Integer Arithmetic Intel® FPGA IP Cores User Guide

ID 683490
Date 4/01/2024
Document Table of Contents

5.6. Parameters

The following table lists the LPM_ADD_SUB IP core parameters.

Table 17.  LPM_ADD_SUB IP Core Parameters
Parameter Name Type Required Description
LPM_WIDTH Integer Yes Specifies the widths of the dataa[], datab[], and result[] ports.
LPM_DIRECTION String No Values are ADD, SUB, and UNUSED. If omitted, the default value is DEFAULT, which directs the parameter to take its value from the add_sub port. The add_sub port cannot be used if LPM_DIRECTION is used. Intel® recommends that you use the LPM_DIRECTION parameter to specify the operation of the LPM_ADD_SUB function, rather than assigning a constant to the add_sub port.
LPM_REPRESENTATION String No Specifies the type of addition performed. Values are SIGNED and UNSIGNED. If omitted, the default value is SIGNED. When this parameter is set to SIGNED, the adder/subtractor interprets the data input as signed two's complement.
LPM_PIPELINE Integer No Specifies the number of latency clock cycles associated with the result[] output. A value of zero (0) indicates that no latency exists, and that a purely combinational function will be instantiated. If omitted, the default value is 0 (non-pipelined).
LPM_HINT String No Allows you to specify Intel® -specific parameters in VHDL design files (.vhd). The default value is UNUSED.
LPM_TYPE String No Identifies the library of parameterized modules (LPM) entity name in VHDL design files.
ONE_INPUT_IS_CONSTANT String No Intel® -specific parameter. You must use the LPM_HINT parameter to specify the ONE_INPUT_IS_CONSTANT parameter in VHDL design files. Values are YES, NO, and UNUSED. Provides greater optimization if one input is constant. If omitted, the default value is NO.
MAXIMIZE_SPEED Integer No Intel® -specific parameter. You must use the LPM_HINT parameter to specify the MAXIMIZE_SPEED parameter in VHDL design files. You can specify a value between 0 and 10. If used, the Quartus® Prime software attempts to optimize a specific instance of the LPM_ADD_SUB function for speed rather than routability, and overrides the setting of the Optimization Technique logic option. If MAXIMIZE_SPEED is unused, the value of the Optimization Technique option is used instead. If the setting for MAXIMIZE_SPEED is 6 or higher, the Compiler optimizes the LPM_ADD_SUB IP core for higher speed using carry chains; if the setting is 5 or less, the Compiler implements the design without carry chains. This parameter must be specified for Cyclone, Stratix, and Stratix GX devices only when the add_sub port is not used.
INTENDED_DEVICE_FAMILY String No This parameter is used for modeling and behavioral simulation purposes. The parameter editor calculates the value for this parameter.