VertiCal, a universal calibration system for eSys high performance 32-bit PowerPC microcontrollers; test challenges & solution

VertiCal is a calibration system for eSys, a family of 32-bit automotive microcontrollers based on the PowerPC architecture. To utilize the calibration system, a common scale package among the derivatives is required and a table of universal pin locations including the calibration pins is properly defined. However, the inclusion of the calibration pins has induced an uncommon structure where two balls in the package are sharing a pad on the die. This structure has created some test challenges. This paper discusses in detail the problem, followed by approaches in analysis and experimental results.