Intel Agilex User Guide

2.1.3. Pre-adder for Fixed-Point Arithmetic
Each variable precision DSP block has two 19-bit pre-adders. You can configure these
pre-adders in the following configurations:
• 18-bit (signed or unsigned) addition or 18-bit (signed) subtraction for 18 x 19
mode
• 26-bit addition or subtraction for 27 x 27 mode
For 18 x 19 mode, when both pre-adders within the same DSP block are used, they
must share the same operation type (either addition or subtraction).
2.1.4. Internal Coefficient for Fixed-Point Arithmetic
The Intel Agilex variable precision DSP block has the flexibility of selecting the
multiplicand from either the dynamic input or the internal coefficient.
The internal coefficient can support up to eight constant coefficients for the
multiplicands in 18-bit and 27-bit modes. When you enable the internal coefficient
feature, COEFSELA/COEFSELB are used to control the selection of the coefficient
multiplexer.
2.1.5. Multipliers for Fixed-Point Arithmetic
A single-variable precision DSP block can perform many multiplications in parallel,
depending on the data width of the multiplier and implementation.
There are two multipliers per variable precision DSP block. You can configure these
two multipliers in several operational modes:
• Four 9 (signed) x 9 (signed) multipliers or four 8 (unsigned) x 8 (unsigned)
multipliers
• Two 18 (signed or unsigned) x 19 (signed) multipliers
• One 27 (signed) x 27 (signed) multiplier
2.1.6. Adder or Subtractor for Fixed-Point Arithmetic
Depending on the operational mode, you can use the adder or subtractor as one
38-bit adder for fixed-point arithmetic addition or subtraction between two multipliers
within a DSP block.
Use the dynamic SUB port to select the adder to perform addition or subtraction
operation.
Table 6.
Adder Operations with SUB Dynamic Control Signal
Operation Description
SUB Signal
Addition Adds the results of the two multipliers within one DSP block. 0
Subtraction Subtracts the results between two multipliers within the same DSP
block.
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2. Intel Agilex Variable Precision DSP Blocks Architecture
UG-20213 | 2019.04.02
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Variable Precision DSP Blocks User Guide
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Intel Agilex Specifications

General

Brand	Intel
Model	Agilex
Category	Microcontrollers
Language	English