Electronic – Linux/open-source program to open (OrCAD) schematics for BeagleBone

OrCAD does have a feature for automatically assigning designators in a hierarchical design.

Suppose, your design has following schematics (folders):

• Schematic1 has components C1 and R1
• Schematic2 also has components designated C1 and R1
• Schematic3 is a Top Block Diagram. It's set as a root. It's highest in the hierarchy. Hierarchical blocks for Schematic1 and Schematic2 are drawn on Schematic3. If some schematic is not drawn in the root*, then it's not in the hierarchy and OrCAD will not treat it as a part of the design.

* Or in one of the root's children. It's recursive. You get the idea.

Here are the steps for automatically assigning incremental designators:

1. Bring up the design window
2. In the design tree, click on the design itself. (It's the node, which contains all of the schematics.)
3. Menu: Tools -> Annotate...
4. Select Reset all part references to "?"
5. Click OK.
6. Open Schematic1 and Schematic2. Notice that designators became C? and R?. Go back to the design tree.
7. Again, menu: Tools -> Annotate...
8. Select Incremental Reference Update
9. Click OK.
10. You should have incremental designators throughout the design.

The processor on the BeagleBone is not a microcontroller, but rather a microprocessor (the Sitara AM3359 from Texas Instruments), which doesn't have non-volatile memory on the processor itself, but rather tries to load programs (such as an OS) into RAM via a communications interface (UART, USB, Ethernet) or from an external memory (FLash or memory card). The initialization/booting process for this processor is described in detail starting at page 4667 of the technical reference manual.

It seems the latter (booting from a memory device) is the case for the BeagleBone, which means you can "program" the BeagleBoard by changing the content of the on-board Flash (eMMC) or by forcing it to boot from the microSD card. It's not very clear from their documentation how easy or hard it is to create your own memory images (for SD card or the eMMC). I suspect it's not trivial.