An AI Engine event gives information about the system at a specific instant in time. An event that is associated with a timestamp, type and set of data values is referred to as a payload. The interpretation of the payload depends on the type of the event. A timestamp allows ordering of events, computation of causality relationships, and implementation of verifiers on a sequence of events.
For event modeling purposes, the key modules of the AI Engine array are processor, DMA, lock modules, memory, and I/O streams. Each module can be viewed as an event generator/responder. Each module receives an event and responds to the event. As a response, new events could be generated. Events are classified based on the generator of the events. The timestamp is not mentioned explicitly in the event definitions. Each event is described with a payload, which is a couple of values associated with the event. Each AI Engine, memory, DMA, or lock is addressable by a two-dimensional index <col, row>, which is the column and row index in the AI Engine array. Some of the AI Engine events are shown in the following tables.
Events generated by the AI Engine and their corresponding IDs are listed in the following table.
| Event Number | Event Name | Comment |
|---|---|---|
| 22 | Group Core Stall | Any or all the events from event number 23 to 31 can trigger this event |
| 23 | Memory Stall | Event generated when core gets stalled due to memory conflict |
| 24 | Stream Stall | Event generated when core gets stalled either due to no data at input or due to backpressure on the stream output from core |
| 25 | Cascade Stall | Event generated when core gets stalled either due to no data at Input or due to backpressure on the stream output from core |
| 26 | Lock Stall | Event generated when core gets stalled due to lock being acquired already |
| 28 | Active | Event generated when core changes state from disabled to active |
| 32 | Group Core Program Flow | Any or all the events from event number 33 to 45 can trigger this event |
| 37 | Instr Vector | Event generated when AI Engine core executes a “vector” instruction |
| 38 | Instr Load | Event generated when AI Engine core executes a “load” instruction |
| 39 | Instr Store | Event generated when AI Engine core executes a “store” instruction |
| 40 | Instr Stream Get | Event generated when AI Engine core executes a “read from stream” instruction |
| 41 | Instr Stream Put | Event generated when AI Engine core executes a “write to stream” instruction |
| 42 | Instr Cascade Get | Event generated when AI Engine core executes a “read from cascade stream” instruction |
| 43 | Instr Cascade Put | Event generated when AI Engine core executes a “write to cascade stream” instruction |
| 50 | FP Overflow | Event generated when floating point overflow exception flag bit gets set |
| 51 | FP Underflow | Event generated when floating point underflow exception flag bit gets set |
| 52 | FP Invalid | Event generated when floating point invalid exception flag bit gets set |
| 53 | FP Div by Zero | Event generated when floating point div by zero exception flag bit gets set |
Events generated by the AI Engine memory module and their corresponding IDs are listed in the following table.
| Event Number | Event Name | Comment |
|---|---|---|
| 20 | Group DMA Activity | Any or all the events from event number 21 to 40 can trigger this event |
| 25 | DMA S2MM 0 finished packet | Event generated when S2MM channel 0 finishes the transfer of a DMA Packet |
| 26 | DMA S2MM 1 finished packet | Event generated when S2MM channel 1 finishes the transfer of a DMA Packet |
| 27 | DMA MM2S 0 finished packet | Event generated when MM2S channel 0 finishes the transfer of a DMA Packet |
| 28 | DMA MM2S 0 finished packet | Event generated when MM2S channel 1 finishes the transfer of a DMA Packet |
| 33 | DMA S2MM 0 stalled lock acquire | Event generated when S2MM channel 0 is stalled on lock acquire |
| 34 | DMA S2MM 1 stalled lock acquire | Event generated when S2MM channel 1 is stalled on lock acquire |
| 35 | DMA MM2S 0 stalled lock acquire | Event generated when MM2S channel 0 is stalled on lock acquire |
| 36 | DMA MM2S 1 stalled lock acquire | Event generated when MM2S channel 1 is stalled on lock acquire |
| 43 | Group Lock | Any or all the events from event number 44 to 75 can trigger this event |
| 76 | Group Memory Conflict | Any or all the events from event number 77 to 84 can trigger this event |
| 86 | Group Errors | Any or all the events from event number 87 to 100 can trigger this event |
Events generated by the AI Engine interface and their corresponding IDs are listed in the following table.
| Event Number | Event Name | Comment |
|---|---|---|
| 74 | Port_Idle_0 | Event generated when specified PLIO port is
Idle. Any of the Master or Slave ports for AI Engine Tile
Stream Switch can be monitored for Port Idle condition. The
|
| 75 | Port_Running_0 | Event generated when specified PLIO port is
Running. Any of the Master or Slave ports for AI Engine Tile
Stream Switch can be monitored for Port running condition. The
|
| 76 | Port_Stalled_0 | Event generated when specified PLIO port is
Stalled. Any of the Master or Slave ports for AI Engine Tile
Stream Switch can be monitored for Port stalled condition. The
|
| 77 | Port_TLAST_0 | Event generated when specified PLIO port is
transmitting a TLAST signal. Any of the Master or Slave ports for
AI Engine Tile Stream Switch can be monitored for Port TLAST
condition. The
|