Legacy That Stacks Up
With roots that grew from the ISA-bus era, PC/104 has grown into an embedded board-level form factor suited to the PCI Express landscape. For space-constrained applications, PC/104 and all its follow-on variants continue to meet system design needs.
Since its creation over 25 ago, PC/104 has enjoyed one of the greatest success stories in terms of leveraging technologies from the PC infrastructure. The well-established PC/104 standard is remarkable for opening the door to the embedded stackable computing concept. It began with the ISA bus and over the years has grown to include the latest innovations in desktop computing technologies with PCI and PCI Express. PC/104 evolved through the era of PCI and PCI Express by spinning off its wider family of follow on versions including PC/104-Plus, PCI-104, PCIe/104 and PCI/104-Express.
The PC/104 architecture demonstrates that it’s possible to successfully implement quickly evolving PC technology into embedded computing products by taking advantage of PC market adoption, performance, scalability and growing silicon availability worldwide. PC/104 was designed to be simple in design, but rugged in performance. As a result, PC/104 products have permeated many industries. A PC/104 board provides the computing inside Klein’s UUV-3500 high resolution side scan sonar for unmanned underwater vehicles. The system is used on OceanServer Technology’s Iver3 AUV (Figure 1).
A couple years ago the PC/104 Consortium made a revision to PCI/104-Express and PCIe/104 that provides an additional option called “OneBank”. The PCIe/104 OneBank utilizes a smaller, lower-cost bus connector which is compatible to the full size PCIe/104 connector currently in use today. It allows designers to stack boards using a complimentary format that frees up PCB real estate for additional components as well as potential cost savings. The OneBank connector concept consists of removing two of the three “banks” of the standard PCIe/104 connector, resulting in a 52-pin connector as opposed to the full-size 156-pin connector.
Among the more recent trends in PC/104 has been roll out of boards that include Mini PCIe sockets. Mini PCIe lets system designers mix and match add-on functions, leveraging the emerging ecosystem of Mini PCIe peripheral cards as they become available. The product gallery on the next couple pages shows a mix of board designs upgraded to sport the latest processor and memory technologies. Because most of these boards are based on Intel processors, most all of these boards run the Linux operating system. These are representative examples of PC/104, PC/104-Plus and PCI/104-Express board-level products.
PCIe/104 SBC Boasts Extended
The ADLE3800PC from ADL Embedded Solutions is based on Intel’s SoC E3800 Atom product family. The board is well suited for rugged, extended temperature intelligent systems. It has a wide thermal junction temperature (Tj) ranging from -40°C to +85°C. Intel’s 7th generation graphics engine on the processor is capable of decoding 10 or more streams of 1080p video and has integrated hardware acceleration for video decode of H.264, MVC, VPG8, VC1/WMV9 and others standards.
• Intel E3800 Series SoC Processors; Dual/quad
• Up to 8 GB DDR3L-1333; 1.35 V SoDIMM204 socket
• CPU TDP 8 W to 10 W
• Type 2 downward-stacking PCIe/104 V2.01
• 2x Gen2 PCIe x1 lanes
• 2x SATA 3 Gb/s; shared with mSATA socket
• 2x 10/100/1000 Mbit Ethernet LAN port
• 2x RS232 COM ports
• 8x USB 2.0 total
• Microsoft Azure certified for loT
PCI/104-Express Type 1 SBC Sports 6th Gen Core i3
ADLINK Technology’s CMx-SLx is a PCI/104-Express Type 1 SBC featuring the 64-bit Intel 6th gen Core i3 processor (formerly “Skylake-H”), supported by the Intel CM236 Chipset. The CMx-SLx is specifically designed for customers who need high-level processing and graphics performance in a long product life solution. The CMx-SLx Intel processor supports Intel Hyper-Threading technology and 8/16 GB of soldered ECC DDR4 memory at 1866/2133 to achieve optimum overall performance.
• 6th gen Intel Core processor (formerly codenamed Skylake)
• Up to 16 GB DDR4-ECC soldered memory
• 3x DDI channels, 1x micro HDMI, 1x mini DP and 1x 18/24 bit single channel LVDS
• 4x PCIe x1 and 1x PCIe x 16 (PEG)
• 2x GbE LAN, 2x SATA 6 Gb/s, 1x USB 3.1, 6x USB 2.0, 2x COM, 8x GPIO
• Supports Smart Embedded Management Agent (SEMA) functions
• Extreme rugged operating temperature -40°C to +85°C variant
Atom-based PC/104-Plus SBC Boasts Low Power Operation
Advantech’s PCM-3365 is a PC/104- Plus SBC with an Intel Atom E3825/ E3845/ N2930 processor, supporting DDR3L SDRAM and soldered flash up to 64 GB. PCM-3365 offers an extend temperature SKU with E3825/E3845 SoC. The Thermal Design Power (TDP) rating for the SoC is only 5.7 W for E3825 (the lowest), and 7.7 W for E3845 (the highest). The card is PC/104-Plus form factor which means it supports both ISA and PCI bus through PC/104
and PCI-104 connectors.
• Intel Atom E3825/E3845 and Celeron
N2930, DDR3L-1066/1333 SODIMM
up to 8 GB
• DirectX11, OpenGL3.2, OpenCL1.1,
3 independent displays: VGA+LVDS/
HDMI+LVDS/ DVI+LVDS/ VGA+LVDS
• Support PC/104-Plus expansion
• 1 Gbit Ethernet, 3x COM, SATA,
6x USB2.0, SMBus/I2C, GPIO, fullsize
Mini PCIe/full-size mSATA
• Supports SUSIAccess and Embedded Software APIs
PCI/104-Express Card Provides 20- or 8-Port Gbit Ethernet Switch
The Parvus SWI-22-10 from Curtiss Wright Defense Solutions is a rugged Gbit Ethernet switch card optimized for SWaP sensitive embedded military and civilian computer network systems applications. Featuring advanced Layer 2 networking features with from 8- to 20-ports of 10/100/1000 Mbps connectivity, an integrated management processor, low power consumption, and robust carrier Ethernet software features, the SWI- 22-10 enables reliable LAN switching across -40°C to +85°C temperature ranges.
• Rugged embedded Gigabit Ethernet switch
• 20 port and 8 port versions
• Layer 2 fully managed network switch with Layer 3 static routing capability
• Low-power, Energy Efficient Ethernet (802.az) compliant
• IEEE-1588v2 Precision Timing Protocol (PTP) support
• Qual tested to MIL-STD-810 for 40°C to +85°C and high shock/vibration
1 GHz Vortex86DX3 PC/104 Board has On-board Data Acq
Diamond Systems’ HELIX PC/104 SBC is based on the DMP Vortex86DX3 system-on-chip (SoC) processor. It offers high feature density in a compact size and providing optional integrated high-quality data acquisition circuitry, PCIe MiniCard I/O expansion and
rugged construction. Two standard Helix models are available off-the-shelf; one aimed low-cost basic applications and the other targeting data acquisition applications.
• 1 GHz dual core DMP Vortex86DX3
• Up to 2 GB of on-board 64-bit DDR3 SDRAM
• 24-bit LVDS LCD and VGA CRT display support; 1920 x 1080 maximum resolution.
• A broad range of system I/O, including 4 multiprotocol serial ports, 6 USB ports, 2 10/100/1000 Ethernet ports, and 1 SATA port
• PC/104 (ISA) and PCIe MiniCard / mSATA sockets
• Optional data acquisition circuitry: 16 16-bit A/D channels, 4 16-bit D/A channels, and 11 programmable digital I/O lines
PCI/104-Express SBC Marries 1.9 GHz Atom and 32 GB SSD
The CML24BT from RTD Embedded Technologies is an advanced PC/104 single board computer with a PCI/104- Express stackable bus structure. This Intel Atom based CPU is exceptionally suited for intelligent systems requiring low power consumption in harsh thermal conditions. The surface-mount Type 2 PCI Express connectors enable users to stack multiple peripheral modules above and below the CPU.
• PC/104 form factor, PCI/104-Express stackable bus structure, PCIe Type 2 expansion buses
• Intel Atom E3800 Series Processor; 1.33 GHz, 1.46 GHz and 1.91 GHz options
• Single-Channel DDR3 SDRAM surface mounted with ECC
• Surface-mounted industrial-grade SATA 32 GB flash drive
• 4 x1 PCIe Links; 1 SATA Port; 4 Serial Ports (RS-232/422/485); 7 USB; Gbit Ethernet; DisplayPort, DVI and HDMI
• -40°C to +85°C standard operating temperature
PCIe/104 OneBank SBC with FPGA and Two Dual-DSPs
The SMT6657 DSP+FPGA module from Sundance Multiprocessor Technology is a reliable and flexible platform for DSP applications requiring high-performance integer and floatingpoint computation. It is applicable to both symmetric multiprocessing applications in which the computational load is shared by the two DSPs and asymmetric applications where one of the DSPs is responsible for hard realtime processing and the other acts as a supervisor.
• PCIe/104 OneBank SBC
• Two TI dual-core 1.24 GHz TMS320C6657 floating-point DSPs
• Xilinx Kintex-7 UltraScale KU35 FPGA
• Serial RapidIO and Hyperlink connectivity between DSPs
• Accepts one VITA57.1 FMC-LPC Mezzanine Card data acq add-on module
• Additional stack-down Serial RapidIO connector to SMT-Carrier-GSI
• Front panel I/O connector carrying Gbit Ethernet and flexible FPGA I/O
Dual 10 Gigabit Ethernet Expansion Module VL-EPM-E9E
The “E9” module is an extremely rugged dual 10 Gigabit Ethernet add-on expansion
card, for use with copper cabling. With its stack-down three-bank PCIe/104 pass-through
connector, it is ready for inclusion in a PC/104 stack. On-board magnetically isolated
RJ45 ports make for easy connection to other network nodes
• Dual 10 Gigabit ports
• High speed edge networking
• PCIe/104 format
• 3-Bank Type 1 stack-down
• Extremely rugged
• Designed and tested to MIL-STD-202. Full -40°C to +85°C operating range
PC/104-Plus SBC Sports Dual Core Bay Trail SoC
The SandCat from VersaLogic is a low-power dual-core SBC with an industry-standard PC/104-Plus expansion interface. This combination enables easy upgrades to existing PC/104 systems to Intel’s long-life Bay Trail processor, while preserving plugin expansion to existing specialty I/O boards. The board also contains onboard I/O interfaces, including USB, a mini PCIe expansion socket and digital I/O ports.
• 1.33 GHz Intel Bay Trail Processor, dual core
• Integrated Intel Gen 7 graphics core supports DirectX 11, OpenGL 4, and H.264, MPEG-2 encoding/decoding. Mini DisplayPort video output
• Up to 8 GB DDR3L DRAM
• Ethernet interface, 2x RS-232/422/485 serial ports; 4x USB 2.0 ports, three 8254 timer/ counters, I2C and audio support
• Industry-standard PC/104 and PC/104-Plus expansion
• -40°C to +85°C operation
• MIL-STD-202G qualified for high shock and vibration
Rugged SBC Features 9th Gen Xeon-E Processor
VersaLogic’s Eagle (EPU-5120) is a rugged board-level embedded computer that features a Xeon-E processor and soldered down NVMe SSD storage. It provides an ideal solution when high performance computing is required in extreme environments. The Eagle is based on Intel’s 9th Generation Xeon-E processor which features 6 cores and Hyper-Threading. It includes high speed SSD storage (NVMe) and up to 32GB of error-correcting RAM.
• 2GHz Intel Xeon E processor
• Dual Mini DP++ outputs display outputs
• 16GB or 32GB DDR5 DRAM
• 2x Gbit Ethernet interfaces, 2x COM ports; 2x USB 3.1/2.0 ports, 4x USB 2.0 ports, 8x TTL I/O lines 3.3V, I2C
• PC/104 format mounting points
• -40°C to +85°C operation
• MIL-STD-202G qualified for high shock and vibration
• Size: 90mm × 96mm × 37 mm
Eagle (EPU-5120) datasheet
PC/104 Embedded Computer Sports 9th Gen i3 or Xeon-E
VersaLogic’s Sabertooth (EPMe-51) is a high-performance embedded computer with Xeon-E and 9th generation Intel Core processors, 3-Bank Type 1 expansion por, and error-correcting memory. The board Includes fast on-board NVMe SSD storage, TPM 2.0 security, and up to 32 GB ECC RAM. Opportunities exist for a pre-release board evaluation.
• High performance 9th generation Coffee Lake processor options
• Hex-core Xeon-E or quad-core i3 versions
• Up to 32 GB ECC RAM
• 3-bank expansion
• PCIe x16 Gen 3 expansion
• High speed on-board storage
• 128GB NVMe fast read/write SSD storage
• TPM 2.0 security
Sabertooth (EPMe-51) datasheet
Low Power PC/104-Plus SBC has Rich I/O
Winsystems’ PPM-C412 is a PC/104- Plus form factor SBC featuring the latest generation DMP Vortex86DX3 SoC processor. Its small size, low power, rugged design and extended operational temperature make it well suited for industrial IoT applications and embedded systems in the industrial control, transportation, Mil/COTS and energy markets.
• Low Power 1 GHz DMP Vortex86DX3 processor (dual core)
• PC/104-Plus form factor
• 2 GB DDR3-LV System RAM
• 4x USB 2.0 ports, 4x serial ports, Dual Ethernet
• CompactFlash, SATA
• Dual video output (VGA, LVDS with digital backlight dimmer)
• -40°C to +85°C temperature operation
Jeff served as Editor-in-Chief for both LinuxGizmos.com and its sister publication, Circuit Cellar magazine 6/2017—3/2022. In nearly three decades of covering the embedded electronics and computing industry, Jeff has also held senior editorial positions at EE Times, Computer Design, Electronic Design, Embedded Systems Development, and COTS Journal. His knowledge spans a broad range of electronics and computing topics, including CPUs, MCUs, memory, storage, graphics, power supplies, software development, and real-time OSes.