RL78/F14 : Sporadic switching of Complimentary Pair Channels at same time

Background:

The B0-D0 pair is configured as complimentary with a deadband of 1usec (500nsec each side). The complimentary pair works fine overall

The complimentary is enabled/activated inside the PWM period completion ISR through TRDOER1 register.

The Duty value is loaded in buffered mode.The Duty is forcefully written 0 in PWM period Isr at the same instant when complimentary is activated.

Issue : sporadically both the channels turn ON for 2 usec (the instant is captured in the attached screenshot). Root cause of this issue is not known

Please find the attached screenshot of the waveforms captured.(Pink – slave channel : Yellow – master channel)