FPGA AI Suite: IP Reference Manual

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ID 768974
Date 3/29/2024
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Document Table of Contents
Document Table of Contents x
1. FPGA AI Suite IP Reference Manual 2. About the FPGA AI Suite IP 3. FPGA AI Suite IP Generation Utility 4. FPGA AI Suite Ahead-of-Time Splitter Utility 5. CSR Map and Descriptor Queue A. FPGA AI Suite IP Reference Manual Archives B. FPGA AI Suite IP Reference Manual Document Revision History
2. About the FPGA AI Suite IP x
2.1. Supported Models 2.2. Model Performance 2.3. FPGA AI Suite Layer / Primitive Ranges 2.4. FPGA AI Suite IP Block Configuration 2.5. IP Block Interfaces
2.1. Supported Models x
2.1.1. MobileNet V2 differences between Caffe and TensorFlow models
2.2. Model Performance x
2.2.1. Throughput on the MobileNetV1 model (and other very fast models)
2.4. FPGA AI Suite IP Block Configuration x
2.4.1. Architecture Description File Format for Instance Parameterization 2.4.2. Architecture Description File Parameters
2.4.2. Architecture Description File Parameters x
2.4.2.1. Parameter Group: Global Parameters 2.4.2.2. Parameter Group: activation 2.4.2.3. Parameter Group: pe_array 2.4.2.4. Parameter Group: pool 2.4.2.5. Parameter Group: depthwise 2.4.2.6. Module: softmax 2.4.2.7. Parameter Group: dma 2.4.2.8. Parameter Group: xbar 2.4.2.9. Parameter Group: filter_scratchpad 2.4.2.10. Parameter Group: config_network 2.4.2.11. (Early Access) Parameter Group: layout_transform_params
2.5. IP Block Interfaces x
2.5.1. Clock and Reset 2.5.2. AXI Interfaces 2.5.3. AXI Interface Clock and Reset 2.5.4. Input Feature Tensor In-Memory Format 2.5.5. Output Tensor In-Memory Format
2.5.4. Input Feature Tensor In-Memory Format x
2.5.4.1. Multiple Input Graphs 2.5.4.2. Input Folding 2.5.4.3. Input Scale and Shift 2.5.4.4. Input Transform Mapping 2.5.4.5. Input Layout Transform Hardware
3. FPGA AI Suite IP Generation Utility x
3.1. IP Generation Utility Execution Flows 3.2. IP Generation Utility Inputs 3.3. IP Generation Utility Outputs 3.4. IP Generation Utility Command Line Options
3.4. IP Generation Utility Command Line Options x
3.4.1. The --flow create_ip Flow 3.4.2. The --flow add_arch Flow 3.4.3. The --flow list Flow 3.4.4. The --flow remove_arch Flow
4. FPGA AI Suite Ahead-of-Time Splitter Utility x
4.1. Files Generated by the FPGA AI Suite Ahead-of-Time (AOT) Splitter Utility 4.2. Building the FPGA AI Suite Ahead-of-Time (AOT) Splitter Utility 4.3. Running the FPGA AI Suite Ahead-of-Time (AOT) Splitter Utility 4.4. FPGA AI Suite Ahead-of-Time (AOT) Splitter Utility Example Application
5. CSR Map and Descriptor Queue x
5.1. Discovery ROM 5.2. Interrupt Control 5.3. DMA Descriptor Queue 5.4. DMA Control Registers 5.5. Performance Registers 5.6. Debug Network Registers 5.7. DMA License Register
1. FPGA AI Suite IP Reference Manual
2. About the FPGA AI Suite IP
3. FPGA AI Suite IP Generation Utility
4. FPGA AI Suite Ahead-of-Time Splitter Utility
5. CSR Map and Descriptor Queue
A. FPGA AI Suite IP Reference Manual Archives
B. FPGA AI Suite IP Reference Manual Document Revision History

2.5.5. Output Tensor In-Memory Format

The output tensor in-memory format is similar to the input tensor in-memory format described in Input Feature Tensor In-Memory Format. However, the output tensor is padded to the nearest multiple of KVEC rather than CVEC, with the padding being done at the boundaries between FPGA AI Suite IP outputs rather than strictly at the edge of the logical tensor output.

While the logical tensor output might be a single tensor, the FPGA AI Suite IP might compute this output as one single output or by slicing the output into smaller pieces.

Each scenario can result in a different output layout, with the first resulting in padding only on the boundary of the tensor as shown in the following figure:
Figure 5. Output Tensor In-Memory Layout Without Slicing
The second scenario results in padding within the logical tensor as well as on the boundary of the logical tensor as shown in the following figure:
Figure 6. Output In-Memory Layout With Slicing

To enable the plugin to determine the appropriate output layout and offsets, the compiler provides a DlaRuntimeOutputConfiguration object. One of the fields of this object is the output_tensor_mapping field, which provides a mapping from FPGA AI Suite IP tensor output to logical tensor output.

To show how the IP output tensor data is mapped to the logical output tensor for a compiled graph, the FPGA AI Suite compiler creates the following CSV files:
  • output_transform_dump_<graph-name>.csv

    This file describes the tensor shape and offsets.

  • output_transform_mapping_<graph-name>.csv

    This file shows the element-wise mapping of the FPGA AI Suite output tensor to the logical output tensor. This mapping is in the inverse of the input mapping described in Input Transform Mapping. Refer to the example in that topic for a description of the transform mapping CSV file.

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