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IremM62: slow down sprite fetching to reserve SDRAM slots to bg fetch

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This commit is contained in:
Gyorgy Szombathelyi 2020-03-12 23:55:36 +01:00
parent d91917d43b
commit 6984dcc5a0
2 changed files with 28 additions and 8 deletions
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32
Arcade_MiST/IremM62 Hardware/rtl/sprite_array.vhd
View File

@ -60,6 +60,7 @@ architecture SYN of sprite_array is
signal ctl_o : ctl_o_a_t(0 to N_SPRITES-1);
signal ld_r : std_logic_vector(N_SPRITES-1 downto 0);
signal ld_en : std_logic;
begin
-- Sprite Data Load Arbiter
@ -78,14 +79,31 @@ begin
elsif rising_edge(clk) and clk_ena = '1' then
if video_ctl.hblank = '0' then
i := 0;
ld_r(ld_r'left) <= '1';
ld_r(ld_r'left-1 downto 0) <= (others => '0');
else
ld_r <= ld_r(ld_r'left-1 downto 0) & ld_r(ld_r'left);
if (i = 31 and hwsel /= HW_HORIZON) or i = N_SPRITES-1 then
i := 0;
ld_r(ld_r'left downto 0) <= (others => '0');
if hwsel = HW_HORIZON then
ld_r(ld_r'left) <= '1';
else
i := i + 1;
ld_r(31) <= '1';
end if;
ld_en <= '1';
else
if hwsel /= HW_HORIZON then
-- there are 128 pixels in HBLANK
-- fetch one word in every pixel clock when 64 sprites/line used (HORIZON)
-- fetch one word in every two pixels when 32 sprites/line in use (every other games)
ld_en <= not ld_en;
end if;
if ld_en = '1' then
if hwsel = HW_HORIZON then
ld_r <= ld_r(ld_r'left-1 downto 0) & ld_r(ld_r'left);
else
ld_r(31 downto 0) <= ld_r(30 downto 0) & ld_r(31);
end if;
if (i = 31 and hwsel /= HW_HORIZON) or i = N_SPRITES-1 then
i := 0;
else
i := i + 1;
end if;
end if;
end if;
row_a <= ctl_o(i).a;

4
Arcade_MiST/IremM62 Hardware/rtl/spritectl.vhd
View File

@ -41,6 +41,7 @@ architecture SYN of spritectl is
alias clk_ena : std_logic is video_ctl.clk_ena;
signal rowStore : std_logic_vector(47 downto 0); -- saved row of spt to show during visibile period
signal ld_r : std_logic;
begin
@ -64,6 +65,7 @@ begin
if rising_edge(clk) then
if clk_ena = '1' then
ld_r <= ctl_i.ld;
if video_ctl.hblank = '1' then
yMat := yMatNext;
else
@ -126,7 +128,7 @@ begin
end if;
end if; -- hblank='0'
if ctl_i.ld = '1' then
if ctl_i.ld = '1' and ld_r = '0' then
xMat := false;
ctl_o.a(4) <= not ctl_o.a(4); -- switch sprite half
if yMat then