SPRACN0F October 2021 – March 2023 F29H850TU , F29H859TU-Q1 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320F28384D , TMS320F28384S , TMS320F28386D , TMS320F28386S , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1
The communication interfaces between devices in decentralized architectures can vary in network topology, number of node devices, physical distance between the nodes, and more. Devices can also have slight deviations in their local clock during operation due to manufacturing uncertainties, thermal effects, aging, and so forth. Regardless of these variations it is often important for specific events to occur at the same time across all devices in a system, such as ADC start of conversions or rising/falling edges of PWM signals. Synchronous events between C2000 devices can be implemented using the FSI module and custom CLB logic.
With the goal of synchronizing equivalent PWM signals across devices as an example, the implementation can be explored further and is depicted in #FIG_JC5_KYJ_DRB. The lead device in a network will periodically send PWM sync requests, as FSI PING frames, to all node devices. In a daisy-chain topology each node device will forward the sync request frame to the next device in the chain. When a node device receives the sync request frame the CLB module will internally route the Ping Packet Received (PING_PKT_RCVD) signal from the FSI RX module through a configurable delay before connecting to the ePWM’s EPWMSYNCIN signal. The configurable delay would be calibrated such that all node device’s EPWMSYNCIN signals get triggered at the same time and match the lead device’s TBCTR equals zero or PRD event. The implementation is completely hardware based and does not require software intervention after initialization. In a daisy-chain topology, nodes at the beginning of the chain will need a longer configurable delay compared to those at the end, since it takes time for the sync request frame to reach all devices. This will ensure the lead and all node devices PWM signals remain in-sync during operation.
For a more detailed explanation of the event synchronization over FSI along with test results, see the Event Synchronization Over FSI section of the Using the Fast Serial Interface (FSI) With Multiple Devices in an Application .