From 7a6628f20419ca3bcade1865da66030569feae71 Mon Sep 17 00:00:00 2001
From: uvok
Date: Thu, 1 Jan 2026 16:57:20 +0100
Subject: Add nandgame condition check

---
 nandgame/cond_check.sv    |  23 +++++++++
 nandgame/cond_check_tb.sv | 119 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 142 insertions(+)
 create mode 100644 nandgame/cond_check.sv
 create mode 100644 nandgame/cond_check_tb.sv

diff --git a/nandgame/cond_check.sv b/nandgame/cond_check.sv
new file mode 100644
index 0000000..dc9d334
--- /dev/null
+++ b/nandgame/cond_check.sv
@@ -0,0 +1,23 @@
+// nandgame condition checker
+
+`timescale 1us/1us
+
+module  cond_check #(
+  parameter DATA_WIDTH = 16
+) (
+  input [(DATA_WIDTH-1):0] X,
+  input wire ltz,
+  input wire eqz,
+  input wire gtz,
+  output wire res
+);
+
+wire ltr, eqr, gtr, greater_zero;
+assign greater_zero = X[(DATA_WIDTH - 1)] == 0;
+assign ltr = ltz && !greater_zero;
+assign gtr = gtz && greater_zero && !(X == 0);
+assign eqr = eqz && (X == 0);
+
+assign res = ltr || gtr || eqr;
+
+endmodule
diff --git a/nandgame/cond_check_tb.sv b/nandgame/cond_check_tb.sv
new file mode 100644
index 0000000..a7a22dc
--- /dev/null
+++ b/nandgame/cond_check_tb.sv
@@ -0,0 +1,119 @@
+`timescale 1us/1us
+
+`include "nandgame_types.v"
+
+module cond_check_tb;
+
+logic [15:0] in1;
+logic ltz, gtz, eqz;
+logic res;
+
+cond_check uut (
+  .X(in1),
+  .ltz(ltz),
+  .gtz(gtz),
+  .eqz(eqz),
+  .res(res)
+);
+
+string filename;
+initial begin
+`ifdef DUMP_FILE_NAME
+  filename=`DUMP_FILE_NAME;
+`else
+  filename="cond_check.lin1t2";
+`endif
+  $dumpfile(filename); $dumpvars();
+
+end
+
+bit exp_res;
+initial begin
+  eqz = 0; gtz = 0; ltz = 0;  in1 = 0;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 0; ltz = 1;  in1 = 0;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 1; ltz = 0;  in1 = 0;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 1; gtz = 0; ltz = 0;  in1 = 0;
+  #1
+  exp_res = 1;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 0; ltz = 0;  in1 = 1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 0; ltz = 1;  in1 = 1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 1; ltz = 0;  in1 = 1;
+  #1
+  exp_res = 1;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 1; gtz = 0; ltz = 0;  in1 = 1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 0; ltz = 0; in1 = -1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 0; ltz = 1; in1 = -1;
+  #1
+  exp_res = 1;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 0; gtz = 1; ltz = 0; in1 = -1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  eqz = 1; gtz = 0; ltz = 0; in1 = -1;
+  #1
+  exp_res = 0;
+  assert(res == exp_res)
+  else $error("Expected %d, but got %d", exp_res, res);
+  #1
+
+  $finish();
+end
+
+endmodule
-- 
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