Hardware design review

Background

RidgeRun is a software company. Yet often customers ask us to review their schematic with the general direction being "Will this work with your software?" It is very expensive for RidgeRun to debug hardware design issues. We assume the hardware is right and if there is a problem, it must be in the software. Only after we eliminate all the possible software concerns do we focus on demonstrating the problem is in the hardware.

To help RidgeRun internally do a better job of reviewing schematics, I jotted down some notes. If you have suggestions, please pass them along to support@ridgerun.com.

High level

• Verify each of the I/O chips connected to the SoC has a Linux driver.

Signal level

• Is there a way to connect a scope to the signal either though
  • a test point
  • a resistor or other component

Pinmuxing

• For each pin on the SoC, document the correct pinmux setting.

GIO signals

• For each GIO signal, document
  • if it is input/output,
  • if it needs to cause a CPU interrupt
  • if a pull up or pull down resistor needs to be enabled (or connected)
  • if it is an output, should it be initialized high or low

• Document use

I2C bus signals

• Document which I2C address is used for each I2C chip.