Maxim MAXQ622 Errata Sheet

About this manual

The document provides a list of errata that affect the MAXQ622 B1 revision, describing the observed behavior and recommended work‑arounds for each issue. It covers problems ranging from watchdog timer resets to flash programming failures, memory protection faults, power‑supply anomalies, and instruction‑execution errors.

Each entry includes a brief description of the symptom, the conditions under which it occurs, and a practical mitigation strategy that designers can apply to avoid or correct the problem in their designs.

What's inside

• Watchdog timer reset locks IC in reset
• Flash program/erase operations fail in clock‑divided mode
• System code inadvertently erased
• Memory protection fault asserted
• Vpp power supply oscillates on USB disconnect
• Unreliable power‑up when only Vpp is applied
• High Vpp standby current
• Push instruction causes code execution error
• Interrupt priority feature can cause incorrect processing
• I2C peripheral does not function correctly

Frequently asked questions

What happens when the watchdog timer reset occurs while the internal oscillator is in divide‑by‑4 mode?

The watchdog timer reset locks the IC in reset, requiring a power cycle to recover.

How can flash programming and erase operations be made reliable in clock‑divided modes?

Set the system clock to divide‑by‑1 (non‑divided) mode before invoking flash write or erase functions.

What is the recommended workaround for the memory protection fault when debugging in upper memory?

Avoid using memory protection or avoid debugging in the upper memory region.

How can the high standby current on Vpp be prevented when USB is connected?

Set the FRCVDD control to logic‑low under the condition where Vpp < Vpps‑0.5 V.