The Truesilicon's PMBus Master Controller IP is a programmable digital power management interface designed to enable communication between a host processor and external PMBus-compliant power management devices. The controller integrates an AMBA APB slave interface for software configuration with a PMBus Master interface based on the SMBus/I²C physical layer. Through the APB interface, software can configure PMBus transactions, program target device addresses and commands, initiate data transfers, and monitor the status of communication using memory-mapped registers. 

The controller includes an internal PMBus protocol engine that automatically handles all low-level bus operations, including generation of START, Repeated START, STOP, ACK, and NACK conditions, target addressing, and data transmission over the SCL and SDA lines. It supports standard PMBus transaction types such as byte, word, and block read/write operations, enabling software to configure and monitor multiple PMBus-compatible devices including PMICs, digital power supplies, DC-DC converters, and voltage regulators.

To ensure reliable communication, the controller supports programmable bus timing, clock stretching, optional Packet Error Checking (PEC) using CRC-8, and SMBALERT# monitoring for immediate fault notification from connected PMBus target devices. Status and interrupt registers provide information on transaction completion, bus busy conditions, NACK reception, timeout detection, and communication errors, allowing both polling-based and interrupt-driven software operation. 

Designed for seamless integration into APB-based SoCs, the PMBus Master Controller IP provides a standardized and efficient solution for digital power management. By combining a processor-friendly APB interface with a standards-compliant PMBus master, the IP simplifies configuration, monitoring, diagnostics, and control of multiple power management devices, making it well suited for server platforms, networking equipment, industrial automation, storage systems, and other embedded applications requiring centralized power management.

Figure 1 illustrates the high-level architecture of the PMBus Master Controller IP. The APB interface provides software access to the configuration and status registers, which control the PMBus Protocol Engine. The Protocol Engine manages PMBus transactions through the Clock Generator and PMBus PHY, while the Interrupt Controller collects status and error events from the internal blocks and generates a consolidated interrupt to the host processor.