Use of parameterized module library (LPM)

LPM (Library Parameterized Modules) is a Parameterized macro function module Library. Using these functional module libraries can greatly improve the efficiency of icdesign. The LPM standard was introduced in 1990. In April 1993, LPM, as a subsidiary standard of the Electronic Design interchange format (EDIF), was incorporated into the temporary standard of the Electronic Industry Association (EIA.

It is very convenient to call the LPM library function in MAX + plus ii and Quartus II. You can either directly call the function in the Graphic Input Method or in the HDL source file.

The LPM library is shown in Table 2-5. It is a function module provided by MAX + plus ii and Quartus II for calling.

The directory where the LPM library of MAX + plus ii is located is/maxplus2/max2lib/mega_lpm. The directory where the LPM library of Quartus II is located is/altera/quartus60/libraries/megas.

Table 2-5 LPM Library Unit list

Module category	Macro Unit	Brief Description
Door unit module	Lpm_and	Parameterization and gate
	Lpm_bustri	Parameterized three-state Buffer
	Lpm_clshift	Parameterized combination logic Positioner
	Lpm_constant	Parameterized constant Generator
	Lpm_decode	Parameterized Decoder
	Lpm_inv	Parameterized Reverser
	Lpm_mux	Parameterized multi-path Selector
	Busmux	Parameterized bus Selector
	MUX	Multi-path Selector
	Lpm_or	Parameterization or gate
	Lpm_xor	Parameterized exclusive OR gate
Arithmetic Operation Module	Lpm_abs	Parameterized absolute value calculation
	Lpm_add_sub	Parameterized addition/Subtraction
	Lpm_compare	Parameterized Comparator
	Lpm_counter	Parameterized counter
	Lpm_mult	Parameterized Multiplier
Memory Module	Lpm_ff	Parameterized D Trigger
	Lpm_latch	Parameterized latches
	Lpm_ram_dq	Input/Output separate parameterized Ram
	Lpm_ram_io	Parameterized RAM for input and output multiplexing
	Lpm_rom	Parameterized Rom
	Lpm_shitreg	Parameterized shift register
	Csfifo	Parameterization first-in-first-out queue
	Csdpram	Parameterized dual-port RAM
Other functional modules	Pll	Parameterized Phase-Locked Loop Circuit
	Ntsc <	NTSC image control signal generator

      Appendix: Use the LPM Library Unit to construct a four-digit Calculator

The following describes how to use the LPM Library Unit to construct a four-bit calculator.

Lpm_add_sub is a parameterized addition/subtraction operator. It can be used to design the addition or subtraction operator. Compile

Edit the logstore, as shown in Figure 2-7.

Figure 2-7 parameterized addition/subtraction lpm_add_sub

Specify the following parameter values,

LPM_WIDTH = 4 (module signal width is 4 bits)

LPM_DIRECTION = "ADD" (set the module as a calculator)

LPM_REPRESENTATION = "UNSIGNED" (set the input and output data to the UNSIGNED number)

Then you need to set the port. Here, only four ports of the lpm_add_sub Library Unit are used, which are the data input ports.

Data-a [] and data-B [], result [] At the data output end, And cout at the input output end. The simulation results are shown in Figure 2-8.

Figure 2-8lpm_add_sub simulation image when it is set as a multiplier