AM263P4-Q1: AM263P4-SIP_Q1, 2 HW Design questions.

Any feedback?

Rio Chan said:

Q1. According to the datasheet, SAFETY_ERRORn should be connected to VSS. However, the demo circuit shows it is pulled high to 3.3V, as shown in the figure below?

The datasheet's Pin Connectivity Requirements table states:

"This pin must be connected to ground (VSS) through a separate external pull resistor to make sure the pin is held to a valid logic low level if a PCB signal trace is connected and not actively driven by an attached device. The internal pull-down can be used to hold a valid logic low level if no PCB signal trace is connected to the ball."

Key context: SAFETY_ERRORn is actively driven by the device — the Error Signaling Module (ESM) aggregates safety-related events across the SoC and outputs an error signal on this pin. This is consistent with it being an open-drain, active-low output.

The VSS pull-down requirement in the datasheet applies to the scenario where the pin is not actively used/driven (i.e., tied off to a safe default). When SAFETY_ERRORn is used for its intended function — signaling safety errors — a pull-up to 3.3V (as shown in the Control Card demo) is the standard way to implement an open-drain active-low status output: the pin reads high during normal operation and is pulled low by the device when an ESM error is asserted.

Rio Chan said:

Q2. According to the datasheet, the T4 PIN should be connected to VSS. However, the demo circuit shows it is directly connected to 1.2V, as shown in the figure below? 

This looks to be a error, let me doiuble confirm with HW expert