--
entity motones_sim is
- port ( rst_n : in std_logic
+ port (
+ base_clk : in std_logic;
+ rst_n : in std_logic;
+ joypad1 : in std_logic_vector(7 downto 0);
+ joypad2 : in std_logic_vector(7 downto 0);
+ vga_clk : out std_logic;
+ h_sync_n : out std_logic;
+ v_sync_n : out std_logic;
+ r : out std_logic_vector(3 downto 0);
+ g : out std_logic_vector(3 downto 0);
+ b : out std_logic_vector(3 downto 0)
);
end motones_sim;
port ( base_clk : in std_logic;
reset_n : in std_logic;
cpu_clk : out std_logic;
- ppu_clk : out std_logic
+ ppu_clk : out std_logic;
+ mem_clk : out std_logic;
+ vga_clk : out std_logic
);
end component;
component address_decoder
generic (abus_size : integer := 16; dbus_size : integer := 8);
port ( phi2 : in std_logic;
+ mem_clk : in std_logic;
R_nW : in std_logic;
- addr : in std_logic_vector (abus_size - 1 downto 0);
- d_io : inout std_logic_vector (dbus_size - 1 downto 0);
+ addr : in std_logic_vector (abus_size - 1 downto 0);
+ d_io : in std_logic_vector (dbus_size - 1 downto 0);
+ rom_ce_n : out std_logic;
+ ram_ce_n : out std_logic;
ppu_ce_n : out std_logic;
apu_ce_n : out std_logic
);
end component;
+ component ram
+ generic (abus_size : integer := 16; dbus_size : integer := 8);
+ port (
+ clk : in std_logic;
+ ce_n, oe_n, we_n : in std_logic; --select pin active low.
+ addr : in std_logic_vector (abus_size - 1 downto 0);
+ d_io : inout std_logic_vector (dbus_size - 1 downto 0)
+ );
+ end component;
+
+ component prg_rom
+ generic (abus_size : integer := 15; dbus_size : integer := 8);
+ port (
+ clk : in std_logic;
+ ce_n : in std_logic; --active low.
+ addr : in std_logic_vector (abus_size - 1 downto 0);
+ data : out std_logic_vector (dbus_size - 1 downto 0)
+ );
+ end component;
+
component ppu
port ( clk : in std_logic;
+ mem_clk : in std_logic;
ce_n : in std_logic;
rst_n : in std_logic;
r_nw : in std_logic;
component v_address_decoder
generic (abus_size : integer := 14; dbus_size : integer := 8);
port ( clk : in std_logic;
+ mem_clk : in std_logic;
rd_n : in std_logic;
wr_n : in std_logic;
ale : in std_logic;
- vram_ad : inout std_logic_vector (7 downto 0);
- vram_a : in std_logic_vector (13 downto 8)
+ v_addr : in std_logic_vector (13 downto 0);
+ v_data : in std_logic_vector (7 downto 0);
+ nt_v_mirror : in std_logic;
+ pt_ce_n : out std_logic;
+ nt0_ce_n : out std_logic;
+ nt1_ce_n : out std_logic
);
end component;
- component vga_device
- port ( vga_clk : in std_logic;
- rst_n : in std_logic;
- h_sync_n : in std_logic;
- v_sync_n : in std_logic;
- r : in std_logic_vector(3 downto 0);
- g : in std_logic_vector(3 downto 0);
- b : in std_logic_vector(3 downto 0)
- );
+ component chr_rom
+ generic (abus_size : integer := 13; dbus_size : integer := 8);
+ port (
+ clk : in std_logic;
+ ce_n : in std_logic; --active low.
+ addr : in std_logic_vector (abus_size - 1 downto 0);
+ data : out std_logic_vector (dbus_size - 1 downto 0);
+ nt_v_mirror : out std_logic
+ );
+ end component;
+
+ component ls373
+ generic (
+ dsize : integer := 8
+ );
+ port ( c : in std_logic;
+ oc_n : in std_logic;
+ d : in std_logic_vector(dsize - 1 downto 0);
+ q : out std_logic_vector(dsize - 1 downto 0)
+ );
end component;
component apu
);
end component;
- ---clock frequency = 21,477,270 (21 MHz)
- constant base_clock_time : time := 46 ns;
- constant vga_clk_time : time := 40 ns;
constant data_size : integer := 8;
constant addr_size : integer := 16;
- constant size14 : integer := 14;
+ constant vram_size14 : integer := 14;
+
+ constant ram_2k : integer := 11; --2k = 11 bit width.
+ constant rom_32k : integer := 15; --32k = 15 bit width.
+ constant vram_1k : integer := 10; --1k = 10 bit width.
+ constant chr_rom_8k : integer := 13; --32k = 15 bit width.
- signal base_clk : std_logic;
signal cpu_clk : std_logic;
signal ppu_clk : std_logic;
+ signal mem_clk : std_logic;
+ signal vga_out_clk : std_logic;
signal rdy, irq_n, nmi_n, dbe, r_nw : std_logic;
signal phi1, phi2 : std_logic;
signal addr : std_logic_vector( addr_size - 1 downto 0);
signal d_io : std_logic_vector( data_size - 1 downto 0);
+ signal rom_ce_n : std_logic;
+ signal ram_ce_n : std_logic;
+ signal ram_oe_n : std_logic;
signal ppu_ce_n : std_logic;
signal apu_ce_n : std_logic;
+
signal rd_n : std_logic;
signal wr_n : std_logic;
signal ale : std_logic;
signal vram_ad : std_logic_vector (7 downto 0);
signal vram_a : std_logic_vector (13 downto 8);
+ signal v_addr : std_logic_vector (13 downto 0);
+ signal nt_v_mirror : std_logic;
+ signal pt_ce_n : std_logic;
+ signal nt0_ce_n : std_logic;
+ signal nt1_ce_n : std_logic;
- signal vga_clk : std_logic;
- signal h_sync_n : std_logic;
- signal v_sync_n : std_logic;
- signal r : std_logic_vector(3 downto 0);
- signal g : std_logic_vector(3 downto 0);
- signal b : std_logic_vector(3 downto 0);
-
- --test...
- signal nmi_n2 : std_logic;
begin
irq_n <= '0';
-
- --- generate base clock.
- clock_p: process
- begin
- base_clk <= '1';
- wait for base_clock_time / 2;
- base_clk <= '0';
- wait for base_clock_time / 2;
- end process;
-
- --- generate test vga clock.
- vga_clock_p : process
- begin
- vga_clk <= '1';
- wait for vga_clk_time / 2;
- vga_clk <= '0';
- wait for vga_clk_time / 2;
- end process;
+ vga_clk <= vga_out_clk;
--ppu/cpu clock generator
clock_inst : clock_divider port map
- (base_clk, rst_n, cpu_clk, ppu_clk);
+ (base_clk, rst_n, cpu_clk, ppu_clk, mem_clk, vga_out_clk);
--mos 6502 cpu instance
cpu_inst : mos6502 generic map (data_size, addr_size)
phi1, phi2, addr, d_io);
addr_dec_inst : address_decoder generic map (addr_size, data_size)
- port map (phi2, r_nw, addr, d_io, ppu_ce_n, apu_ce_n);
+ port map (phi2, mem_clk, r_nw, addr, d_io, rom_ce_n, ram_ce_n, ppu_ce_n, apu_ce_n);
+
+ --main ROM/RAM instance
+ prg_rom_inst : prg_rom generic map (rom_32k, data_size)
+ port map (mem_clk, rom_ce_n, addr(rom_32k - 1 downto 0), d_io);
+
+ ram_oe_n <= not R_nW;
+ prg_ram_inst : ram generic map (ram_2k, data_size)
+ port map (mem_clk, ram_ce_n, ram_oe_n, R_nW, addr(ram_2k - 1 downto 0), d_io);
--nes ppu instance
ppu_inst : ppu
- port map (ppu_clk, ppu_ce_n, rst_n, r_nw, addr(2 downto 0), d_io,
+ port map (ppu_clk, mem_clk, ppu_ce_n, rst_n, r_nw, addr(2 downto 0), d_io,
nmi_n, rd_n, wr_n, ale, vram_ad, vram_a,
- vga_clk, h_sync_n, v_sync_n, r, g, b);
+ vga_out_clk, h_sync_n, v_sync_n, r, g, b);
- ppu_addr_decoder : v_address_decoder generic map (size14, data_size)
- port map (ppu_clk, rd_n, wr_n, ale, vram_ad, vram_a);
+ ppu_addr_decoder : v_address_decoder generic map (vram_size14, data_size)
+ port map (ppu_clk, mem_clk, rd_n, wr_n, ale, v_addr, vram_ad,
+ nt_v_mirror, pt_ce_n, nt0_ce_n, nt1_ce_n);
+ ---VRAM/CHR ROM instances
+ v_addr (13 downto 8) <= vram_a;
+
+ --transparent d-latch
+ vram_latch : ls373 generic map (data_size)
+ port map(ale, '0', vram_ad, v_addr(7 downto 0));
+
+ vchr_rom : chr_rom generic map (chr_rom_8k, data_size)
+ port map (mem_clk, pt_ce_n, v_addr(chr_rom_8k - 1 downto 0), vram_ad, nt_v_mirror);
+
+ --name table/attr table
+ vram_nt0 : ram generic map (vram_1k, data_size)
+ port map (mem_clk, nt0_ce_n, rd_n, wr_n, v_addr(vram_1k - 1 downto 0), vram_ad);
+
+ vram_nt1 : ram generic map (vram_1k, data_size)
+ port map (mem_clk, nt1_ce_n, rd_n, wr_n, v_addr(vram_1k - 1 downto 0), vram_ad);
+
+ --APU/DMA instance
apu_inst : apu
port map (cpu_clk, apu_ce_n, rst_n, r_nw, addr, d_io, rdy);
- dummy_vga_disp : vga_device
- port map (vga_clk, rst_n, h_sync_n, v_sync_n, r, g, b);
-
--- nmi_p: process
--- constant powerup_time : time := 5000 ns;
--- constant reset_time : time := 10 us;
--- begin
--- wait for powerup_time;
--- nmi_n <= '1';
--- wait for reset_time;
--- wait for 46 us;
--- nmi_n <= '0';
---
--- wait;
--- end process;
-
end rtl;
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