AI Engine Options - 2023.1 English

The following options apply to the AI Engine compilation process.

constraints

Constraints (location, bounding box, etc.) can be specified using a JSON file. This option lets you specify one or more constraint files.

constraints=constraints.json

heapsize

Heap size (in bytes) used by each AI Engine

The stack, heap, and sync buffer (32 bytes, includes the graph run iteration number information) are allocated up to 32768 bytes of data memory. The default heap size is set to 1024 bytes. Before changing the heap size to a different value, ensure that the sum of the stack, heap, and sync buffer sizes does not exceed 32768 bytes.

Used for allocating any remaining file-scoped data that is not explicitly connected in the user graph.

heapsize=512

log-level

Log level for verbose logging. Only applicable when used with verbose. The specified range can be from 0 to 5, with increasing details provided in the log file as the number increases.

• 0 is the same as the quiet option
• 1 is the default logging of the compiler
• 2 is the default logging specified with verbose
• 3 - 5 are increased logging details when used with verbose

log-level=4

pl-freq

Specifies the interface frequency (in MHz) for all PL kernels and PLIOs. The default frequency is a quarter of the AI Engine frequency dependent on the specific device speed grade, and the maximum frequency is half of the AI Engine frequency. The PL frequency specific to each interface is provided in the graph.

 pl-freq=500

pl-register-threshold

Specifies the frequency (in MHz) threshold for registered AI Engine-PL crossings. The default frequency is one-eighth of the AI Engine frequency dependent on the specific device speed grade.

 pl-register-threshold=300

Important: Values above a quarter of the AI Engine array frequency are ignored, and a quarter is used instead.

stacksize

Stack size (in bytes) used by each AI Engine tile. The default stack size is set to 1024 bytes. Used as a standard compiler calling convention including stack-allocated local variables and register spilling.

Tip: The stack, heap, and sync buffer (32 bytes) are allocated up to 32768 bytes of data memory.Before changing the stack size to a different value, ensure that the sum of the stack, heap, and sync buffer sizes does not exceed 32768 bytes.

stacksize=512