Files
rmonic79 d6d7cb3155 ChinaGate_MiSTer v1.0 — first public release
FPGA core for China Gate (Technos Japan, 1988) on MiSTer.
Full game with audio, 2 ROM sets (US + JP), pause overlay
with logo + supporters scroll, MiSTer OSD audio mixer.

ROM sets:
  - China Gate (US)              — chinagat
  - Sai Yu Gou Ma Roku (Japan)   — saiyugou (alternative)

Hardware: 2x HD63C09 main+sub @ 1.5MHz, Z80 sound @ 3.579545MHz,
YM2151 + OKI M6295. Resolution 256x240 @ 57Hz.

License: GPL-3.0-or-later
2026-05-06 08:33:41 +02:00

110 lines
1.9 KiB
Systemverilog

// result = num/div
module sys_udiv
#(
parameter NB_NUM,
parameter NB_DIV
)
(
input clk,
input start,
output busy,
input [NB_NUM-1:0] num,
input [NB_DIV-1:0] div,
output reg [NB_NUM-1:0] result,
output reg [NB_DIV-1:0] remainder
);
reg run;
assign busy = run;
always @(posedge clk) begin
reg [5:0] cpt;
reg [NB_NUM+NB_DIV+1:0] rem;
if (start) begin
cpt <= 0;
run <= 1;
rem <= num;
end
else if (run) begin
cpt <= cpt + 1'd1;
run <= (cpt != NB_NUM + 1'd1);
remainder <= rem[NB_NUM+NB_DIV:NB_NUM+1];
if (!rem[NB_DIV + NB_NUM + 1'd1])
rem <= {rem[NB_DIV+NB_NUM:0] - (div << NB_NUM),1'b0};
else
rem <= {rem[NB_DIV+NB_NUM:0] + (div << NB_NUM),1'b0};
result <= {result[NB_NUM-2:0], !rem[NB_DIV + NB_NUM + 1'd1]};
end
end
endmodule
// result = mul1*mul2
module sys_umul
#(
parameter NB_MUL1,
parameter NB_MUL2
)
(
input clk,
input start,
output busy,
input [NB_MUL1-1:0] mul1,
input [NB_MUL2-1:0] mul2,
output reg [NB_MUL1+NB_MUL2-1:0] result
);
reg run;
assign busy = run;
always @(posedge clk) begin
reg [NB_MUL1+NB_MUL2-1:0] add;
reg [NB_MUL2-1:0] map;
if (start) begin
run <= 1;
result <= 0;
add <= mul1;
map <= mul2;
end
else if (run) begin
if(!map) run <= 0;
if(map[0]) result <= result + add;
add <= add << 1;
map <= map >> 1;
end
end
endmodule
// result = (mul1*mul2)/div
module sys_umuldiv
#(
parameter NB_MUL1,
parameter NB_MUL2,
parameter NB_DIV
)
(
input clk,
input start,
output busy,
input [NB_MUL1-1:0] mul1,
input [NB_MUL2-1:0] mul2,
input [NB_DIV-1:0] div,
output [NB_MUL1+NB_MUL2-1:0] result,
output [NB_DIV-1:0] remainder
);
wire mul_run;
wire [NB_MUL1+NB_MUL2-1:0] mul_res;
sys_umul #(NB_MUL1,NB_MUL2) umul(clk,start,mul_run,mul1,mul2,mul_res);
sys_udiv #(NB_MUL1+NB_MUL2,NB_DIV) udiv(clk,start|mul_run,busy,mul_res,div,result,remainder);
endmodule