Following are the different types of DSP primitives for Versal ACAP.
|DSP58||Standard integer/Fixed point mode||Inference or instantiation|
|DSPFP32||Floating point mode||Instantiation only|
|DSPCPLX||Complex multiplier||Inference or instantiation|
For Versal ACAPs, the DSP58 primitive includes the same features as in UltraScale devices, including a multiplier, adder, pre-adder, and registers to fully pipeline the primitive. However, sizing differs and the primitives include additional features.
For signed logic, you can configure DSP58 as follows:
- Multiplier: 27x24
- Adder: 58-bit
- Pre-adder: 27-bit
For unsigned logic, you can configure DSP58 as follows:
- Multiplier: 26x23
- Adder: 57-bit
- Pre-adder: 26-bit
The following figures show examples for signed logic.
The DSP58 can implement a dot product, which is a multiplier that is represented as three smaller multipliers that are added together. Dot products are often used in filters in image processing. For more information, see the Versal ACAP DSP Engine Architecture Manual (AM004). The following figure shows an example of a dot product with an extra adder.
The following figures show the RTL for a dot product.
DSPFP32 can perform floating point calculations. Vivado synthesis does not handle these calculations. Instead, various IP are provided, or the DSPFP32 primitive can be instantiated.
The DSPCPLX is designed to synthesize logic needed to solve for the real and imaginary portions of the following equation:
Each DSPCPLX occupies two DSP58 sites. The DSPCPLX can either be instantiated in the RTL or inferred. The following figures show the RTL for the DSPCPLX.