We are investigating defects on the board. Even though / PORST is always H input to MPC8270 on the board, pulses are periodically output from / HRST and / SRST and reset is applied. What are the possible causes? ・ The pulse width of / HRST is 16us, and / SRST is almost the same. ・ The pulse interval of / HRST is more than 10 seconds, and / SRST is almost the same. ・ The power supply and clock are normal. ・ There is one CPU on the board. ・ Softwarewatchdog is invalid ・ Checkstop has not occurred Thank you