Variable Precision DSP Blocks User Guide: Agilex™ 5 FPGAs and SoCs

ID 813968
Date 9/20/2024
Public
Document Table of Contents

6.3.4. Preadder Tab

Table 95.  Preadder Tab
Parameter Value Default Value Description
Select preadder mode

SIMPLE,

COEF,

INPUT,

SQUARE,

CONSTANT

SIMPLE

Specifies the operation mode for preadder module.

SIMPLE: This mode bypass the preadder. This is the default mode.

COEF: This mode uses the output of the preadder and coefsel input bus as the inputs to the multiplier.

INPUT: This mode uses the output of the preadder and datac input bus as the inputs to the multiplier.

SQUARE: This mode uses the output of the preadder as both the inputs to the multiplier.

CONSTANT: This mode uses dataa input bus with preadder bypassed and coefsel input bus as the inputs to the multiplier.

Select preadder direction

ADD,

SUB

ADD Specifies the operation of the preadder.
To enable this parameter, select the following for Select preadder mode:
  • COEF
  • INPUT
  • SQUARE or
  • CONSTANT
How wide should the C input buses be? 1 - 256 16 Specifies the number of bits for C input bus.

You must select INPUT for Select preadder mode to enable this parameter.

Data C Input Register Configuration
Register datac input

On

Off

On Turn on this option to enable input register for datac input bus.

You must set INPUT to Select preadder mode parameter to enable this option.

What is the source for clock input?

Clock0

Clock1

Clock2

Clock0 Select Clock0 , Clock1 or Clock2 to specify the input clock signal for datac input register.

You must select Register datac input to enable this parameter.

What is the source for asynchronous clear input?

NONE

ACLR0

ACLR1

NONE Specifies the asynchronous clear source for the datac input register.

You must select Register datac input to enable this parameter.

The IP core supports either asynchronous or synchronous clear but not both.

What is the source for synchronous clear input?

NONE

SCLR0

SCLR1

NONE Specifies the synchronous clear source for the datac input register.

You must select Register datac input to enable this parameter.

The IP core supports either asynchronous or synchronous clear but not both.

Coefficients
How wide should the coef width be? 1 - 27 18 Specifies the number of bits for coefsel input bus.

You must select COEF or CONSTANT for preadder mode to enable this parameter.

Coef Register Configuration
Register the coefsel input

On

Off

Checked Select this option to enable input register for coefsel input bus.

You must select COEF or CONSTANT for preadder mode to enable this parameter.

What is the source for clock input?

Clock0

Clock1

Clock2

Clock0 Select Clock0 , Clock1 or Clock2 to specify the input clock signal for coefsel input register.

You must select Register the coefsel input to enable this parameter.

What is the source for asynchronous clear input?

NONE

ACLR0

ACLR1

NONE Specifies the asynchronous clear source for the coefsel input register.

You must select Register the coefsel input to enable this parameter.

The IP core supports either asynchronous or synchronous clear but not both.

What is the source for synchronous clear input

NONE

SCLR0

SCLR1

NONE Specifies the synchronous clear source for the coefsel input register.

You must select Register the coefsel input to enable this parameter.

The IP core supports either asynchronous or synchronous clear but not both.

Coefficient_0 Configuration 0x00000 – 0xFFFFFFF 0x00000000 Specifies the coefficient values for this first multiplier.

The number of bits must be the same as specified in How wide should the coef width be? parameter.

You must select COEF or CONSTANT for preadder mode to enable this parameter.

Coefficient_1 Configuration 0x00000 – 0xFFFFFFF 0x00000000 Specifies the coefficient values for this second multiplier.

The number of bits must be the same as specified in How wide should the coef width be? parameter.

You must select COEF or CONSTANT for preadder mode to enable this parameter.

Coefficient_2 Configuration 0x00000 – 0xFFFFFFF 0x00000000 Specifies the coefficient values for this third multiplier.

The number of bits must be the same as specified in How wide should the coef width be? parameter.

You must select COEF or CONSTANT for preadder mode to enable this parameter.

Coefficient_3 Configuration 0x00000 – 0xFFFFFFF 0x00000000 Specifies the coefficient values for this fourth multiplier.

The number of bits must be the same as specified in How wide should the coef width be? parameter.

You must select COEF or CONSTANT for preadder mode to enable this parameter.