Sophisticated graphics have hit the embedded systems world and are increasingly demanded by military, aerospace, industrial, and medical applications. The problem, of course, is that graphics are challenging even in the desktop world. In embedded designs, they present unique issues that include very specific, non-standard functionality.
Take an airplane cockpit. It may need to drive three or more screens, each displaying different information deriving from, and possibly combined from, different sources. A tank may have a similar requirement, but what’s displayed on the screen in the tank is likely to be different because (at the very least) the tank has to do without windows. Meanwhile, a control room might have six tiled screens on a wall that could be combined into a single large image or present up to six separate images.
Applications like these may share little in common, except the use of a display. The information to be displayed may arrive through existing video streams or from elsewhere in the form of raw data. It may go out as one or more video streams, or it may be sent as raw information somewhere else to be further processed. Input and output video streams may be transported as a number of different video formats or over some other channel like USB 3.0 or Ethernet. They may need to drive monitors or analog displays, and they may need to do so over modern HDMI cables or old-fashioned RGB signals.
The actual processing may be as diverse as the possible signals. Requirements may be as straightforward as frame grabbing, AES128 encryption, or compression using a standard like H.264, or it may require a general-purpose graphics processor to implement specific custom processing. Different systems employ these functions in custom combinations. And most of them have severe size and/or weight constraints that mandate the most compact possible implementation.
These functions can be implemented on mezzanine cards affixed to a standard carrier board like Eurocard (VPX, CPCI, or VME) or COM Express baseboards. But the card must accommodate a large number of video channels (inbound and outbound) and formats as well as the ability to exchange data quickly over a format like PCI Express (PCIe). Graphics standards like SDI can signal at speeds over 3 Gbps, and intercard data may need to move at speeds exceeding 5 Gbps. Finally — and perhaps most critically — space is best economized if multiple modules can be placed on the carrier cards.
These parameters can be compared for the most common mezzanine boards, ranging from the aging PMC card; its updates, the XMC and the FPGA-oriented FMC cards; and the MXM 3.0 format (specifically geared towards video in laptops). A quick inventory of these formats, shown in black in Table 1, readily shows that high-end graphics and video processing exceed their capabilities, and that an alternative is needed. The existing standard form factors (black) cannot meet the needs of advanced graphics designs, meaning that a new form factor (MXC, in blue) is needed.
The new MXC form factor from Wolf Industrial Systems, shown in blue in the table, specifically targets the high-end video requirements of analog, digital, and broadcast SMPTE inputs and outputs, video mixing and overlay, H.264 compression, and AES128 encryption.