FPGA AI Suite Handbook

ID 863373
Date 11/21/2025
Public
Document Table of Contents

9.5. FPGA AI Suite IP Supported Layers and Hyperparameter Ranges

Each layer in the intermediate representation (IR) must be validated against the layer and primitive constraints. This step ensures that the design flow only progresses with operator dimensions and hyperparameters supported by the FPGA AI Suite hardware.

Validation at this stage prevents errors during architecture generation and guarantees that all layers can be synthesized into FPGA-ready IP without unsupported fallbacks.

The following table lists the hyperparameter ranges supported by key primitive layers in the FPGA AI Suite IP:

Table 32.  Supported Layers and Hyperparameter Ranges

Layer / Primitive

Hyperparameter

Supported Range

Fully connected

None

n/a

2D Convolution

Filter Size

Width = [1..28]

Height = [1..28]

Height does not have to equal width.

Default value for each is 14.

Stride

Maximum stride is 15

Pad

Maximum pad is (216) - 1

3D Convolution Filter Size Width = [1..28]

Height = [1..28]

Depth = [1..14]

Filter volume should fit into the filter cache size.

Stride Maximum stride is 15.
Pad Maximum pad is (216) - 1

Depthwise

Filter Size

Same as 2D Conv filter size

Depth = 1

Stride

Same as 2D Conv stride

Depth = 1

Pad

Same as 2D conv padding

Depth = 1

Scale-Shift

Scale factor

FP16 float range

Bias term

FP16 float range

Deconvolution / Transpose Convolution

Filter Size

Any – Same as convolution, and height/width can be different

Depth = 1

Stride

1, 2, 4, 8 (stride width == stride height)

Depth = 1

Pad

Restricted to filter_[height, width] - 1

Depth = 1

ReLU

n/a

n/a

pReLU

Scaling parameter (a) (1 per filter / conv output channel)

float range

Depth = 1

Leaky ReLU

Scaling parameter (a) (1 per tensor)

float range

Clamp

Limit parameters (a, b) (1 per tensor)

float range

Round_Clamp Limit parameters (a, b) (1 per tensor) float range

H-sigmoid

n/a

n/a

H-swish

n/a

n/a

Sigmoid n/a FP16 float range
Swish n/a FP16 float range
Tanh n/a FP16 float range

Max Pool

Window Size

up to 13x13x13

Pad

1, 2

Stride

1, 2, 3, 4

Average Pool

Window Size

Up to 27x27 (one less than the maximum 2D convolution size)

Width == Height

Depth = 1 or 2

Pad

1, 2

Stride

1, 2, 3, 4

Softmax

Maximum Number of Channels

4096

Elementwise Multiplication of feature * filter and feature * feature tensors.19

n/a

Tensor sizes are expanded if necessary to support the multiplication.

Depth = 1

ChannelToSpace

DepthToSpace

PixelShuffle

block_mode blocks_first or blocks_last
block_size 2, 4, 8
Upsampling

Downsampling

Interpolation Type Bilinear (upsampling only) or Nearest Neighbor (upsampling and downsampling
Filter Size Similar to 2D convolution except that width and height must be symmetrical for bilinear interpolation.

Downsampling supports a sampling factor (ratio between an output dimension and input dimension) of only 2x or 4x.

19 This is an element-wise multiplication, not a matrix multiply operation.