to re-use this ecosystem then Qseven is far more suitable for you than COM Express Mini Type 10 modules. What can engineers expect from Qseven modules? Let’s start with the basic feature set: Qseven comes in two sizes: 70 x 70 mm and 40 x 70 mm (aka Size µQseven). Qseven provides an MXM2 compliant finger connector at the Connector edge of the board. This connector is flat, rugged and cost effective. The pinout to the carrier board features 230 pins. SMARC has Pinout more pins (314); COMe Type 10 less (220). Gigabit Ethernet, USB 2.0 and 3.0, sound (HDA & I2S), video Standard device (DisplayPort, TMDS, LVDS), camera over additional flat foil interfaces connector (MIPI CSI) Internal extensions PCI Express, LPC (suitable for TPM), SDIO Storage SATA and/or PCIe Management Additional control and power management signals Max TDP target Up to 12W Major customization levers are the PCB form factor, the location of the interfaces – here even the decision not to route all of Qseven’s supported interfaces to the carrier board is an important customization factor – as well as the internal extension busses PCI Express, LPC, and SDIO. PCIe support is compliant to the latest 3.0 specifications offering up to 32 Gbit/s over 4 lanes for any high speed peripheral interface demands such as further Ethernet ports or additional ultra-fast USB 3.0 ports. The SDIO interface is perfectly suited for SD cards as well as for I/O devices such as GPS receivers or wireless interfaces and modems. Finally, the LPC bus is another feature that will underpin Qseven’s long term success as SMARC 2.0 no longer supports LPC. Why is LPC so important? Many embedded computing platforms rely heavily on this bus as it is simple to use, far less complex than PCI/PCIe and the primary substitute for most legacy ISA bus applications. Supporting what is deployed in the embedded fields is an important lever to success. This can be easily validated by having a look at the ETX/XTX market share with its legacy ISA and PCI bus.