PACKAGE types IS
SUBTYPE nat8 is integer RANGE 255 DOWNTO 0;
END types;
USE work.types.all;
ENTITY gcd IS
PORT(reset : IN bit; -- Global reset
clk : IN bit; -- Global clock
rst : IN boolean;
xin : IN nat8;
yin : IN nat8;
rdy : OUT boolean;
oup : OUT nat8);
END gcd;
ARCHITECTURE algorithm OF gcd IS
BEGIN
gcd: PROCESS
VARIABLE x : nat8;
VARIABLE y : nat8;
VARIABLE h : nat8;
BEGIN
rdy <= true;
oup <= 0;
RESET_LOOP : LOOP
WAIT UNTIL clk = '1'; EXIT RESET_LOOP WHEN reset = '1';
WHILE (rst = true) LOOP
x := xin;
y := yin;
WAIT UNTIL clk = '1'; EXIT RESET_LOOP WHEN reset = '1';
END LOOP;
rdy <= false;
oup <= 0;
IF (x /= 0) AND (y /= 0) THEN
WHILE (y /= 0) LOOP
WHILE (x >= y) LOOP
WAIT UNTIL clk = '1'; EXIT RESET_LOOP WHEN reset = '1';
x := x - y;
END LOOP;
h := x; x := y; y := h;
END LOOP;
END IF;
rdy <= true;
oup <= x;
END LOOP RESET_LOOP;
END PROCESS gcd;
END algorithm;
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Process Statement must contain only one Wait Statement
