brainfuck_processor/fpga/src/cellMemory.vhd

43 lines
1.1 KiB
VHDL

-- cellMemory.vhd
-- Created on: Di 26. Sep 11:39:10 CEST 2023
-- Author(s): Yannick Reiß
-- Content: Cell memory as part of brainfuck logic
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
-- Entity cellblock
entity cellblock is
port(
clk : in std_logic; -- clock with speed of board clock
enable : in std_logic;
address : in std_logic_vector(15 downto 0);
new_cell : in std_logic_vector(7 downto 0);
old_cell : out std_logic_vector(7 downto 0)
);
end cellblock;
-- Architecture arch of cellblock: read on every clock cycle to cell.
architecture arch of cellblock is
type empty is array(0 to 65535) of std_logic_vector(7 downto 0);
signal memory : empty := (others => (others => '0'));
begin
-- Process clk_read
clk_read : process (clk, enable) -- runs only, when clk changed
begin
if rising_edge(clk) and enable = '1' then
memory(to_integer(unsigned(address))) <= new_cell;
end if;
end process;
old_cell <= memory(to_integer(unsigned(address)));
end arch;