Expressing the standard

Embedding computers and sensors into everything is the norm, and solutions are becoming more varied every day.

In the beginning, most processor chip manufacturers focused on increasing computational power for the desktop market. As the world became more mobile, chip manufacturers first slimmed down desktop processors for the laptop market, then eventually moved to optimizing power-to-performance ratios by designing processors from the ground up. Handheld mobile computers – PDAs, smart phones, appliances, and the like – also began to accelerate in use. Today, non-x86 as well as x86 architectures compete for this valuable market space.

This trend has pushed the envelope in designing extremely low-power, high-performance, x86-based processors. Computer control and information gathering and processing have changed not only the way we look at things, but also the way we live. Embedding computers and sensors into everything is the norm, and solutions are becoming more varied every day.

Custom platforms serve a purpose but can restrict OEMs, making them unable to adapt. For those requiring versatility, it is important to choose platforms that are well established as standards while providing paths to future advancements.

For more than 15 years, the stackable PC/104 architecture that is embodied in PC/104, PC/104-Plus, PCI/104-Express, PCI-104, EBX, EPIC, and the recently released EPIC Express has thrived and gained recognition throughout the world as one of the few de facto embedded standards. The architecture is based on well-defined full PC bus architectures, form factors, common mounting holes, and bus placements.

Implementing PC bus structures like ISA, PCI, and PCI Express allows users to develop common drivers and reuse add-on modules as CPUs evolve in class.

The newest stackable PC/104 bus has continued this philosophy by incorporating the PCI Express bus. The resultant stackable PCI Express connector provides four x1 links and a x16 link that can be used as two x4, two x8, or two SDVO links. Unique signaling automatically detects stacking direction and video card type, if a video add-on module is being used. The bus also offers power management, SMBus, and additional high-speed differential lines. Ground pins surrounding differential pairs and power rails embedded in the connector ensure maximum power delivery for the stack and additional devices if necessary.

Keeping an eye on continuity among the Consortium's form factors, this new stackable PCI connector has been placed on all its form factors, which has resulted in the adoption of PCI/104-Express V1.0 and EPIC and EPIC Express V3.0, with EBX and EBX Express V3.0 currently undergoing the adoption process.

The simplicity of using a single, rugged, high-speed connector solution maximizes growth in the add-on module ecosystem, reduces manufacturing alignment issues, and eliminates multiple module configurations.

As IC manufacturers continue on their path to develop smaller and smaller processor and peripheral chip solutions using less power with more functionality, designers can achieve greater expandability if desired. Do all solutions require the full bandwidth the connector provides? The answer is no, but having the option gives OEMs more flexibility.

A vast array of PCI Express chips has hit the market already, and the number is increasing every day. These chips utilize anything from PCI Express x1 links to x16 links. For those PCI devices that have not yet migrated, PCI Express-to-PCI bridges can not only make use of those technologies but also help increase the number of devices available with its increased bandwidth. If more capability is needed, switch technology enables designers to realize additional PCI Express links of various sizes, PCI Express over cable, and more.

Outside the Consortium, the success of the PC/104 standard has prompted designers to incorporate these bus architectures onto a number of non-Consortium controlled form factors and custom designs so that they can enhance functionality without having to become experts in designing that functionality.

PC/104 stackable buses and versatile form factors have created an embedded ecosystem that caters to the greenest of green as well as the highest of performance and power consumption. A vast selection of interchangeable modules spanning an enormous range of applications has evolved, enabling designers and end users to create next-generation upgrades and revolutionary application-specific solutions.

PC/104 Consortium