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corax+

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Nicholas Orlowsky 2024-01-31 11:04:55 -06:00
parent 1c16da9ed9
commit 55f965625f
6 changed files with 139 additions and 28 deletions
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1
README.md
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@ -45,3 +45,4 @@ yayacemu [PATH_TO_YOUR_ROM]
![Chip 8 Logo Demo](https://github.com/nickorlow/yayacemu/blob/main/screenshots/chip8-logo.png?raw=true)
![IBM Logo Demo](https://github.com/nickorlow/yayacemu/blob/main/screenshots/ibm-logo.png?raw=true)
![CORAX+ Test Demo](https://github.com/nickorlow/yayacemu/blob/main/screenshots/corax.png?raw=true)

3
rom_loader.sv
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@ -14,10 +14,11 @@ module rom_loader (
rom_size = load_rom();
$display("HW : ROM size is %0d bytes (%0d bits) (%0d instructions)", rom_size, rom_size * 8, rom_size / 2);
for (i = 0; i < rom_size; i++) begin
memory[i] = get_next_instr();
memory['h200 + i] = get_next_instr();
end
close_rom();
$display("HW : ROM loaded successfully");
$finish;
rom_ready = 1;
end
endmodule

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tests/3-corax+.ch8 Normal file
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6
yayacemu.cpp
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@ -89,16 +89,14 @@ int main(int argc, char** argv) {
contextp->commandArgs(argc, argv);
Vyayacemu* top = new Vyayacemu{contextp};
//while (!contextp->gotFinish()) {
top->pc_out = 0;
while (top->pc_out < 100) {
for (int i = 0; i < 20000; i++) {
top->clk_in ^= 1;
top->pc_in = top->pc_out;
top->eval();
usleep(500);
}
printf("TB : Testbench has reached end of simulation. Pausing for 10 seconds before exiting");
fflush(stdout);
usleep(10000000);
usleep(3000000);
delete top;
delete contextp;
return 0;

157
yayacemu.sv
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@ -1,39 +1,44 @@
module yayacemu (
input wire clk_in,
input int pc_in,
output int pc_out
input wire clk_in
);
import "DPI-C" function void init_screen();
wire [31:0] vram [0:2047];
bit [7:0] memory [0:4095];
wire [7:0] registers [0:15];
logic [7:0] index_reg;
logic [3:0] stack_pointer;
wire [15:0] stack [0:15];
logic [15:0] index_reg;
logic rom_ready;
int pc;
logic [15:0] program_counter;
rom_loader rl (memory, rom_ready);
chip8_cpu cpu (memory, clk_in, vram, index_reg, registers, pc_in, pc_out);
chip8_cpu cpu (memory, clk_in, vram, stack, index_reg, stack_pointer, registers, program_counter);
chip8_gpu gpu (vram);
initial begin
program_counter = 'h200;
stack_pointer = 4'b0000;
init_screen();
end
endmodule
module chip8_cpu(
input bit [7:0] memory [0:4095],
output bit [7:0] memory [0:4095],
input wire clk_in,
output wire [31:0] vram [0:2047],
output wire [7:0] index_reg,
output wire [15:0] stack [0:15],
output wire [15:0] index_reg,
output wire [3:0] stack_pointer,
output wire [7:0] registers [0:15],
input int pc_in,
output int pc_out
output wire [15:0] program_counter
);
logic [15:0] opcode;
logic [15:0] scratch;
logic [15:0] scratch2;
logic [31:0] x_cord;
logic [31:0] y_cord;
@ -42,13 +47,14 @@ module chip8_cpu(
logic [7:0] sprite_pixel;
int i;
logic [7:0] i8;
int r;
int c;
always_ff @(posedge clk_in) begin
opcode = {memory[pc_in], memory[pc_in+1]};
opcode = {memory[program_counter+0], memory[program_counter+1]};
$display("HW : opcode is 0x%h (%b)", opcode, opcode);
$display("HW : PC %0d", pc_in);
$display("HW : PC %0d 0x%h", program_counter, program_counter);
casez(opcode)
'h00E0: begin
@ -57,10 +63,42 @@ module chip8_cpu(
vram[i] = 0;
end
end
'h00EE: $display("HW : INSTR RET");
'h0???: $display("HW : INSTR SYS addr");
'h1???: $display("HW : INSTR JP addr");
'h2???: $display("HW : INSTR CALL addr");
'h00EE: begin
$display("HW : INSTR RET");
stack_pointer--;
program_counter = stack[stack_pointer];
end
'h0???: $display("HW : INSTR SYS addr (Treating as NOP)");
'h1???: begin
$display("HW : INSTR JP addr");
program_counter = (opcode & 'h0FFF) - 2;
end
'h2???: begin
$display("HW : INSTR CALL addr");
stack[stack_pointer] = program_counter;
stack_pointer++;
program_counter = (opcode & 'h0FFF) - 2;
end
'h3???: begin
$display("HW : INSTR SE Vx, byte");
scratch = (opcode & 'h00FF);
if (scratch[7:0] == registers[(opcode & 'h0F00) >> 8]) begin
program_counter += 2;
end
end
'h4???: begin
$display("HW : INSTR SNE Vx, byte");
scratch = (opcode & 'h00FF);
if (scratch[7:0] != registers[(opcode & 'h0F00) >> 8]) begin
program_counter += 2;
end
end
'h5??0: begin
$display("HW : INSTR SE Vx, Vy");
if (registers[(opcode & 'h00F0) >> 4] == registers[(opcode & 'h0F00) >> 8]) begin
program_counter += 2;
end
end
'h6???: begin
$display("HW : INSTR LD Vx, byte");
scratch = (opcode & 'h00FF);
@ -71,37 +109,110 @@ module chip8_cpu(
scratch = (opcode & 'h00FF);
registers[(opcode & 'h0F00) >> 8] += scratch[7:0];
end
'h8??0: begin
$display("HW : INSTR LD Vx, Vy");
registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4];
end
'h8??1: begin
$display("HW : INSTR OR Vx, Vy");
registers[(opcode & 'h0F00) >> 8] |= registers[(opcode & 'h00F0) >> 4];
end
'h8??2: begin
$display("HW : INSTR AND Vx, Vy");
registers[(opcode & 'h0F00) >> 8] &= registers[(opcode & 'h00F0) >> 4];
end
'h8??3: begin
$display("HW : INSTR XOR Vx, Vy");
registers[(opcode & 'h0F00) >> 8] ^= registers[(opcode & 'h00F0) >> 4];
end
'h8??4: begin
$display("HW : INSTR ADD Vx, Vy");
registers[(opcode & 'h0F00) >> 8] += registers[(opcode & 'h00F0) >> 4];
end
'h8??5: begin
$display("HW : INSTR SUB Vx, Vy");
registers[(opcode & 'h0F00) >> 8] -= registers[(opcode & 'h00F0) >> 4];
end
'h8??6: begin
$display("HW : INSTR SHR Vx {, Vy}");
registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4]>> 1;
end
'h8??7: begin
$display("HW : INSTR SUBN Vx, Vy");
registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4] - registers[(opcode & 'h0F00) >> 8];
end
'h8??E: begin
$display("HW : INSTR SHL Vx {, Vy}");
registers[(opcode & 'h0F00) >> 8] = registers[(opcode & 'h00F0) >> 4]<< 1;
end
'hA???: begin
$display("HW : INSTR LD I, addr");
scratch = (opcode & 'h0FFF);
index_reg = scratch[7:0];
index_reg = (opcode & 'h0FFF);
end
'hD???: begin
$display("HW : INSTR DRW Vx, Vy, nibble");
x_cord = {24'h000000, registers[(opcode & 'h0F00) >> 8]};
y_cord = {24'h000000, registers[(opcode & 'h00F0) >> 4]};
x_cord %= 64;
y_cord %= 32;
scratch = (opcode & 'h000F);
size = scratch[7:0];
registers[15] = 0;
for (r = 0; r < size; r++) begin
for ( c = 0; c < 8; c++) begin
screen_pixel = vram[((r + y_cord) * 64) + (x_cord + c)];
sprite_pixel = memory[{24'h000000, index_reg} + r] & ('h80 >> c);
sprite_pixel = memory[{16'h0000, index_reg} + r] & ('h80 >> c);
if (|sprite_pixel) begin
if (screen_pixel == 32'hFFFFFFFF) begin
registers[15] = 1;
end
vram[((r + y_cord) * 64) + (x_cord + c)] = screen_pixel ^ 32'hFFFFFFFF;
vram[((r + y_cord) * 64) + (x_cord + c)] ^= 32'hFFFFFFFF;
end
end
end
end
end
end
'hF?33: begin
$display("HW : INSTR LD B, Vx");
scratch = {8'h00, registers[(opcode & 'h0F00) >> 8]};
scratch2 = scratch % 10;
memory[index_reg + 2] = scratch2[7:0];
scratch /= 10;
scratch2 = scratch % 10;
memory[index_reg + 1] = scratch2[7:0];
scratch /= 10;
scratch2 = scratch % 10;
memory[index_reg + 0] = scratch2[7:0];
end
'hF?55: begin
$display("HW : INSTR LD [I], Vx");
scratch = (opcode & 'h0F00) >> 8;
for (i8 = 0; i8 <= scratch[7:0]; i8++) begin
scratch2 = index_reg + {8'h00, i8};
memory[scratch2[11:0]] = registers[i8[3:0]];
end
index_reg++;
end
'hF?65: begin
$display("HW : INSTR LD Vx, [I]");
scratch = (opcode & 'h0F00) >> 8;
for (i8 = 0; i8 <= scratch[7:0]; i8++) begin
scratch2 = index_reg + {8'h00, i8};
registers[i8[3:0]] = memory[scratch2[11:0]];
end
index_reg++;
end
'hF?1E: begin
$display("HW : INSTR ADD I, Vx");
index_reg = index_reg + {8'h00, registers[(opcode & 'h0F00) >> 8]};
end
default: $display("HW : ILLEGAL INSTRUCTION");
endcase
pc_out <= pc_in + 2;
program_counter += 2;
end
endmodule