Add old files and new gitignore

[clump.git] / cm_processor.v

diff --git a/cm_processor.v b/cm_processor.v
new file mode 100644 (file)
index 0000000..880ee82
--- /dev/null
+++ b/cm_processor.v
@@ -0,0 +1,116 @@
+`include "ram.v"
+
+`define STATE_INIT   3'd0
+`define STATE_READ_A 3'd1
+`define STATE_READ_B 3'd2
+`define STATE_WRITE  3'd3
+
+`define FLAG_NEWS        4'd8
+`define FLAG_CUBE        4'd9
+`define FLAG_ROUTER      4'd10
+`define FLAG_ROUTER_ACK  4'd11
+`define FLAG_DAISY_CHAIN 4'd12
+`define FLAG_LONG_PARITY 4'd13
+`define FLAG_INPUT       4'd14
+`define FLAG_ZERO        4'd15
+
+`define DIRECTION_N  3'd0
+`define DIRECTION_NE 3'd1
+`define DIRECTION_E  3'd2
+`define DIRECTION_SE 3'd3
+`define DIRECTION_S  3'd4
+`define DIRECTION_SW 3'd5
+`define DIRECTION_W  3'd6
+`define DIRECTION_NW 3'd7
+
+module cpu
+  (input clk, input text[54:0],
+   input  cube, input daisy_chain, input pin_input, input router_ack,
+   input [7:0] news_in, output [7:0] news_out,
+   output flag_out, output reg writing_to_router,
+   output mem_in, input mem_out
+);
+
+   wire [3:0]  read_flag = text[30:27];
+   wire [3:0]  write_flag = text[26:23];
+   wire [3:0]  condition_flag = text[22:19];
+   wire           condition_sense = text[18];
+   wire [7:0]  memory_truth_table = text[17:10];
+   wire [7:0]  flag_truth_table = text[9:2];
+   wire [1:0]  news_direction = text[1:0];
+
+   reg [7:0]  general_flags;
+   reg                   news_flag;
+   wire [15:0] flags = {1'd0, pin_input, 1'd0, daisy_chain, router_ack, 1'd0, cube, news_flag, general_flags};
+
+   always @* begin
+         flags[7:0] = general_flags[7:0];
+         case(news_direction)
+               `DIRECTION_NORTH: news_flag = north_in;
+               `DIRECTION_EAST:  news_flag = east_in;
+               `DIRECTION_WEST:  news_flag = west_in;
+               `DIRECTION_SOUTH: news_flag = south_in;
+         endcase // case (news_direction)
+   end
+
+   reg                    alu_in_a;
+   reg                    alu_in_b;
+   reg                    alu_in_f;
+
+   reg                    alu_index;
+
+   reg                    alu_out_memory;
+   reg                    alu_out_flag;
+
+   always @* begin
+         alu_in_f = flags[read_flag];
+         alu_index = (alu_in_a << 2) + (alu_in_b << 1) + alu_in_f;
+
+         alu_out_memory = memory_truth_table[alu_index];
+         alu_out_flag = flag_truth_table[alu_index];
+   end
+
+   assign flag_out = alu_out_flag;
+
+   reg [2:0]   state = `STATE_INIT;
+
+   always @ (posedge clk) begin
+         case (state)
+               `STATE_INIT:
+                 begin
+                        mem_addr <= address_a;
+                        state <= `STATE_READ_A
+                 end
+
+               `STATE_READ_A:
+                 begin
+                        alu_in_a <= mem_out;
+                        mem_addr <= address_b;
+                        mem_write <= 0;
+                        writing_to_router <= 0;
+                        state <= `STATE_READ_B;
+                 end
+
+               `STATE_READ_B:
+                 begin
+                        alu_in_b <= mem_out;
+                        mem_addr <= address_a;
+                        state <= `STATE_WRITE;
+                 end
+
+               `STATE_WRITE:
+                 begin
+                        mem_in <= alu_out_memory;
+                        mem_write <= 1;
+                        state <= `STATE_READ_A;
+
+                        if(!write_flag[3])
+                          general_flags[write_flag[2:0]] <= alu_out_flag;
+
+                        if(write_flag == `FLAG_ROUTER_DATA)
+                          writing_to_router <= 1;
+                 end
+         endcase
+   end
+
+endmodule