Stratix V DSP Block

With the variable-precision digital signal processing (DSP) block, the Stratix® V FPGA supports, on a block-by-block basis, various precisions ranging from 9-bit x 9-bit up to single-precision floating point (mantissa multiplication) within a single DSP block. This frees you from FPGA architecture restrictions, allowing you to use the optimum precision at each stage of the DSP datapath. You'll also benefit from increased system performance, reduced power consumption, and reduced architectural constraints. Figure 1 shows the Stratix V FPGA variable-precision DSP block architecture in the 18-bit precision mode. Figure 2 shows the Stratix V FPGA variable-precision DSP block architecture in the high-precision mode.

Figure 1. Stratix V FPGA Variable-Precision DSP Block Architecture, 18-Bit Precision Mode

Figure 2. Stratix V FPGA Variable-Precision DSP Block Architecture, High-Precision Mode

Stratix V FPGA DSP Precision Range

Table 1: Stratix V FPGA DSP Blocks in Single-Block Mode

Single Variable-Precision DSP Block Stratix V FPGA DSP Blocks
Three independent multipliers 9x9
Two multipliers in sum mode 18x18
Two multipliers in sum mode 16x16
Independent asymmetric 18x36
Independent high precision 27x27

Table 2: Stratix V FPGA DSP Blocks in Multiple-Block Mode

Multiple Variable-Precision DSP Blocks in Cascade Mode Stratix V FPGA DSP Blocks
One independent 36x36 2
One independent 54x54 4 (1)
18x18 complex multiply 2
18x25 complex multiply 3
18x36 complex multiply 4
27x27 complex multiply 4

Note:

  1. Requires additional logic outside the DSP block

Cascade Bus

All modes feature a 64-bit accumulator and each variable-precision DSP block comes with a 64-bit cascade bus that allows the implementation of even higher precision signal processing by cascading multiple blocks using a dedicated bus.

The variable-precision DSP architecture maintains backward compatibility. It can efficiently support existing 18-bit DSP applications, such as high-definition video processing, digital up or down conversion, and multi-rate filtering.

Applications for Stratix V FPGAs

  • Video processing applications
  • Wireless applications
  • Medical applications
  • Test and measurement applications
  • Military radar applications