AR# 10234

3.1i Foundation ISE - Latches are missing from the Spartan-XL library components.

Description

Keywords: ISE, Schematic, Editor, Spartan-XL, latches, LD, library, components

Urgency: Standard

General Description:
3.1i ISE Schematic Editor library for Spartan-XL does not contain latch primitives.

Solution

1

This will be fixed in a future software release.

2

In the meantime, here is a work-around for the problem:

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity latch is
Port ( AIN : in std_logic;
BIN : in std_logic;
A_OUT : out std_logic);
end latch;

architecture behavioral of latch is

component ILDX_1
port(
Q : out STD_ULOGIC;
D : in STD_ULOGIC;
G : in STD_ULOGIC;
GE : in STD_ULOGIC);
end component;

component VCC
port(
P : out STD_ULOGIC );
end component;

component INV
port(
O : out STD_ULOGIC;
I : in STD_ULOGIC);
end component;

Signal A1 : std_logic;
Signal A2 : std_logic;

begin

U0 : ILDX_1
port map ( Q => A_OUT, D => AIN, G => A2, GE => A1);
U1 : Vcc
port map ( P => A1);
U2 : INV
port map ( I => BIN, O => A2);

end behavioral;

This creates an ILDI latch.
AR# 10234
Date 01/15/2003
Status Archive
Type General Article