try to implement comb_mem

1 files changed, 56 insertions, 0 deletions

diff --git a/nandgame/comb_mem.sv b/nandgame/comb_mem.sv
new file mode 100644
index 0000000..bbfdcd0
--- /dev/null
+++ b/nandgame/comb_mem.sv
@@ -0,0 +1,56 @@
+`timescale 1us/1us
+
+`include "../my_mem.v"
+
+module comb_mem #(
+  parameter DATA_WIDTH = 16
+) (
+    // store to A register
+    input a_i,
+    // store to D register
+    input d_i,
+    // store to address in memory pointed to by A (currently)
+    input pa_i,
+
+    // value to store
+    input [(DATA_WIDTH-1):0] X,
+    // nandgame updates on falling edge
+    input wire cl,
+
+    output reg [(DATA_WIDTH-1):0] A_o,
+    output reg [(DATA_WIDTH-1):0] D_o,
+    output reg [(DATA_WIDTH-1):0] pA_o
+);
+
+wire inv_clk;
+// my hw uses posedge, nandgame uses negedge.
+assign inv_clk = ~cl;
+
+my_mem #(
+    .DATA_WIDTH(DATA_WIDTH),
+    // limit memory
+    .DATA_DEPTH(1024)
+) nand_memory (
+    .clk_i(inv_clk),
+    .write_en_i(pa_i),
+    .read_en_i(1'b1),
+    .r_read_addr(A_o),
+    .r_write_addr(A_o),
+    .data_o(pA_o),
+    .data_i(X)
+);
+
+initial begin
+    A_o = 0;
+    D_o = 0;
+end
+
+always @(negedge cl) begin
+    if (a_i)
+        A_o <= X;
+
+    if (d_i)
+        D_o <= X;
+end
+
+endmodule