Board Bring Up

Question 1

What are the basic steps for “bringing up” a board?

Answer 1

1) Visual Inspection
2) Power Supply Tests
3) Reset and Clock Circuit Testing
4) Microprocessor interface Testing
5) Software Loading
6) Peripheral Circuit Checking
7) System Level Checking

Question 2

Describe the visual inspection step.

Answer 2

• CONTINUITY
• XRAYS
  Inspect all components for good soldering, proper orientation, and correct values.
• Check for SHORTS or OPENS
• Ensure JUMPERS are in the right place.

Question 3

Describe the power supply test step.

Answer 3

• Apply power (use a CURRENT LIMITER)
• Monitor the input current and ensure it doesn’t exceed design expectations
• Check voltages of power supply and other test points on board to see if voltages are what you expect.
• Check the power pins at all active devices

Question 4

Describe Reset and Clock Circuit test step.

Answer 4

• Check functionality of reset circuit on board.
• Trigger the reset by powering up and down (or using a pushbutton/switch if setup that way).
• Check that the reset waveforms are within the specs of the devices being reset.
• Check RISE and FALL times to be sure they have correct shape.
• Check that clocks are oscillating at right FREQUENCY

Question 5

Describe the microprocessor interface test step

Answer 5

• When you have a microprocessor on your board, sometimes upon booting up they will immediately start getting accessing memory from ROM. Therefore, verify that the the interfaces are within specifications:
• Timing and signal levels
• Use a hardware debugger to check pins on processor to ensure they are acting properly.
• Remember! At each step you are ensuring that the HARDWARE is working properly, so you can rely on it when working on the software.

Question 6

Describe the software loading test step.

Answer 6

• Create a very simple software program to run on the board.
• Write software to exercise the various interfaces, one step at a time.
• Software should allow for controlling all interfaces.
• Use a MONITOR program that includes:
  >Polled serial I/O
  >RAM tests
  >Simple commands to read and write to memory
  >Test commands for more complicated things
  > Test driver software running on a host PC can drive the monitor program to carry out some testing.

Question 7

Describe the peripheral circuit test step.

Answer 7

• More serious testing. Test that each external interface works.
• Have a checklist of things to check will help

Question 8

Describe the system level check test step.

Answer 8

• This is when you actually start connecting your sensors and actuators and testing them.
• Performance testing, etc.
• Probably the final step.