MIPI SPMI Protocol Support

MIPI SPMI (System Power Management Interface) is a two-wire serial interface developed by the MIPI Alliance for communication between application processors and power management ICs (PMICs) in mobile devices. SPMI uses SCLK and SDATA lines operating at up to 26 MHz, providing a high-speed, low-pin-count connection for controlling voltage regulators, battery chargers, GPIO expanders, ADCs, and other power management functions integrated into the PMIC. The protocol supports up to 16 master IDs and 16 slave IDs on a single bus, with transaction types including register write, register read, extended register write/read (for larger address spaces), authentication, and reset commands. SPMI defines a master arbitration mechanism allowing multiple processors to share the same PMIC bus. Each transaction includes a sequence start condition, slave address, command frame, and optional data frames with parity checking. SPMI is found in virtually every modern smartphone, tablet, and wearable device, as well as in automotive and IoT platforms that use mobile-derived SoCs. Protocol analysis for SPMI is essential because PMIC configuration directly affects system power delivery, battery life, and thermal management. Engineers need to verify voltage regulator settings, debug power sequencing issues, validate PMIC firmware updates, and troubleshoot system stability problems that often trace back to incorrect SPMI register configurations or timing violations.