Files
super6502/hw/efinix_fpga/super6502.sv
2022-12-20 15:38:55 -05:00

56 lines
1.2 KiB
Systemverilog

module super6502
(
input [7:0] cpu_data_in,
input cpu_sync,
input cpu_rwb,
input pll_in,
input button_reset,
input pll_cpu_locked,
input clk_50,
input clk_2,
input logic [15:0] cpu_addr,
output logic [7:0] cpu_data_out,
output logic [7:0] cpu_data_oe,
output logic cpu_irqb,
output logic cpu_nmib,
output logic cpu_rdy,
output logic cpu_resb,
output logic pll_cpu_reset,
output logic cpu_phi2
);
assign pll_cpu_reset = '1;
assign cpu_data_oe = {8{cpu_rwb}};
assign cpu_rdy = '1;
assign cpu_irqb = '1;
assign cpu_nmib = '1;
always @(posedge clk_2) begin
cpu_phi2 <= ~cpu_phi2;
end
always @(posedge clk_2) begin
if (button_reset == '0) begin
cpu_resb <= '0;
end
else begin
if (cpu_resb == '0) begin
cpu_resb <= '1;
end
end
end
efx_single_port_ram boot_rom(
.clk(clk_2), // clock input for one clock mode
.addr(cpu_addr[7:0]), // address input
.wclke('0), // Write clock-enable input
.byteen('0), // Byteen input
.we('0), // Write-enable input
.re(cpu_rwb), // Read-enable input
.rdata(cpu_data_out) // Read data output
);
endmodule