Ampro's EnCore is a CPU module in the truest sense of the word. While Ampro frequently refers to CoreModule CPUs as modules and promotes the use of CoreModule CPUs as pluggable into a custom logic board, CoreModule CPUs and other PC/104 CPUs all make design compromises which allow them to operate standalone.
These compromises, which are an inherent part of the PC/104 specification, include direct power supply connection and direct connection of utility and other I/O cables. It is these compromises, coupled with the very small size of the PC/104 form factor which has come to limit the amount of logic that can be included in a PC/104 CPU. Too much space is wasted on connectors - and the sheer size of the board limits the number of I/O lines the user can connect to it.
Ampro's EnCore is a module that has no direct I/O cable connections (except for one). It is designed to mount on a custom logic board (a baseboard) and all the I/Os are clustered onto three 44-pin connectors mounted on the bottom of the board. There are separate 10-pin connections for Ethernet and for power and ground. A separate 120-pin connector brings the PCI bus from the EnCore module to the baseboard. The PCI bus provides the basis for adding application-specific logic, in the form of PCI-bus compatible ICs.
EnCore modules are bigger than the CoreModules, but about half the size of an EBX board. While EnCore qualifies as a module based on its I/O interface, it is fabricated using standard PCB technology. Functionality-wise, EnCore looks like some of the so-called card PCs, but offers a much higher level of integration using the latest embedded technology (including 3D graphics, LCD support, Ethernet, sound, RAM and much more).
Finally, there is nothing inherent in the EnCore design that limits EnCore modules to Intel architecture processors. The ISA bus is gone. The sole bus interface is PCI. The I/O signals are those of standard peripheral devices. In fact, it is possible to build an EnCore baseboard which is completely CPU agnostic. As a result, it is far more than theoretically possible to remove a Pentium-based EnCore module from a baseboard and replace it with an EnCore module based on a RISC processor and have the hardware come up and run immediately.
Benefits
Most electronic products being built today (usually called embedded systems) use a single logic board (or at most two) to reduce cost. After all, a Compact PCI chassis would make our laser printer or telephone way too large and bulky. That logic board contains a microprocessor. When designing the logic to control the device, the design team must also design what is essentially a CPU subsystem, including memory interface, bus structure and fundamental peripheral devices. The designer just needs these to make things work - they are almost incidental to the key elements which will differentiate the product in the market. But this CPU subsystem is by far the most complicated and time-consuming part of the design. Those who have ever brought up a new CPU board from scratch will know about this. There is nothing worse than looking at a blank screen and working through cycle by cycle to figure out where it breaks. Modern CPUs, especially the integrated ones, are notoriously difficult to work with. It is hard to get a logic analyser probe on the internal die.
If you think bringing up new CPU hardware is fun, try getting an operating system to run on it. We have all seen the growing popularity of off-the-shelf realtime operating systems such as QNX, VxWorks and Linux. Once you get out of the x86 world, each operating system must have specialised start-up code written for that OS that runs from reset on the unique processor/peripheral combination involved. Producing this start-up like writing a BIOS from scratch. You will get some sample code from the CPU manufacturer or OS supplier, but you are really on your own here. This is very specialised work and very few individuals are experienced at this level. And they do not teach it in college any more (it is not C++ or Java - ask any new graduate if they have ever programmed in assembly language).
However, the real benefit of using an EnCore module as a CPU subsystem on a custom logic board is that one gets to skip these onerous steps. The CPU does not have to be brought up from scratch - it already works. And you do not have to port any operating software to it - it has already been done!
| Tel: | +27 12 493 0852 |
| Email: | [email protected] |
| www: | www.epd.co.za |
| Articles: | More information and articles about Electronic Products Design |
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version