Verdin iMX8M Plus Issue Tracker

Customer Impact: A sudden change in the computer module input voltage might involuntarily activate the CTRL_PWR_BTN_MICO# signal that, by default, will initiate the software shutdown or wake the system from the sleep state.

Description: The circuit used to generate the CTRL_PWR_BTN_MICO# on the computer module is affected by a hardware bug that could cause this signal to be triggered involuntarily by a fast change in the input voltage. The Voltage needs to increase immediately by at least by 0.9V to trigger the signal. The CTRL_PWR_BTN_MICO# allows the implementation of a power button behavior like the ones used on regular personal computers and smartphones. Short pressing the power button powers up the system from the “Module OFF” state or wakes the system from the sleep state. If the module is running, short pressing the power button generates a software interrupt. Depending on the operating system settings, this starts a software shutdown or opens a menu that lets the customer decide what to do.

Workaround: The best way to mitigate this issue is to configure the CTRL_PWR_BTN_MICO# differently in the software. If this is not possible and it is necessary to test the behavior of a module where this issue has been fixed, please contact the support team. Future versions of this product will have a different assembly option that will solve this bug completely.

Customer Impact: The Bluetooth solution is not accessible by the system as the host interface strapping signal of the Bluetooth solution is unintentionally influenced by a stitching capacitor on the SoM. This leaves the Bluetooth solution in the UART interface mode instead of SDIO.

Description: The signal used for strapping the HCI (Host Controller Interface) configuration of the Bluetooth solution at the time of powering up the SoM is also available on the Module-specific pin MSP_8 (#104) of the SoM edge connector. Module-specific pins feature stitching capacitors for providing current return paths for cases when those pins are being used for accommodating high-speed signals. The Verdin iMX8M Plus V1.0B configurations equipped with a Wi-Fi/Bluetooth solution feature one such capacitor (C210) on the MSP_8 signal. During powering up the system, the stitching capacitor is delaying the transition of the related signal to the intended state and thus results in a wrong configuration being strapped. Instead of SDIO mode, the host interface of the Bluetooth solution gets configured to UART mode. As a result, the Bluetooth solution is not accessible by the system.

Workaround: Remove the stitching capacitor C210 from the SoM. This makes the Bluetooth interface work in case the SoM is connected to a Dahlia V1.1A carrier board. If the SoM is connected to a Verdin Development Board V1.1A, then other stitching capacitors need to be removed from the carrier board as well. For more information, please refer to HAR-8342 in the Verdin Development Board errata. The issue will be resolved in future HW versions of these products.

Customer Impact: The optional master clock output of the CSI_1 interface (CSI_1_MCLK) is not usable. Most of the CSI camera modules supported by Toradex feature an on-board crystal/oscillator and thus do not require this clock for functioning properly.

Description: The Verdin pinout contains an optional master clock output for the CSI_1 interface. The SAI3_MCLK SoC pin is used for providing the optional Verdin camera interface master clock CSI_1_MCLK output. This signal is available on the module edge connector pin 91. The SoC pin can provide clock signals from the SAI3 and SAI5 audio interfaces. Therefore, a dummy audio driver with a dummy audio stream would be required for enabling the clock output. The current Toradex BSP does not support the CSI_1_MCLK option.

Workaround: Instead of using the CSI_1_MCLK, use an external crystal or oscillator for the camera. The i.MX 8M Plus SoC features two general-purpose clock outputs that can be used independently from the audio interfaces. Those clock signals are only available as alternate functions of other signal pins. Therefore, the clock signals are not compatible with other Verdin modules. If one of the general purposes clock outputs are used, adding an assembly option for using the CSI_1_MCLK pin is highly recommended. This ensures compatibility with existing and future versions of the Verdin iMX8M Plus and other Verdin modules.