github.com/mist-devel.mist-board
1
0
Fork 0
mirror of https://github.com/mist-devel/mist-board.git synced 2026-02-07 00:17:07 +00:00
Code Issues Releases Wiki Activity

[C64] C1541: cosmetics

Browse Source
This commit is contained in:
Gyorgy Szombathelyi
2019-02-05 14:48:37 +01:00
parent 6851298a5e
commit 480ac55a8e
1 changed files with 15 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
cores/c64/rtl/c1541/gcr_floppy.vhd
View File

@@ -158,14 +158,14 @@ with gcr_nibble_out select
X"D" when "11101",--"10111",
X"E" when "11110",--"01111",
X"F" when others; --"10101",
process (clk32)
variable bit_clk_cnt : std_logic_vector(7 downto 0) := (others => '0');
begin
if rising_edge(clk32) then
mode_r1 <= mode;
if (mode_r1 xor mode) = '1' then -- read <-> write change
bit_clk_cnt := (others => '0');
byte_n <= '1';
@@ -178,7 +178,7 @@ begin
else
bit_clk_cnt := bit_clk_cnt + '1';
end if;
byte_n <= '1';
if byte_in_n = '0' and mtr = '1' and ram_ready = '1' then
if bit_clk_cnt > X"10" then
@@ -187,9 +187,7 @@ begin
end if;
end if;
end if;
end if;
end if;
end process;
@@ -201,11 +199,11 @@ begin
if old_track /= track_num then
sector <= (others => '0'); --reset sector number on track change
else if bit_clk_en = '1' then
elsif bit_clk_en = '1' then
mode_r2 <= mode;
if mode = '1' then autorise_write <= '0'; end if;
if (mode xor mode_r2) = '1' then
if mode = '1' then -- leaving write mode
sync_in_n <= '0';
@@ -220,9 +218,9 @@ begin
data_cks <= (others => '0');
end if;
end if;
if sync_in_n = '0' and mode = '1' then
byte_cnt <= (others => '0');
nibble <= '0';
gcr_bit_cnt <= (others => '0');
@@ -230,18 +228,18 @@ begin
c1541_logic_din <= (others => '0');
gcr_byte <= (others => '0');
data_cks <= (others => '0');
if sync_cnt = X"31" then
sync_cnt <= (others => '0');
sync_in_n <= '1';
else
sync_cnt <= sync_cnt + '1';
end if;
end if;
if sync_in_n = '1' or mode = '0' then
gcr_bit_cnt <= gcr_bit_cnt + '1';
if gcr_bit_cnt = X"4" then
gcr_bit_cnt <= (others => '0');
@@ -292,17 +290,17 @@ begin
end if;
end if;
end if;
-- demux byte from floppy (ram)
gcr_byte <= gcr_byte(6 downto 0) & gcr_bit;
if bit_cnt = X"7" then
c1541_logic_din <= gcr_byte(6 downto 0) & gcr_bit;
end if;
-- serialise/convert byte to floppy (ram)
gcr_nibble_out <= gcr_nibble_out(3 downto 0) & gcr_bit_out;
if gcr_bit_cnt = X"0" then
if nibble = '0' then
ram_di(3 downto 0) <= nibble_out;
@@ -318,11 +316,10 @@ begin
else
ram_we <= '0';
end if;
end if;
end if;
end if;
end if;
end process;
end struct;