> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

#  Introduction

This guide helps you bring up the CQ2390/IQ2390/CQ2390/IQ2390S MCU subsystem, run representative sample applications, validate core interfaces, and trace issues during integration. The structure is intentionally task-first so readers can hit a working path early and then move into reference detail.

**1.1 What you can build using the MCU**

The MCU subsystem is a low-power, event-driven subsystem based on a single SiFive E61 RISC-V core. It offloads always-on, latency-sensitive, and policy-driven work from higher-level processors so the host wakes only when escalation is required. The source material explicitly supports always-on sensing, local pre-processing, timer scheduling, policy-controlled host notification, UART, I2C, I3C, wake handling, and optional QUP plus GPI transfer support.

■ Console and debug logging over a UART path.

■ Sensor reads over I2C or I3C with native Zephyr-style APIs

■ GPIO interrupt and wake handling.

■ Low-power entry and wake validation.

■ Higher-throughput transfer handling through QUP with optional GPI.

**1.2 Technical assistance**

For assistance or clarification on information in this document, go to [https://www.qualcomm.com/support](https://www.qualcomm.com/support).