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C64: [C1541] Fix VIA Timer A irq generation + PB output

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This commit is contained in:
Gyorgy Szombathelyi
2020-04-13 16:40:58 +02:00
parent 29d579eada
commit 8bc755a1fe
1 changed files with 10 additions and 7 deletions
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17
cores/c64/rtl/c1541/via6522.vhd
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@@ -343,6 +343,9 @@ begin
when X"0" => -- ORB
--Port B reads its own output register for pins set to output.
data_out <= (pio_i.prb and pio_i.ddrb) or (irb and not pio_i.ddrb);
if tmr_a_output_en='1' then
data_out(7) <= timer_a_out;
end if;
when X"1" => -- ORA
data_out <= ira;
when X"2" => -- DDRB
@@ -437,8 +440,8 @@ begin
-- Timer A
tmr_a: block
signal timer_a_reload : std_logic;
signal timer_a_oneshot_trig : std_logic;
signal timer_a_toggle : std_logic;
signal timer_a_may_interrupt : std_logic;
begin
process(clock)
begin
@@ -449,7 +452,7 @@ begin
if timer_a_reload = '1' then
timer_a_count <= timer_a_latch;
timer_a_reload <= '0';
timer_a_oneshot_trig <= '0';
timer_a_may_interrupt <= timer_a_may_interrupt and tmr_a_freerun;
else
if timer_a_count = X"0000" then
-- generate an event if we were triggered
@@ -461,29 +464,29 @@ begin
end if;
if rising = '1' then
if timer_a_event = '1' then
if timer_a_event = '1' and tmr_a_output_en = '1' then
timer_a_toggle <= not timer_a_toggle;
end if;
end if;
if write_t1c_h = '1' then
timer_a_toggle <= '0';
timer_a_may_interrupt <= '1';
timer_a_toggle <= not tmr_a_output_en;
timer_a_count <= data_in & timer_a_latch(7 downto 0);
timer_a_reload <= '0';
timer_a_oneshot_trig <= '1';
end if;
if reset='1' then
timer_a_may_interrupt <= '0';
timer_a_toggle <= '1';
timer_a_count <= latch_reset_pattern;
timer_a_reload <= '0';
timer_a_oneshot_trig <= '0';
end if;
end if;
end process;
timer_a_out <= timer_a_toggle;
timer_a_event <= rising and timer_a_reload and (tmr_a_freerun or timer_a_oneshot_trig);
timer_a_event <= rising and timer_a_reload and timer_a_may_interrupt;
end block tmr_a;