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Enable writing to the terminal buffer on second port

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This adds an explicit terminal_buffer entity to help with the blockram
inference. Both read and write are completely independent, although they
run with the same clock for now.
This commit is contained in:
Klemens Schölhorn 2018-04-24 21:28:02 +02:00
parent ea99b5b07a
commit 5f47c1327f
5 changed files with 96 additions and 25 deletions
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20
dvi_test.xise
View File

@ -17,7 +17,7 @@
<files>
<file xil_pn:name="vga.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="1"/>
<association xil_pn:name="Implementation" xil_pn:seqID="3"/>
<association xil_pn:name="Implementation" xil_pn:seqID="4"/>
</file>
<file xil_pn:name="vga_test.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="2"/>
@ -27,34 +27,38 @@
</file>
<file xil_pn:name="i2c_master.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="64"/>
<association xil_pn:name="Implementation" xil_pn:seqID="2"/>
<association xil_pn:name="Implementation" xil_pn:seqID="3"/>
</file>
<file xil_pn:name="main.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="65"/>
<association xil_pn:name="Implementation" xil_pn:seqID="8"/>
<association xil_pn:name="Implementation" xil_pn:seqID="9"/>
</file>
<file xil_pn:name="ipcore_dir/clock_source.xaw" xil_pn:type="FILE_XAW">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="106"/>
<association xil_pn:name="Implementation" xil_pn:seqID="5"/>
<association xil_pn:name="Implementation" xil_pn:seqID="6"/>
</file>
<file xil_pn:name="init_ch7301c.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="112"/>
<association xil_pn:name="Implementation" xil_pn:seqID="6"/>
<association xil_pn:name="Implementation" xil_pn:seqID="7"/>
</file>
<file xil_pn:name="main.ucf" xil_pn:type="FILE_UCF">
<association xil_pn:name="Implementation" xil_pn:seqID="0"/>
</file>
<file xil_pn:name="keyboard.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="153"/>
<association xil_pn:name="Implementation" xil_pn:seqID="4"/>
<association xil_pn:name="Implementation" xil_pn:seqID="5"/>
</file>
<file xil_pn:name="ps2.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="154"/>
<association xil_pn:name="Implementation" xil_pn:seqID="1"/>
<association xil_pn:name="Implementation" xil_pn:seqID="2"/>
</file>
<file xil_pn:name="font_rom.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="155"/>
<association xil_pn:name="Implementation" xil_pn:seqID="7"/>
<association xil_pn:name="Implementation" xil_pn:seqID="8"/>
</file>
<file xil_pn:name="terminal_buffer.vhd" xil_pn:type="FILE_VHDL">
<association xil_pn:name="BehavioralSimulation" xil_pn:seqID="156"/>
<association xil_pn:name="Implementation" xil_pn:seqID="1"/>
</file>
</files>

55
font_rom.vhd
View File

@ -13,7 +13,8 @@ entity font_rom is
);
port (
clk: in std_logic;
x, y: in std_logic_vector(9 downto 0);
x: in std_logic_vector(9 downto 0);
y: in std_logic_vector(8 downto 0);
rgb: out std_logic_vector(23 downto 0)
);
@ -40,14 +41,6 @@ architecture logic of font_rom is
constant font: rom_type := read_font("font.hex");
type framebuffer_type is array(0 to 59, 0 to 79) of std_logic_vector(7 downto 0);
constant framebuffer: framebuffer_type := (
0 => (x"48", x"61", x"6C", x"6c", x"6f", others => x"00"),
1 to 59 => (others => x"00")
);
signal char_x: integer range 0 to 79;
signal char_y: integer range 0 to 59;
signal current_char: std_logic_vector(7 downto 0);
signal current_glyph: std_logic_vector(63 downto 0);
@ -56,17 +49,53 @@ architecture logic of font_rom is
constant glyph_pos_length: integer := 2;
type glyph_pos_type is array(1 to glyph_pos_length) of integer range 0 to 63;
signal glyph_pos: glyph_pos_type;
signal write_x: unsigned(6 downto 0);
signal write_y: unsigned(5 downto 0);
signal write_value: std_logic_vector(7 downto 0);
signal ra: std_logic_vector(12 downto 0);
signal wa: std_logic_vector(12 downto 0);
begin
char_x <= to_integer(unsigned(x(9 downto 3)));
char_y <= to_integer(unsigned(y(9 downto 3)));
ra <= x(9 downto 3) & y(8 downto 3);
wa <= std_logic_vector(write_x) & std_logic_vector(write_y);
write_value <= "0" & std_logic_vector(write_x + 32);
cycle_write_location:
process(clk)
constant max_delay: integer := 2000000;
variable delay: integer range 0 to max_delay;
begin
if rising_edge(clk) then
current_char <= framebuffer(char_y, char_x);
if delay = max_delay then
delay := 0;
if write_x = 79 then
write_x <= (others => '0');
if write_y = 59 then
write_y <= (others => '0');
else
write_y <= write_y + 1;
end if;
else
write_x <= write_x + 1;
end if;
else
delay := delay + 1;
end if;
end if;
end process;
end process cycle_write_location;
terminal_buffer: entity work.terminal_buffer port map (
clk => clk,
ra => ra,
do => current_char,
we => '1',
wa => wa,
di => write_value
);
process(clk)
variable current_glyph_pos: integer range 0 to 127;

2
main.vhd
View File

@ -41,7 +41,7 @@ end main;
architecture Behavioral of main is
signal clk_vga: std_logic;
signal image_x: std_logic_vector(9 downto 0);
signal image_y: std_logic_vector(9 downto 0);
signal image_y: std_logic_vector(8 downto 0);
signal pixel_rgb: std_logic_vector(23 downto 0);
signal dvi_clk: std_logic; -- connect vga_sync to dvi_clk_ds
-- tmp

37
terminal_buffer.vhd Normal file
View File

@ -0,0 +1,37 @@
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.numeric_std.all;
entity terminal_buffer is
port (
clk: in std_logic;
we: in std_logic;
wa: in std_logic_vector(12 downto 0);
ra: in std_logic_vector(12 downto 0);
di: in std_logic_vector(7 downto 0);
do: out std_logic_vector(7 downto 0)
);
end terminal_buffer;
architecture syn of terminal_buffer is
type ram_type is array((2**13 - 1) downto 0) of std_logic_vector(7 downto 0);
signal RAM: ram_type;
signal read_a: std_logic_vector(ra'range);
begin
process(clk)
begin
if rising_edge(clk) then
if we = '1' then
RAM(to_integer(unsigned(wa))) <= di;
end if;
read_a <= ra;
end if;
end process;
do <= RAM(to_integer(unsigned(read_a)));
end syn;

7
vga.vhd
View File

@ -7,7 +7,8 @@ entity vga is
port(
clk: in std_logic;
x, y: out std_logic_vector(9 downto 0);
x: out std_logic_vector(9 downto 0);
y: out std_logic_vector(8 downto 0);
pixel_rgb: in std_logic_vector(23 downto 0);
dvi_d: out std_logic_vector(11 downto 0);
@ -21,7 +22,7 @@ end vga;
architecture behavioral of vga is
signal second_batch: std_logic := '0';
signal hcount: std_logic_vector(9 downto 0) := (others => '0');
signal vcount: std_logic_vector(9 downto 0) := (others => '0');
signal vcount: std_logic_vector(8 downto 0) := (others => '0');
signal data_enabled: std_logic;
begin
dvi_clk <= clk;
@ -37,7 +38,7 @@ begin
'1';
x <= hcount when data_enabled = '1' and hcount < 640 else std_logic_vector(to_unsigned(639, 10));
y <= vcount when data_enabled = '1' and vcount < 480 else std_logic_vector(to_unsigned(479, 10));
y <= vcount when data_enabled = '1' and vcount < 480 else std_logic_vector(to_unsigned(479, 9));
data_output: process(clk)
begin