In specific cases, robust system design requires the design of multiple boards that are interconnected to form a complete functional system. Such multi-board design creates an additional layer of design complexity, and as a result, an additional layer of complexity in the design-debugging process.
It is important to make the distinction that system-level design debugging is NOT equivalent to multiple single-board design debugging.
Here’s a very simple example to clarify the point:
Below is a 2-board system with board 1 powering the main board. Our main board is expecting a 5V input, which is also the input specification for board 1.
Both board 1 and main board have been debugged and found bug-free. Yet, the multi-board system has a bug that can NOT be detected when each board is debugged individually and not in the context of a system:
In this case, when the boards are inspected by BQR’s fiXtress® as a complete system we find that the voltage drop across inductor L1 causes P5V0_OUT to be 4.2V rather than the expect 5V. Therefore, the main board is underpowered and will not turn on, causing the entire system to malfunction.
Some of the common challenges encountered when designing a multi-board system include unverified connectivity between boards, no checks on connectivity specifications compliance, and errors caused by different sub-contractors / internal teams for different boards.
fiXtress design debugger is the perfect tool to resolve such issues checking for hidden schematic (logic) and electrical design errors in multi board systems.
fiXtress automates the debug process, reduces the number and length of integration debug cycles, creates uniformity of multi-board verification simulation and analysis method and results, increases operational confidence, and assures full and documented compliance with requirements / specifications.
To recap, multiple board integration reveals an additional layer of possible design / reliability issues. A system must be simulated, analyzed, and debugged first for each board, and then at the system level (integrated).