------------------------------------------------------------------------------- -- Synthesizable examples cover a large set of VHDL synthesizable constructs -- -- All examples have been synthesized with the Exemplar logic Core -- -- Copyright 1995, Zainalabedin Navabi navabi@ece.ut.ac.ir navabi@ece.neu.edu-- ------------------------------------------------------------------------------- LIBRARY ieee; USE ieee.std_logic_1164.ALL; -- LIBRARY exemplar; USE exemplar.exemplar_1164.ALL; USE exemplar.exemplar.ALL; ENTITY universal_synchronous_counter IS PORT (clock, reset, enable, updown : IN std_logic; count_out : INOUT std_logic_vector (7 DOWNTO 0)); END universal_synchronous_counter; ARCHITECTURE behavioral OF universal_synchronous_counter IS BEGIN counting : PROCESS (clock) BEGIN IF (clock = '1' AND clock'EVENT) THEN IF reset = '1' THEN count_out <= "00000000"; ELSE IF enable = '1' AND updown = '1' THEN count_out <= count_out + "01"; ELSIF enable = '1' AND updown = '0' THEN count_out <= count_out - "01"; END IF; END IF; END IF; END PROCESS; END behavioral; <div align="center"><br /><script type="text/javascript"><!-- google_ad_client = "pub-7293844627074885"; //468x60, Created at 07. 11. 25 google_ad_slot = "8619794253"; google_ad_width = 468; google_ad_height = 60; //--></script> <script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script><br /> </div>