--************************************************************************ --** MODEL : package_timing.vhd ** --** COMPANY : Cypress Semiconductor ** --** REVISION: 1.0 (Created new timing package model) ** --************************************************************************ library IEEE,std; use IEEE.std_logic_1164.all; use IEEE.std_logic_arith.all; use IEEE.std_logic_unsigned.all; use ieee.std_logic_textio.all ; use std.textio.all ; --**************************************************************** package package_timing is ------------------------------------------------------------------------------------------------ -- Read Cycle timing ------------------------------------------------------------------------------------------------ constant tRC : TIME := 10 ns; -- Read Cycle Time constant tAA : TIME := 10 ns; -- Address to Data Valid constant tOHA : TIME := 3 ns; -- Data Hold from Address Change constant tACE : TIME := 10 ns; -- Random access CEb Low to Data Valid constant tDOE : TIME := 5 ns; -- OE Low to Data Valid constant tLZOE : TIME := 1 ns; -- OE Low to LOW Z constant tHZOE : TIME := 5 ns; -- OE High to HIGH Z constant tLZCE : TIME := 3 ns; -- CEb LOW to LOW Z constant tHZCE : TIME := 5 ns; -- CEb HIGH to HIGH Z constant tDBE : TIME := 5 ns; -- BHE/BLE LOW to Data Valid constant tLZBE : TIME := 1 ns; -- BHE/BLE LOW to LOW Z constant tHZBE : TIME := 5 ns; -- BHE/BLE HIGH to HIGH Z ------------------------------------------------------------------------------------------------ -- Write Cycle timing ------------------------------------------------------------------------------------------------ constant tWC : TIME := 10 ns; -- Write Cycle Time constant tSCE : TIME := 7 ns; -- CEb LOW to Write End constant tAW : TIME := 7 ns; -- Address Setup to Write End constant tSA : TIME := 0 ns; -- Address Setup to Write Start constant tHA : TIME := 0 ns; -- Address Hold from Write End constant tPWE : TIME := 7 ns; -- WEb pulse width constant tSD : TIME := 5.5 ns; -- Data Setup to Write End constant tHD : TIME := 0 ns; -- Data Hold from Write End constant tBW : TIME := 7 ns; -- BHE BLE Setup to Write End constant tLZWE : TIME := 3 ns; -- WEb Low to High Z constant tHZWE : TIME := 5 ns; -- WEb High to Low Z end package_timing; package body package_timing is end package_timing;