Standard Multi-Board Verification
The standard method for interfacing several boards correctly is by using ICD (Interface Control Document) where all inputs and outputs of each board are defined. Ideally the ICD should be well defined, and each board should comply with its own ICD. Unfortunately, this is often not the case. Following are some typical examples of issues that BQR engineers encountered while analyzing customer multi-board designs:
- ICD may not be well defined, this causes confusion between the different groups that design the separate boards.
Until recently there was no standard for ICDs. BQR’s CTO Yizhak Bot led the effort to formulate such a standard for the aerospace industry [1].
- A main power supply provides power to several boards. While the power is sufficient for each separate board, the power may be insufficient for all boards together.
- I2C communication requires a pull-up resistor, but each board designer believes that the other board includes the pull-up resistor, and eventually no resistor is implemented in the system design.
Simulation based Multi-Board Verification
BQR’s CircuitHawk software has the unique capability to conduct circuit stress simulation over large multi-board designs. Rather than depending on ICDs, the simulation verifies the actual integrated detailed design. In this way many design errors are found at an early stage, saving time and money.
References
[1] IEC-63238-1 Process management for avionics – Electronics design – Part 1: Electrical signal properties, naming conventions and interface control document (ICD)
