SPMI uses a 4-bit Slave ID (SID). This limits the bus to 16 devices, keeping the address overhead small and transmission efficient.
When laying out an SPMI bus on a PCB:
In embedded Linux (Android kernels), SPMI is a standard subsystem. spmi interface
This guide provides the foundation for understanding, implementing, and debugging the SPMI interface in embedded systems. SPMI uses a 4-bit Slave ID (SID)
| Feature | I²C | SPMI | | :--- | :--- | :--- | | | General purpose sensors, RTC, EEPROMs. | Power management (PMICs), regulators. | | Speed | Up to 1 MHz (Fast Mode Plus). | Up to 26 MHz. | | Addressing | 7-bit or 10-bit. | 4-bit (up to 16 devices per bus). | | Handshake | No hardware flow control. | Supports "Handshake" and "Park" modes for flow control. | | Command Structure | Simple read/write. | Complex commands (Read, Write, Ext_Write, Ext_Read, Reset, Sleep). | | Power Efficiency | Good. | Optimized (features specific sleep/wake commands). | | | Speed | Up to 1 MHz (Fast Mode Plus)