Other Parts Discussed in Thread: TPS3850
Hi,
We know during the first time burn the MCU firmware, we need to disable WD by setting SET0/1 by the MCU, but before the first time burn MCU, the MCU cannot control SET0/1, so we have to add a pull up resistor for SET0 and pull down resistor for SET1 as the default status to disable WD(This solution is my proposal for customer, if you have better one please let me know). The problem is, considering functional safety, if MCU fails in normal operation and its GPIOs are in tri-state, then SET0 and SET1 will be in the default state(Pull SET0 up to 1 and Pull SET1 down to 0), then disable the WD, then 3850 cannot watch and report the MCU has failed, so that 3850 cannot reset the MCU. Am I correct? Do you have any better idea or other device to solve this problem? Please contact me through wayne.liu@ti.com if you think our conversation is confidential. Thanks.
