RASSP-Sanders Project - Reduced Activity



 
--	Model Name	: Reduced Activity - Parwan Memory 

--	Author		: Zainalabedin Navabi 

--	Last Updated	: 09 / 15 / 1996

--	This document is © copyrighted by the Author.

LIBRARY IEEE;
USE IEEE.std_logic_1164.ALL;
--
LIBRARY EXEMPLAR;
USE EXEMPLAR.exemplar_1164.ALL;
USE EXEMPLAR.exemplar.ALL;
--
LIBRARY WORK;
USE WORK.synthesis_parameters.ALL;
USE WORK.synthesis_utilities.ALL;
USE WORK.global_environment.ALL;
--
ENTITY parwan_memory IS
PORT (cs, rwbar : IN std_logic);
END parwan_memory;
--
ARCHITECTURE behavioral OF parwan_memory IS
TYPE byte_memory IS ARRAY ( INTEGER RANGE <> ) OF std_logic_vector ( 7 DOWNTO 0 );
-- SIGNAL da : std_logic_vector ( 7 DOWNTO 0 );
-- SIGNAL ad : std_logic_vector ( 11 DOWNTO 0 );
BEGIN
mem : PROCESS
VARIABLE memory : byte_memory ( 0 TO 63 ) :=
("00000000", "00011000", "10100000", "00011001", --00: lda 24, sta 25
"00100000", "00011010", "01000000", "00011011", --04: and 26, add 27
"11100010", "11101001", "01100000", "00011100", --08: cac, asr, sub 28
"00010000", "00011101", "11000000", "00100100", --12: lda i 29, jsr 36
"11101000", "11100000", "10000000", "00100000", --16: asl, nop, jmp 32
"00000000", "00000000", "00000000", "00000000", --20:
"01011100", "00000000", "01110000", "00010010", --24: (24, 25, 26, 27)
"00001100", "00011111", "00000000", "01011010", --28: (28, 29, 30, 31)
"10000000", "00010010", "00000000", "00000000", --32: jmp 18
"00000000", "11100010", "10010000", "00100100", --36: , cma, jmp i 36
"00000000", "00000000", "00000000", "00000000",
"00000000", "00000000", "00000000", "00000000",
"00000000", "00000000", "00000000", "00000000",
"00000000", "00000000", "00000000", "00000000",
"00000000", "00000000", "00000000", "00000000",
"00000000", "00000000", "00000000", "00000000" );
VARIABLE ia : INTEGER;
BEGIN
IF cs = '1' THEN
WAIT FOR 1 FS;
ia := evec2int (adbus);
IF rwbar = '1' THEN
IF ia >= 64 THEN
databus := "ZZZZZZZZ";
ELSE
databus := memory (ia);
END IF;
ELSIF rwbar = '0' THEN
IF ia < 64 THEN
memory (ia) := databus;
END IF;
END IF;
-- da <= databus; ad <= adbus;
WAIT ON cck;
databus := "ZZZZZZZZ";
END IF;
WAIT ON cs;
END PROCESS mem; END behavioral;