It wasn't too long ago that the terms "AMC" and "Performance" were mutually exclusive. Trenton has long focused on designing and building, full-size, PICMG 1.0 and 1.3 high-performance single board computers and system host boards. So what has changed to expand Trenton's focus beyond its core engineering expertise?
The introduction of the new Penryn-class of dual-core, small form factor (SFF) processors and the small form factor Intel GS45 Express chipset brings a new and unique combination of performance, size and thermal efficiencies to AMC card designs. There are a few design challenges that we came across in developing the Trenton MCP6792 AMC Processor card that I would like to share with you.
1. You need a really, really good board house! -- Even though the size of the processor and chipset are each only 22mm square, the density of the components pin arrangement and memory interface rules are going to drive you to a bare board design of 8, 10, 12 or more layers. The available AMC real estate is going to require a fair number of blind and buried vias in the bare board design. To illustrate the card density point, here is our factory assembly drawing for the topside of the Trenton MCP6792 card:
2. You need an even better manufacturing facility!! - To paraphrase the real estate agents, the most important aspect of a high performance AMC card is "component density, component density and component density." Trenton's manufacturing facility has the expertise needed to build repeatable and reliable small form factor card designs because of the accuracy of our pick and place card assembly machines. You're going to need to use some extremely small components in your card design so the required repeat accuracy of your assembly machine becomes very critical. You will also need to place a large number of components on the bottom side of the AMC without violating any clearance specifications. Here is our factory assembly drawing for the bottom side of the Trenton MCP6792 card:
3. The various AMC, MicroTCA and AdvancedTCA specifications are going to drive you toward a soldered-down processor design. -- This may present you with some future product mix/availability limitations.
4. The SFF chipset offers more PCI Express routing options to the backplane than are currently supported by the PICMG MicroTCA and AdvancedTCA specifications. - Don't let this specification limitation hold you back in your AMC design. We're figuring that the specifications are going to be updated at some point, so you ought to design in a way to take advantage of all the available PCIe routing options out of the chipset.
5. TPM and IPMI are key requirements to implement in many AMC applications. - An external TPM will achieve full compliance with version 1.2 of the Trusted Computing Group specification. We implemented an external TPM on the AMC because we took this approach in other Trenton board designs and it meets the full compliance required in many military and aerospace applications. The chipset has a feature called Intel Trusted Execution Technology or Intel TXT capability that provides a level of platform security and protection that may be acceptable in most applications. IPMI is a must in many telecommunication applications and we implemented some hardware and firmware IPMI features that will be useful in non-telecommunication applications.
Did any of you experience similar AMC design challenges? If so, I'm sure the rest of the design community would be interested in hearing about your experiences. Perhaps you could post a completely different list of challenges?
In a future blog on small form factor product designs, I will share with you some of our benchmark data on the Trenton AMC6792 AMC Processor card featuring the Intel Core 2 Duo SL9400 processor and the card's SFF Intel GS45 Express chipset.