I am dealing with an issue where noise/some other factor is occasionally causing the nRPI_BOOT pin to appear low to the CM4 during boot, so the device attempts to boot from USB instead of the eMMC, meaning it never boots.
According to the datasheet, nRPI_BOOT is pulled up to 3.3V internally via a 10kohm resistor. However, when probing this pin with the CM4 on both my custom hardware and a Waveshare I/O board, that pin reads closer to 2.7V. My noise issue would be easier to mitigate without giving that pin a 0.6V "head start" to a low state.
Does anyone know why this pin's voltage might read so low, despite the internal 10k pullup?
According to the datasheet, nRPI_BOOT is pulled up to 3.3V internally via a 10kohm resistor. However, when probing this pin with the CM4 on both my custom hardware and a Waveshare I/O board, that pin reads closer to 2.7V. My noise issue would be easier to mitigate without giving that pin a 0.6V "head start" to a low state.
Does anyone know why this pin's voltage might read so low, despite the internal 10k pullup?
Statistics: Posted by bh1990 — Fri Feb 02, 2024 10:54 pm
