//assign data = rd ? odata : 8'bzzzzzzzz;
endmodule
+module MiniRAM( /* XXX will need to go INSIDE the CPU for when we do DMA */
+ input [15:0] address,
+ inout [7:0] data,
+ input clk,
+ input wr, rd);
+
+ reg [7:0] ram [127:0];
+
+ wire decode = (address >= 16'hFF80) && (address <= 16'hFFFE);
+ reg [7:0] odata;
+ assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
+
+ always @(negedge clk)
+ begin
+ if (decode) // This has to go this way. The only way XST knows how to do
+ begin // block ram is chip select, write enable, and always
+ if (wr) // reading. "else if rd" does not cut it ...
+ ram[address[6:0]] <= data;
+ odata <= ram[address[6:0]];
+ end
+ end
+endmodule
+
module InternalRAM(
input [15:0] address,
inout [7:0] data,
output wire [7:0] seven,
output wire hs, vs,
output wire [2:0] r, g,
- output wire [1:0] b);
+ output wire [1:0] b,
+ output wire soundl, soundr);
wire xtalb, clk, vgaclk;
IBUFG iclkbuf(.O(xtalb), .I(xtal));
.wr(wr),
.rd(rd)
);
+
+ MiniRAM mram(
+ .address(addr),
+ .data(data),
+ .clk(clk),
+ .wr(wr),
+ .rd(rd)
+ );
Timer tmr(
.clk(clk),
.buttons(0),
.master(irq),
.jaddr(jaddr));
+
+ Soundcore sound(
+ .core_clk(clk),
+ .rd(rd),
+ .wr(wr),
+ .addr(addr),
+ .data(data),
+ .snd_data_l(soundl),
+ .snd_data_r(soundr));
endmodule
module TestBench();