移位寄存器_ttl164.vhd

含有各类寄存器

--TTL164 Shift Register
ENTITY dev164 IS
PORT(a, b, nclr, clock : IN BIT;
q : BUFFER BIT_VECTOR(0 TO 7));
END dev164;
ARCHITECTURE version1 OF dev164 IS
BEGIN
PROCESS(a,b,nclr,clock)
BEGIN
IF nclr = '0' THEN
q <= "00000000";
ELSE
IF clock'EVENT AND clock = '1'
THEN
FOR i IN q'RANGE LOOP
IF i = 0 THEN q(i) <= (a AND b);
ELSE
q(i) <= q(i-1);
END IF;
END LOOP;
END IF;
END IF;
END PROCESS;
END version1;