SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
The PMBus module supports the Group Command protocol. The Group Command (Figure 35-14) protocol is used to send commands to more than one device within the same message. When devices on the bus detect the stop condition at the conclusion of the Group Command message, the received commands are executed concurrently. Following address and command acknowledgment, the module provides a data ready interrupt upon detection of 4 data bytes or the transmission of a repeated start on the bus. The firmware must wait for the EOM interrupt before processing the received command, as required by the use of the Group Command message.
For Group Commands, the data ready bit is set as soon as the repeated start is received. The data can then be read into memory. But the data must not be acted upon until the EOM bit is set, which occurs when all of the messages have been received. Other than this delayed EOM, there is no difference for the slave firmware in receiving a Group Command than any other write message.