Root Cause Analysis of Power Switch in Deadlock State using IEEE 1801 (UPF)
Sagar J. Patel, Sorabh Sachdeva, Siddhartha Jain · 2020
A root cause analysis of a power switch not coming out of OFF state is discussed with the application of IEEE 1801 (UPF), which is widely known industry standard power intent format. The learning is derived from one of SoCs from NXP Semiconductors and is presented in threefold manner. The first part of paper discusses the problem statement where during power-up sequence, power switch is stuck in deadlock state as its enable is driven by switchable (generated) supply. The second part explains root cause analysis carried out by performing various experiments in low power sign-off tools using IEEE 1801 and the third part describes enhancement in IEEE 1801 power intent writing style and sign-off methodology to mitigate such issues in future.