diff options
Diffstat (limited to 'basys3/basys3.srcs/ppu_pceg.vhd')
-rw-r--r-- | basys3/basys3.srcs/ppu_pceg.vhd | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/basys3/basys3.srcs/ppu_pceg.vhd b/basys3/basys3.srcs/ppu_pceg.vhd index 5d9f4d6..d53d86a 100644 --- a/basys3/basys3.srcs/ppu_pceg.vhd +++ b/basys3/basys3.srcs/ppu_pceg.vhd @@ -5,34 +5,36 @@ use work.ppu_consts.all; entity ppu_pceg is port( CLK : in std_logic; -- system clock RESET : in std_logic; -- async reset - SPRITE : out std_logic; -- sprite info fetch + sprite pixel fetch + SPRITE_BG : out std_logic; -- sprite info fetch + sprite pixel fetch + SPRITE_FG : out std_logic; -- sprite pixel fetch DONE : out std_logic; -- last pipeline stage done READY : out std_logic); -- rgb buffer propagation ready end ppu_pceg; architecture Behavioral of ppu_pceg is - type states is (PL_SPRITE, PL_DONE, PL_READY); - signal state : states := PL_SPRITE; + signal PL_SPRITE_BG, PL_SPRITE_FG, PL_DONE, PL_READY : boolean := false; begin -- output drivers - SPRITE <= CLK when RESET = '0' and state = PL_SPRITE else '0'; - DONE <= CLK when RESET = '0' and state = PL_DONE else '0'; - READY <= '1' when RESET = '0' and state = PL_READY else '0'; + SPRITE_BG <= CLK when RESET = '0' and PL_SPRITE_BG else '0'; + SPRITE_FG <= CLK when RESET = '0' and PL_SPRITE_FG else '0'; + DONE <= CLK when RESET = '0' and PL_DONE else '0'; + READY <= '1' when RESET = '0' and PL_READY else '0'; process(CLK, RESET) variable CLK_IDX : natural range 0 to PPU_PL_TOTAL_STAGES+1 := 0; begin if RESET = '1' then - state <= PL_SPRITE; + CLK_IDX := 0; + PL_SPRITE_BG <= false; + PL_SPRITE_FG <= false; + PL_DONE <= false; + PL_READY <= false; elsif rising_edge(CLK) then -- clock counter ranges - if CLK_IDX < 4 then - state <= PL_SPRITE; - elsif CLK_IDX < 5 then - state <= PL_DONE; - else - state <= PL_READY; - end if; + PL_SPRITE_BG <= true when CLK_IDX >= 0 and CLK_IDX <= 3 else false; + PL_SPRITE_FG <= true when CLK_IDX >= 1 and CLK_IDX <= 2 else false; + PL_DONE <= true when CLK_IDX = 4 else false; + PL_READY <= true when CLK_IDX >= 5 else false; -- increment clock counter CLK_IDX := CLK_IDX + 1; |