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IremM62: fix CPU interrupt

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This commit is contained in:
Gyorgy Szombathelyi 2020-03-07 22:44:06 +01:00
parent 3d8c538e98
commit 033877c832
1 changed files with 19 additions and 31 deletions
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50
Arcade_MiST/IremM62 Hardware/rtl/platform.vhd
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@ -86,6 +86,7 @@ architecture SYN of platform is
signal cpu_io_rd : std_logic;
signal cpu_io_wr : std_logic;
signal cpu_irq : std_logic;
signal cpu_intack : std_logic;
-- ROM signals
signal rom_cs : std_logic;
@ -301,7 +302,7 @@ begin
intreq => cpu_irq,
intvec => cpu_d_i,
intack => open,
intack => cpu_intack,
nmi => '0'
);
@ -359,41 +360,28 @@ begin
BLK_INTERRUPTS : block
signal vblank_int : std_logic;
signal vblank_r : std_logic;
begin
process (clk_sys, rst_sys)
variable vblank_r : std_logic_vector(3 downto 0);
alias vblank_prev : std_logic is vblank_r(vblank_r'left);
alias vblank_um : std_logic is vblank_r(vblank_r'left-1);
-- 1us duty for VBLANK_INT
variable count : integer range 0 to CLK0_FREQ_MHz * 100;
begin
if rst_sys = '1' then
vblank_int <= '0';
vblank_r := (others => '0');
count := count'high;
elsif rising_edge(clk_sys) then
-- rising edge vblank only
if vblank_prev = '0' and vblank_um = '1' then
count := 0;
end if;
if count /= count'high then
vblank_int <= '1';
count := count + 1;
else
vblank_int <= '0';
end if;
vblank_r := vblank_r(vblank_r'left-1 downto 0) & graphics_i.vblank;
end if; -- rising_edge(clk_sys)
end process;
-- generate INT
cpu_irq <= vblank_int;
process (clk_sys, rst_sys)
begin
if rst_sys = '1' then
cpu_irq <= '0';
elsif rising_edge(clk_sys) then
vblank_r <= graphics_i.vblank;
if vblank_r = '0' and graphics_i.vblank = '1' then
cpu_irq <= '1';
end if;
if cpu_intack = '1' then
cpu_irq <= '0';
end if;
end if;
end process;
end block BLK_INTERRUPTS;
BLK_INPUTS : block
begin
in_d_o <= inputs_i(0).d when cpu_a(2 downto 0) = "000" else