diff --git a/spiOverJtag/Makefile b/spiOverJtag/Makefile
index 49557d2..b05e267 100644
--- a/spiOverJtag/Makefile
+++ b/spiOverJtag/Makefile
@@ -1,4 +1,4 @@
-XILINX_PARTS := xc6slx16ftg256 xc6slx16csg324 xc6slx45csg324 xc6slx100fgg484 \
+XILINX_PARTS := xc3s500evq100 xc6slx16ftg256 xc6slx16csg324 xc6slx45csg324 xc6slx100fgg484 \
 	xc6slx150tfgg484 \
 	xc7a35tcpg236 xc7a35tcsg324 xc7a35tftg256 \
 	xc7a50tcpg236 xc7a75tfgg484 xc7a100tcsg324 xc7a100tfgg484 xc7a200tsbg484 \
diff --git a/spiOverJtag/build.py b/spiOverJtag/build.py
index c8bb554..33af234 100755
--- a/spiOverJtag/build.py
+++ b/spiOverJtag/build.py
@@ -44,12 +44,18 @@ elif subpart == "xc7s":
 elif subpart == "xc6s":
     family = "Spartan6"
     tool = "ise"
+    speed = -3
+elif subpart == "xc3s":
+    family = "Spartan3E"
+    tool = "ise"
+    speed = -4
 else:
     print("Error: unknown device")
     os.sys.exit()
 
 if tool in ["ise", "vivado"]:
     pkg_name = {
+        "xc3s500evq100"    : "xc3s_vq100",
         "xc6slx16ftg256"   : "xc6s_ftg256",
         "xc6slx16csg324"   : "xc6s_csg324",
         "xc6slx45csg324"   : "xc6s_csg324",
@@ -73,18 +79,20 @@ if tool in ["ise", "vivado"]:
         cst_type = "UCF"
         tool_options = {'family': family,
                         'device': {
+                            "xc3s500evq100": "xc3s500e",
                             "xc6slx16ftg256": "xc6slx16",
                             "xc6slx16csg324": "xc6slx16",
                             "xc6slx45csg324": "xc6slx45",
                             "xc6slx100fgg484": "xc6slx100",
                             "xc6slx150tfgg484": "xc6slx150t"}[part],
                         'package': {
+                            "xc3s500evq100": "vq100",
                             "xc6slx16ftg256": "ftg256",
                             "xc6slx16csg324": "csg324",
                             "xc6slx45csg324": "csg324",
                             "xc6slx100fgg484": "fgg384",
                             "xc6slx150tfgg484": "fgg484"}[part],
-                        'speed' : -3
+                        'speed' : speed
                 }
     else:
         cst_type = "xdc"
diff --git a/spiOverJtag/constr_xc3s_vq100.ucf b/spiOverJtag/constr_xc3s_vq100.ucf
new file mode 100644
index 0000000..14ce462
--- /dev/null
+++ b/spiOverJtag/constr_xc3s_vq100.ucf
@@ -0,0 +1,5 @@
+NET "sdi_dq0"  LOC = P27 | IOSTANDARD = LVCMOS33;
+NET "sdo_dq1"  LOC = P44 | IOSTANDARD = LVCMOS33;
+NET "csn"      LOC = P24 | IOSTANDARD = LVCMOS33;
+NET "sck"      LOC = P50 | IOSTANDARD = LVCMOS33;
+
diff --git a/spiOverJtag/spiOverJtag_xc3s500evq100.bit.gz b/spiOverJtag/spiOverJtag_xc3s500evq100.bit.gz
new file mode 100644
index 0000000..0326c0e
Binary files /dev/null and b/spiOverJtag/spiOverJtag_xc3s500evq100.bit.gz differ
diff --git a/spiOverJtag/xilinx_spiOverJtag.v b/spiOverJtag/xilinx_spiOverJtag.v
index 8730967..e982489 100644
--- a/spiOverJtag/xilinx_spiOverJtag.v
+++ b/spiOverJtag/xilinx_spiOverJtag.v
@@ -1,8 +1,12 @@
 module spiOverJtag
 (
 	output csn,
+
 `ifdef spartan6
 	output sck,
+`endif
+`ifdef spartan3e
+	output sck,
 `endif
 	output sdi_dq0,
 	input  sdo_dq1,
@@ -41,6 +45,10 @@ module spiOverJtag
 
 `ifdef spartan6
 	assign sck = drck;
+`else
+`ifdef spartan3e
+	assign sck = drck;
+	assign runtest = tmp_up_s;
 `else
 	STARTUPE2 #(
 		.PROG_USR("FALSE"),  // Activate program event security feature. Requires encrypted bitstreams.
@@ -61,7 +69,27 @@ module spiOverJtag
 		.USRDONETS(1'b1)  // 1-bit input: User DONE 3-state enable output
 	);
 `endif
+`endif
 
+`ifdef spartan3e
+	BSCAN_SPARTAN3 bscane2_inst (
+		.CAPTURE(capture), // 1-bit output: CAPTURE output from TAP controller.
+		.DRCK1	(drck),    // 1-bit output: Gated TCK output. When SEL
+						   //               is asserted, DRCK toggles when
+						   //               CAPTURE or SHIFT are asserted.
+		.DRCK2  (),        // 1-bit output: USER2 function
+		.RESET  (),        // 1-bit output: Reset output for TAP controller.
+		.SEL1   (sel),     // 1-bit output: USER1 instruction active output.
+		.SEL2   (),        // 1-bit output: USER2 instruction active output.
+		.SHIFT  (),        // 1-bit output: SHIFT output from TAP controller.
+		.TDI    (tdi),     // 1-bit output: Test Data Input (TDI) output
+		                   //               from TAP controller.
+		.UPDATE (update),  // 1-bit output: UPDATE output from TAP controller
+		.TDO1   (tdo),     // 1-bit input: Test Data Output (TDO) input
+		                   //              for USER1 function.
+		.TDO2   ()         // 1-bit input: USER2 function
+	);
+`else
 `ifdef spartan6
 	BSCAN_SPARTAN6 #(
 `else
@@ -88,5 +116,6 @@ module spiOverJtag
 		.TDO     (tdo)     // 1-bit input: Test Data Output (TDO) input
 		                   //              for USER function.
 	);
+`endif
 
 endmodule