SMBus, PMBus, and I2C protocols are communication protocols used for inter-device communication in embedded systems. While these protocols are similar in many ways, including their physical layer, there are also multiple differences in how they operate and where they are used.

I am trying to use the Promira Serial Platform to talk to an I2C device.  I am following the instructions in the Promira Serial Platform Quick Start Guide, yet I cannot successfully complete a master write.

SMBus was originally conceived by Intel in 1995 and was initially created as a communication protocol for Smart Batteries and other system and power management components. While developing hand-held and mobile devices, Intel determined there was a need to extend the functionality of their chipset and attach batteries to the system, while also limiting the number of the pins. Intel determined a low-speed serial bus such as I2C would meet this requirement. By utilizing I2C’s core operations, including device addressing, start and stop conditions, and collision detection and correction, and further modifying certain electrical characteristics to meet the battery requirements, SMBus was developed.

I am working with an I2C device that will be used for lengthy write and read transactions. There are multiple masters on this bus, any of which could send and start a command, thus taking ownership of the bus.