uzix/zx-sizif-512-ext
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fix gs glitches with contended timings

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This commit is contained in:
Eugene Lozovoy
2022-12-18 12:53:09 +03:00
parent 7b2b4350bf
commit 01c9589d64
1 changed files with 21 additions and 6 deletions
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27
cpld/rtl/top.v
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@ -58,6 +58,13 @@ module sizif512_ext(
);
reg n_rd_wr_delayed, n_rd_wr_delayed1;
always @(posedge clk32) begin
n_rd_wr_delayed <= n_rd_wr_delayed1;
n_rd_wr_delayed1 <= n_wr & n_rd;
end
/* MAGIC CONFIGURATION */
reg ym_ena, saa_ena, gs_ena;
always @(posedge clk32 or negedge rst_n) begin
@ -211,20 +218,28 @@ end
reg gs_flag_cmd, gs_flag_data;
wire [7:0] gs_status = {gs_flag_data, 6'b111111, gs_flag_cmd};
always @(posedge clk32) begin
if ((~n_giorq && n_gm1 && ga[3:0] == 4'h2) || (~n_iorq && ~n_rd && port_b3))
always @(posedge clk32 or negedge rst_n) begin
if (!rst_n)
gs_flag_data <= 1'b0;
else if ((~n_giorq && n_gm1 && ga[3:0] == 4'h3) || (~n_iorq && ~n_wr && port_b3))
else if (~n_iorq && ~n_rd && n_rd_wr_delayed && port_b3)
gs_flag_data <= 1'b0;
else if (~n_iorq && ~n_wr && n_rd_wr_delayed && port_b3)
gs_flag_data <= 1'b1;
else if (~n_giorq && n_gm1 && ga[3:0] == 4'h2)
gs_flag_data <= 1'b0;
else if (~n_giorq && n_gm1 && ga[3:0] == 4'h3)
gs_flag_data <= 1'b1;
else if (~n_giorq && n_gm1 && ga[3:0] == 4'hA)
gs_flag_data <= ~gs_reg00[0];
end
always @(posedge clk32) begin
if (~n_giorq && n_gm1 && ga[3:0] == 4'h5)
always @(posedge clk32 or negedge rst_n) begin
if (!rst_n)
gs_flag_cmd <= 1'b0;
else if (~n_iorq && ~n_wr && port_bb)
else if (~n_iorq && ~n_wr && n_rd_wr_delayed && port_bb)
gs_flag_cmd <= 1'b1;
else if (~n_giorq && n_gm1 && ga[3:0] == 4'h5)
gs_flag_cmd <= 1'b0;
else if (~n_giorq && n_gm1 && ga[3:0] == 4'hB)
gs_flag_cmd <= gs_vol3[5];
end