From ff6351960762343708f1ee822d050dea89b340f4 Mon Sep 17 00:00:00 2001
From: Olof Kindgren <olof.kindgren@gmail.com>
Date: Sun, 18 Nov 2018 21:42:26 +0100
Subject: [PATCH] Temporary hack to blink LED on tinyfpga BX

---
 bench/serv_wrapper.v | 16 +++++++++++++++-
 bitbang.hex          |  4 ++--
 rtl/wb_gpio.v        | 18 ++++++++++++------
 serv.core            |  4 ++--
 4 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/bench/serv_wrapper.v b/bench/serv_wrapper.v
index 0d11cbf..ad0373e 100644
--- a/bench/serv_wrapper.v
+++ b/bench/serv_wrapper.v
@@ -89,10 +89,24 @@ module serv_wrapper
 
    wb_gpio gpio
      (.i_wb_clk (wb_clk),
+      .i_wb_rst (wb_rst),
       .i_wb_dat (wb_m2s_gpio_dat[0]),
       .i_wb_cyc (wb_m2s_gpio_cyc),
       .o_wb_ack (wb_s2m_gpio_ack),
-      .o_gpio   (q));
+      .o_gpio   (/*q*/));
+
+   reg canary;
+
+   always @(posedge wb_clk)
+     if (wb_rst)
+       canary <= 1'b0;
+     /*else if (wb_m2s_cpu_ibus_cyc &
+	      wb_s2m_cpu_ibus_ack &
+	      (wb_m2s_cpu_ibus_adr == 32'h00000020))*/
+     else if (wb_m2s_cpu_dbus_cyc & wb_s2m_cpu_dbus_ack)
+       canary <= ~canary;
+
+   assign q = canary;
 
    assign wb_s2m_gpio_dat = 32'h0;
 
diff --git a/bitbang.hex b/bitbang.hex
index 608e2fc..5dbef99 100644
--- a/bitbang.hex
+++ b/bitbang.hex
@@ -1,5 +1,6 @@
 30000537
-00a00313
+00018337
+6a030313
 00550023
 0012c293
 000073b3
@@ -2045,4 +2046,3 @@ fedff06f
 0
 0
 0
-0
diff --git a/rtl/wb_gpio.v b/rtl/wb_gpio.v
index e3a3642..5759693 100644
--- a/rtl/wb_gpio.v
+++ b/rtl/wb_gpio.v
@@ -1,14 +1,20 @@
 module wb_gpio
   (
    input wire i_wb_clk,
+   input wire i_wb_rst,
    input wire i_wb_dat,
    input wire i_wb_cyc,
-   output reg o_wb_ack = 1'b0,
+   output reg o_wb_ack,
    output reg o_gpio = 1'b0);
    
-   always @(posedge i_wb_clk)
-     if (i_wb_cyc) begin
-	o_wb_ack <= ~o_wb_ack;
-	o_gpio <= i_wb_dat;
-     end
+   always @(posedge i_wb_clk) begin
+      o_wb_ack <= 1'b0;
+      if (i_wb_cyc) begin
+	 if (!o_wb_ack)
+	   o_wb_ack <= 1'b1;
+	 o_gpio <= i_wb_dat;
+      end
+      if (i_wb_rst)
+	o_wb_ack <= 1'b0;
+   end
 endmodule
diff --git a/serv.core b/serv.core
index 9de6e36..70dd1a6 100644
--- a/serv.core
+++ b/serv.core
@@ -66,13 +66,13 @@ targets:
 
   synth:
     default_tool : icestorm
-    filesets : [core, wrapper, pcf]
+    filesets : [core, mem_files, wrapper, pcf]
     generate : [wb_intercon]
     toplevel : serv_wrapper
 
   tinyfpga_bx:
     default_tool : icestorm
-    filesets : [core, wrapper, tinyfpga_bx]
+    filesets : [core, mem_files, wrapper, tinyfpga_bx]
     generate : [wb_intercon]
     tools:
       icestorm: