This file contains a more verbose and detailed description of the Vela Compiler's CLI options than the built-in help strings. It also defines and describes the Vela system configuration file format.
Filename of the network model to compile. The file has to be a .tflite file.
Type: POSIX path
Default: N/A
vela path/to/network.tflite
Displays the help strings of all CLI options. Can be used without the required Network argument.
Type: N/A
Default: N/A
vela --help
Displays the version of the installed Vela Compiler. Can be used without the required Network argument.
Type: N/A
Default: N/A
vela --version
Specifies the output directory of the optimised network model as well as the .csv files containing performance estimations.
Type: POSIX path
Default: ./output
vela network.tflite --output-dir ./custom_directory
Specifies the path to the config file. The file has to be a .ini file. The format is described further in a the Config section below.
Type: POSIX path
Default: use default configuration
vela network.tflite --config custom_config.ini
Controls the packing of multiple passes into cascades. This allows for lower memory usage. If the network's intermediate feature maps are too large for the system's SRAM this optimisation is required.
Type: Boolean
Default: True
vela network.tflite --cascading False
Controls the overlapping of IFM and OFM buffers. This means that IFM and OFM buffers may overlap if possible. This allows for lower memory usage.
Type: Boolean
Default: True
vela network.tflite --ifm-ofm-overlap False
Force a specific block configuration in the format HxWxC, where H, W, and C are positive integers specifying height, width, and channels (depth), respectively. The default behaviour is Vela searching for an optimal block configuration. An exception will be raised if the chosen block configuration is incompatible.
Type: String
Default: N/A
vela network.tflite --force-block-config 2x2x8
Measure time taken for different compiler steps, e.g. model reading and scheduling. Prints the results to standard out.
Type: Set True
Default: False
vela network.tflite --timing
Choose which hardware accelerator configuration to compile for. Format is accelerator name followed by a hyphen, followed by the number of MACs in the configuration. Type: String
Default: ethos-u55-256
Choices: [ethos-u55-32, ethos-u55-64, ethos-u55-128, ethos-u55-256]
vela network.tflite --accelerator-config ethos-u55-64
Selects the system configuration to use as specified in the System Configuration File (see section below).
Type: String
Default: Use internal default config
vela network.tflite --system-config MySysConfig
Specify memory area to be used for permanent storage. This area is where weights, bias and other constant data will be stored. OnChipFlash means reading directly from this storage, i.e. not using the DMA. To solely run from SRAM, OnChipFlash should be selected.
Type: String
Default: OffChipFlash
vela network.tflite --permanent-storage OnChipFlash
Specify which allocator algorithm to use for non-constant NPU and CPU tensor allocation.
Type: String
Default: Greedy
Choices: [Greedy, LinearAlloc]
vela network.tflite --tensor-allocator=LinearAlloc
Controls scheduler IFM streaming search. Vela's scheduler will choose between IFM Streaming and Weight Streaming for optimal memory usage. Disabling this will cause Vela to always choose Weight Streaming.
Type: Boolean
Default: True
vela network.tflite --ifm-streaming False
Limit the block config search space. This will result in faster compilation times but may impact the performance of the output network. Use 0 for unlimited search.
Type: Integer
Choices: >= 0
Default: 16
vela network.tflite --block-config-limit 0
Performs an additional scaling of the individual memory clock scales specified by the system configuration. Used to globally adjust the bandwidth of the various memories
Type: Float
Default: 1.0
vela network.tflite --global-memory-clock-scale 1.5
Controls the calculation of the pareto metric. Use 'BwCycMemBlkH' to consider Block Height in addition to Bandwidth, Cycle count and Memory. This can reduce SRAM usage in some circumstances.
Type: String
Default: BwCycMem
Choices: [BwCycMem, BwCycMemBlkH]
vela network.tflite --pareto-metric BwCycMemBlkH
Some of Vela's algorithms use recursion and the required depth can be network dependant. This option allows the limit to be increased if needed. The maximum limit is platform dependent. If limit is set too low then compilation will raise a RecursionError exception.
Type: Integer
Default: 10000
vela network.tflite --recursion-limit 50000
Set the maximum value that can be used for the block dependency delay between NPU kernel operations. A lower value may result in longer execution time.
Type: Integer
Default: 3
Choices: [0, 1, 2, 3]
vela network.tflite --max-block-dependency 0
Controls if NHCWB16 or NHWC Tensor format should be used in between cascaded passes. NHWCB16 means FeatureMaps are laid out in 1x1x16B bricks in row-major order. This enables more efficient FeatureMap reading from external memory.
Type: Boolean
Default: True
Choices: [True, False]
vela network.tflite --nhcwb16-between-cascaded-passes
All of the options below are disabled by default and enabling them will add prints to standard out without any functional changes.
Prints a summary of all the subgraphs and their inputs and outputs.
vela network.tflite --show-subgraph-io-summary
Prints the minimum possible allocation.
vela network.tflite --show-minimum-possible-allocation
Show the operations that fall back to the CPU.
vela network.tflite --show-cpu-operations
Verbose graph rewriter.
vela network.tflite --verbose-graph
Verbose quantization.
vela network.tflite --verbose-quantization
Verbose pass packing.
vela network.tflite --verbose-packing
Verbose tensor purpose.
vela network.tflite --verbose-tensor-purpose
Verbose tensor format.
vela network.tflite --verbose-tensor-format
Verbose schedule.
vela network.tflite --verbose-schedule
Show all schedules along the pareto frontier of optimisation criteria.
vela network.tflite --verbose-pareto-frontier-schedules
Verbose tensor allocation.
vela network.tflite --verbose-allocation
Verbose high level command stream.
vela network.tflite --verbose-high-level-command-stream
Verbose register command stream.
vela network.tflite --verbose-register-command-stream
Verbose operator list.
vela network.tflite --verbose-operators
This is used to describe various properties of the embedded system that the network will run in. The configuration file is selected with the --config CLI option. The system config is selected by Name (defined in the [SysConfig.Name] field) with the CLI option --system-config. The cpu=X attribute in the [SysConfig.Name] is used to cross-reference and select CPU operator attributes in the [CpuPerformance.OpName] section.
Example usage based on the file below:
vela network.tflite --config sys_cfg_vela.ini --system-config MySysConfig
Example of a Vela system configuration file.
; File: sys_cfg_vela.ini ; The file contains two parts; a system config part and a CPU operator ; performance part. ; System config ; Specifies properties such as the core clock speed, the size and speed of the ; four potential memory areas, and for various types of data which memory area ; is used to store them. The cpu property is used to link with the CPU operator ; performance. ; The four potential memory areas are: Sram, Dram, OnChipFlash, OffChipFlash. [SysConfig.MySysConfig] npu_freq=500e6 cpu=MyCpu Sram_clock_scale=1 Sram_port_width=64 Dram_clock_scale=1 Dram_port_width=64 OnChipFlash_clock_scale=1 OnChipFlash_port_width=64 OffChipFlash_clock_scale=0.25 OffChipFlash_port_width=32 permanent_storage_mem_area=OffChipFlash feature_map_storage_mem_area=Sram fast_storage_mem_area=Sram ; CPU operator performance ; Specifies properties that are used by a linear model to estimate the ; performance for any operations that will be run on the CPU (such as those not ; supported by the NPU). Setting the intercept and slope to 0 will result in ; the operator being excluded from the performance estimation. This is the same ; as not specifying the operator. If an explicit cpu is specified rather than ; using the default then the cpu name must match the cpu specified in the ; SysConfig.<system config name> section. [CpuPerformance.MyCpuOperator] default.intercept=0.0 default.slope=1.0 MyCpu.intercept=0.0 MyCpu.slope=1.0