registers[ 9] <= 0;
registers[10] <= 0;
registers[11] <= 0;
+ ie <= 0;
+ rd <= 1;
+ wr <= 0;
+ newcycle <= 1;
+ state <= 0;
+ cycle <= 0;
end
always @(posedge clk)
case (state)
`STATE_FETCH: begin
- if (wr)
- buswdata <= wdata;
- if (newcycle)
+ if (newcycle) begin
busaddress <= {registers[`REG_PCH], registers[`REG_PCL]};
- else
+ buswr <= 0;
+ busrd <= 1;
+ end else begin
busaddress <= address;
- buswr <= wr;
- busrd <= rd;
+ buswr <= wr;
+ busrd <= rd;
+ if (wr)
+ buswdata <= wdata;
+ end
state <= `STATE_DECODE;
end
`STATE_DECODE: begin
rdata <= busdata;
newcycle <= 0;
cycle <= 0;
- end else
+ end else begin
if (rd) rdata <= busdata;
+ cycle <= cycle + 1;
+ end
buswr <= 0;
busrd <= 0;
wr <= 0;
casex (opcode)
`INSN_LD_reg_imm8:
case (cycle)
- 0: cycle <= 1;
+ 0: begin end
1: case (opcode[5:3])
- `INSN_reg_A: begin registers[`REG_A] <= rdata; cycle <= 0; end
- `INSN_reg_B: begin registers[`REG_B] <= rdata; cycle <= 0; end
- `INSN_reg_C: begin registers[`REG_C] <= rdata; cycle <= 0; end
- `INSN_reg_D: begin registers[`REG_D] <= rdata; cycle <= 0; end
- `INSN_reg_E: begin registers[`REG_E] <= rdata; cycle <= 0; end
- `INSN_reg_H: begin registers[`REG_H] <= rdata; cycle <= 0; end
- `INSN_reg_L: begin registers[`REG_L] <= rdata; cycle <= 0; end
- `INSN_reg_dHL: cycle <= 2;
+ `INSN_reg_A: begin registers[`REG_A] <= rdata; end
+ `INSN_reg_B: begin registers[`REG_B] <= rdata; end
+ `INSN_reg_C: begin registers[`REG_C] <= rdata; end
+ `INSN_reg_D: begin registers[`REG_D] <= rdata; end
+ `INSN_reg_E: begin registers[`REG_E] <= rdata; end
+ `INSN_reg_H: begin registers[`REG_H] <= rdata; end
+ `INSN_reg_L: begin registers[`REG_L] <= rdata; end
+ `INSN_reg_dHL: begin /* Go off to cycle 2 */ end
endcase
- 2: cycle <= 0;
+ 2: begin end
endcase
`INSN_HALT: begin
/* Nothing needs happen here. */
/* XXX Interrupts needed for HALT. */
end
`INSN_LD_HL_reg: begin
- case (cycle)
- 0: cycle <= 1;
- 1: cycle <= 0;
- endcase
+ /* Nothing of interest here */
end
`INSN_LD_reg_HL: begin
case (cycle)
- 0: cycle <= 1;
+ 0: begin end
1: begin
case (opcode[5:3])
`INSN_reg_A: registers[`REG_A] <= tmp;
`INSN_reg_H: registers[`REG_H] <= tmp;
`INSN_reg_L: registers[`REG_L] <= tmp;
endcase
- cycle <= 0;
end
endcase
end
end
`INSN_LD_reg_imm16: begin
case (cycle)
- 0: cycle <= 1;
+ 0: begin /* */ end
1: begin
case (opcode[5:4])
`INSN_reg16_BC: registers[`REG_C] <= rdata;
`INSN_reg16_HL: registers[`REG_L] <= rdata;
`INSN_reg16_SP: registers[`REG_SPL] <= rdata;
endcase
- cycle <= 2;
end
2: begin
case (opcode[5:4])
`INSN_reg16_HL: registers[`REG_H] <= rdata;
`INSN_reg16_SP: registers[`REG_SPH] <= rdata;
endcase
- cycle <= 0;
end
endcase
end
`INSN_LD_SP_HL: begin
case (cycle)
- 0: begin
- cycle <= 1;
- registers[`REG_SPH] <= tmp;
- end
- 1: begin
- cycle <= 0;
- registers[`REG_SPL] <= tmp;
- end
+ 0: registers[`REG_SPH] <= tmp;
+ 1: registers[`REG_SPL] <= tmp;
endcase
end
`INSN_PUSH_reg: begin /* PUSH is 16 cycles! */
case (cycle)
- 0: begin
- {registers[`REG_SPH],registers[`REG_SPL]} <=
- {registers[`REG_SPH],registers[`REG_SPL]} - 1;
- cycle <= 1;
- end
- 1: begin
- {registers[`REG_SPH],registers[`REG_SPL]} <=
- {registers[`REG_SPH],registers[`REG_SPL]} - 1;
- cycle <= 2;
- end
- 2: cycle <= 3;
- 3: cycle <= 0;
+ 0: {registers[`REG_SPH],registers[`REG_SPL]} <=
+ {registers[`REG_SPH],registers[`REG_SPL]} - 1;
+ 1: {registers[`REG_SPH],registers[`REG_SPL]} <=
+ {registers[`REG_SPH],registers[`REG_SPL]} - 1;
+ 2: begin /* type F */ end
+ 3: begin /* type F */ end
endcase
end
`INSN_POP_reg: begin /* POP is 12 cycles! */
case (cycle)
- 0: begin
- cycle <= 1;
- {registers[`REG_SPH],registers[`REG_SPL]} <=
- {registers[`REG_SPH],registers[`REG_SPL]} + 1;
- end
+ 0: {registers[`REG_SPH],registers[`REG_SPL]} <=
+ {registers[`REG_SPH],registers[`REG_SPL]} + 1;
1: begin
case (opcode[5:4])
`INSN_stack_AF: registers[`REG_F] <= rdata;
endcase
{registers[`REG_SPH],registers[`REG_SPL]} <=
{registers[`REG_SPH],registers[`REG_SPL]} + 1;
- cycle <= 2;
end
2: begin
case (opcode[5:4])
`INSN_stack_DE: registers[`REG_D] <= rdata;
`INSN_stack_HL: registers[`REG_H] <= rdata;
endcase
- cycle <= 0;
end
endcase
end
`INSN_LDH_AC: begin
case (cycle)
- 0: cycle <= 1;
- 1: begin
- cycle <= 0;
- if (opcode[4])
- registers[`REG_A] <= rdata;
- end
+ 0: begin /* Type F */ end
+ 1: if (opcode[4])
+ registers[`REG_A] <= rdata;
endcase
end
`INSN_LDx_AHL: begin
case (cycle)
- 0: cycle <= 1;
+ 0: begin /* Type F */ end
1: begin
- cycle <= 0;
if (opcode[3])
registers[`REG_A] <= rdata;
{registers[`REG_H],registers[`REG_L]} <=
`INSN_ALU8: begin
if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0)) begin
/* Sit on our asses. */
- cycle <= 1;
end else begin /* Actually do the computation! */
case (opcode[5:3])
`INSN_alu_ADD: begin
`INSN_NOP: begin /* NOP! */ end
`INSN_RST: begin
case (cycle)
- 0: cycle <= 1;
- 1: cycle <= 2;
- 2: cycle <= 3;
- 3: begin
- cycle <= 0;
- {registers[`REG_SPH],registers[`REG_SPL]} <=
- {registers[`REG_SPH],registers[`REG_SPL]}-2;
- end
+ 0: begin /* type F */ end
+ 1: begin /* type F */ end
+ 2: begin /* type F */ end
+ 3: {registers[`REG_SPH],registers[`REG_SPL]} <=
+ {registers[`REG_SPH],registers[`REG_SPL]}-2;
endcase
end
`INSN_RET: begin
case (cycle)
- 0: cycle <= 1;
- 1: begin
- cycle <= 2;
- registers[`REG_PCL] <= rdata;
- end
- 2: begin
- cycle <= 3;
- registers[`REG_PCH] <= rdata;
- end
+ 0: begin /* type F */ end
+ 1: registers[`REG_PCL] <= rdata;
+ 2: registers[`REG_PCH] <= rdata;
3: begin
- cycle <= 0;
{registers[`REG_SPH],registers[`REG_SPL]} <=
{registers[`REG_SPH],registers[`REG_SPL]} + 2;
if (opcode[4]) /* RETI */
end
`INSN_CALL: begin
case (cycle)
- 0: cycle <= 1;
- 1: begin
- cycle <= 2;
- tmp <= rdata; // tmp contains newpcl
- end
- 2: begin
- cycle <= 3;
- tmp2 <= rdata; // tmp2 contains newpch
- end
- 3: begin
- cycle <= 4;
- end
- 4: begin
- cycle <= 5;
- registers[`REG_PCH] <= tmp2;
- end
+ 0: begin /* type F */ end
+ 1: tmp <= rdata; // tmp contains newpcl
+ 2: tmp2 <= rdata; // tmp2 contains newpch
+ 3: begin /* type F */ end
+ 4: registers[`REG_PCH] <= tmp2;
5: begin
{registers[`REG_SPH],registers[`REG_SPL]} <=
{registers[`REG_SPH],registers[`REG_SPL]} - 2;
registers[`REG_PCL] <= tmp;
- cycle <= 0;
end
endcase
end
end
endmodule
-//module Switches(
-// input [15:0] address,
-// inout [7:0] data,
-// input clk,
-// input wr, rd,
-// input [7:0] switches,
-// output reg [7:0] ledout);
+module Switches(
+ input [15:0] address,
+ inout [7:0] data,
+ input clk,
+ input wr, rd,
+ input [7:0] switches,
+ output reg [7:0] ledout);
-// wire decode = address == 16'hFF51;
-// reg [7:0] odata;
-// wire idata = data;
-// assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
+ wire decode = address == 16'hFF51;
+ reg [7:0] odata;
+ wire idata = data;
+ assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
-// always @(negedge clk)
-// begin
-// if (decode && rd)
-// odata <= switches;
-// else if (decode && wr)
-// ledout <= data;
-// end
-//endmodule
+ always @(negedge clk)
+ begin
+ if (decode && rd)
+ odata <= switches;
+ else if (decode && wr)
+ ledout <= data;
+ end
+endmodule
module CoreTop(
- input iclk,
+ input xtal,
+ input [1:0] switches,
output wire [7:0] leds,
- output serio);
+ output serio,
+ output wire [3:0] digits,
+ output wire [7:0] seven);
wire clk;
- IBUFG ibuf (.O(clk), .I(iclk));
+ //IBUFG ibuf (.O(clk), .I(iclk));
+
+ CPUDCM dcm (.CLKIN_IN(xtal), .CLKFX_OUT(clk));
wire [15:0] addr;
wire [7:0] data;
wire wr, rd;
- wire [7:0] swleds;
-
- assign leds = clk?{rd,wr,addr[5:0]}:data[7:0];
+ wire [7:0] ledout;
+ assign leds = switches[1] ? (switches[0]?{rd,wr,addr[5:0]}:data[7:0])
+ : ledout;
GBZ80Core core(
.clk(clk),
.wr(wr),
.rd(rd));
- assign serio = 0;
+ AddrMon amon(
+ .addr(addr),
+ .clk(clk),
+ .digit(digits),
+ .out(seven)
+ );
+
+ Switches sw(
+ .address(addr),
+ .data(data),
+ .clk(clk),
+ .wr(wr),
+ .rd(rd),
+ .ledout(ledout),
+ .switches(0)
+ );
+
+ UART nouart (
+ .clk(clk),
+ .wr(wr),
+ .rd(rd),
+ .addr(addr),
+ .data(data),
+ .serial(serio)
+ );
endmodule
-//module TestBench();
-// reg clk = 0;
-// wire [15:0] addr;
-// wire [7:0] data;
-// wire wr, rd;
+module TestBench();
+ reg clk = 0;
+ wire [15:0] addr;
+ wire [7:0] data;
+ wire wr, rd;
// wire [7:0] leds;
// wire [7:0] switches;
-// always #10 clk <= ~clk;
-// GBZ80Core core(
-// .clk(clk),
-// .busaddress(addr),
-// .busdata(data),
-// .buswr(wr),
-// .busrd(rd));
+ always #10 clk <= ~clk;
+ GBZ80Core core(
+ .clk(clk),
+ .busaddress(addr),
+ .busdata(data),
+ .buswr(wr),
+ .busrd(rd));
-// ROM rom(
-// .clk(clk),
-// .address(addr),
-// .data(data),
-// .wr(wr),
-// .rd(rd));
+ ROM rom(
+ .clk(clk),
+ .address(addr),
+ .data(data),
+ .wr(wr),
+ .rd(rd));
// InternalRAM ram(
// .address(addr),
// .rd(rd),
// .switches(switches),
// .leds(leds));
-//endmodule
+endmodule
git.joshuawise.com / fpgaboy.git / blobdiff