Added JTAG interface with testbench

rtl/arch/spartan-6/jtag_if.v

@@ -0,0 +1,34 @@
+`timescale 1ns/1ps
+
+// =============================================================================
+// JTAG interface
+// Spartan-6 BSCAN primitive wrapper (USER1 chain).
+// =============================================================================
+module jtag_if #(
+    parameter chain = 1
+)(
+    input wire i_tdo,
+    output wire o_tck,
+    output wire o_tdi,
+    output wire o_drck,
+    output wire o_capture,
+    output wire o_shift,
+    output wire o_update,
+    output wire o_runtest,
+    output wire o_reset,
+    output wire o_sel
+);
+    BSCAN_SPARTAN6 #(
+        .JTAG_CHAIN(chain)
+    ) bscan_i (
+        .CAPTURE(o_capture),
+        .DRCK(o_drck),
+        .RESET(o_reset),
+        .RUNTEST(o_runtest),
+        .SEL(o_sel),
+        .SHIFT(o_shift),
+        .TCK(o_tck),
+        .TDI(o_tdi),
+        .UPDATE(o_update)
+    );
+endmodule