Apalis iMX6 Issue Tracker

Description: These errata are actually NXP errata affecting all i.MX and Vybrid processors. There are two issues in the boot ROM when using the processors in a security-enabled configuration (SEC_CONFIG[1] eFUSE is programmed). By default, this fuse is not programmed on Toradex modules. Customers not fusing this setting are therefore not affected by these issues. Customers using the security-enabled configuration are affected by these issues. More information can be found in the respective NXP errata documents: https://docs.toradex.com/104705-err010872-secure-boot-vulnerability-erratum-preliminary-rev0.pdf https://docs.toradex.com/104706-err010873-secure-boot-vulnerability-erratum-preliminary-rev0.pdf

Workaround: Please refer to the documents mentioned above for workarounds.

Customer Impact: If voltage is applied to ADC_AD1 input during boot, the ADC inputs and the touch interface may not work as the STMPE811 is not accessible on the I2C bus.

Description: The STMPE811 ADC and touch controller IC uses the IN0_GPIO1 pin for strapping between I2C and SPI mode. If the pin is high during the power-up of the controller, the chip gets misconfigured as an SPI device. In this case, the chip cannot be accessed over the I2C mode and is unavailable. The IN0_GPIO1 is used as ADC_AD1 input of the module (edge connector pin 307). A voltage applied to the analog input ADC_AD1 during the module's power-up can cause the ADC and touch controller to be strapped wrongly and therefore not accessible. The module features a circuit that pulls down the ADC_AD1 input during the reset state to prevent false strappings. However, this circuit may not work correctly if there is extensive backfeeding to the module. The best prevention is not applying any voltage to the ADC_AD1 input while the module is not powered.

Workaround: Ensure that there is no voltage applied to the ADC_AD1 input until the module booted. Use any of the other ADC inputs instead.

Customer Impact: Depending on the carrier board and the amount of backfeeding, the POWER_ENABLE_MOCI might not go low enough to turn off the peripheral voltage rails in the shutdown state.

Description: The POWER_ENABLE_MOCI signal is intended to be used for switching the peripheral voltage rails on the carrier board, like the 5V_SW and 3.3V_SW on the Ixora. Depending on the amount of backfeeding over the interface signals from the carrier board to the Apalis iMX6 module, the POWER_ENABLE_MOCI signal can remain between 1.0V and 1.4V in module shutdown. Depending on the carrier board circuit, this can be too high for turning off the peripheral voltage rails. For example, on the Ixora V1.2, a different buck converter for the 5V_SW is used than on the previous versions. The threshold voltage for the enable signal is lower on the new buck converter. Depending on the backfeeding level, the 5V_SW buck converter does not get disabled in the shutdown state. The Ixora V1.0 and V1.1 are not affected by this issue since they have been using a different buck converter with a higher threshold.

Workaround: Add a circuit to the carrier board for increasing the POWER_ENABLE_MOCI threshold voltage to between 2.0V and 2.5V. This could be achieved by adding a comparator or similar circuit. Such a solution is implemented in the V1.3 revision of the Ixora. A simple voltage divider added to the POWER_ENABLE_MOCI signal can shift the voltage levels. Important: make sure that the minimum input voltage for enabling the buck converter is still guaranteed. With the AOZ2260 buck converter (which is used on Ixora V1.2), a 10k/10k voltage divider can be a suitable option. For patching such a divider, replace R15 with a 10k 0603 resistor and add another 10k resistor from the PMIC_EN_5V signal to the ground.