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[C64] CIA: fix flag_n input

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This commit is contained in:
Gyorgy Szombathelyi
2019-02-12 11:27:46 +01:00
parent 3f714e2ca4
commit a73a7caad2
1 changed files with 9 additions and 5 deletions
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14
cores/c64/rtl/mos6526.v
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@@ -1,8 +1,7 @@
// MOS6526
// by Rayne
// Timers & Interrupts are rewritten by slingshot
// Passes all CIA Timer tests
// TODO: check if Flag and Serial port interrupts are still working
// Passes all Lorenz CIA Timer tests
module mos6526 (
input wire mode, // 0 - 6526 "old", 1 - 8521 "new"
@@ -153,9 +152,14 @@ end
// FLAG Input
always @(posedge clk) begin
if (!res_n || int_reset) icr[4] <= 1'b0;
else if (!flag_n && flag_n_prev) icr[4] <= 1'b1;
if (phi2_p) flag_n_prev <= flag_n;
if (!res_n) icr[4] <= 1'b0;
else begin
if (!flag_n && flag_n_prev) icr[4] <= 1'b1;
if (phi2_p) begin
flag_n_prev <= flag_n;
if (int_reset) icr[4] <= 1'b0;
end
end
end
// Port Control Output