Colibri iMX8X

Customer Impact: Triggering Recovery Mode on the SoM takes long or the SoM does not go into Recovery Mode.

Description: In some cases, the recovery button of carrier boards needs to be pressed for 6-10s after powering up the SoM to get it into Recovery Mode. In other cases, the SoM does not go into recovery mode at all, even after the 6-10s period has elapsed. The issue is caused by the combination of the NXP i.MX8X SoC's boot ROM code and the behavior of the USB interface of the host computer the USB OTG port of the carrier board is connected to. On the SoC side, at power-up, a boot monitor timer is initialized. During USB enumeration in serial download mode, the host side may enumerate multiple times until enumeration succeeds. The enumeration retries take time and result in a delayed entry into Recovery Mode. In some other cases, the maximum number of enumeration retries may get exceeded, which results in an enumeration failure. Under corner conditions, the ROM code may not be able to refresh the boot monitor timer due to the behavior of the USB host, causing a device system reset.

Workaround: In general, changing to a different host is the most effective way to avoid the issues. NXP may potentially fix this issue in the future.

Customer Impact: The HiFi 4 feature is not going to be available and supported in future hardware versions of the SoM, therefore customer applications potentially leveraging the feature are not going to be compatible with those future SoM hardware versions.

Description: The HiFi 4 DSP feature is no longer going to be featured and supported in future hardware versions of this product. Even though some current product versions may theoretically feature the IP in question, to avoid having compatibility issues in the future, please don't use the feature.

Workaround: None.

Customer Impact: If the second Ethernet port is used in the RGMII mode, the I/O voltage of 3.3V is not compliant with the specifications of NXP. Using the module pins as RMII or any other alternate function is not affected.

Description: According to the NXP datasheet for the i.MX 8X SoC, the I/O voltage of the RGMII interface is limited to 1.8V and 2.5V. The RGMII signals of the second Ethernet port is available as alternate functions of the RGB LCD interface. On the Colibri iMX8X, the I/O voltage of these signals is fixed to 3.3V. The maximum voltage of the pins itself is not violated. If the edge connector pins are used for any other function (e.g. RGB LCD or GPIO), the I/O voltage is fully compliant. Even using the pins as RMII for 100Mb/s Ethernet is fully compliant. Only when using the interface pins as RGMII, the I/O voltage is not compliant with the NXP specifications. No physical damage is expected when using the signals as RGMII with 3.3V I/O voltage since the actual SoC pins are rated for an absolute maximum voltage of 3.6V. However, the timing might not be compliant with the RGMII specifications.

Workaround: Use the second Ethernet port as RMII instead of RGMII. However, this limits the maximum interface speed to 100Mb/s (Fast Ethernet). RGMII would allow transfer rates up to 1Gb/s (Gigabit Ethernet).