diff --git a/minitests/eccbits/.gitignore b/minitests/eccbits/.gitignore
new file mode 100644
index 00000000..bc8f2f32
--- /dev/null
+++ b/minitests/eccbits/.gitignore
@@ -0,0 +1,7 @@
+/.Xil
+/design/
+/design.bit
+/design.bits
+/design.dcp
+/usage_statistics_webtalk.*
+/vivado*
diff --git a/minitests/eccbits/runme.sh b/minitests/eccbits/runme.sh
new file mode 100755
index 00000000..d5883a92
--- /dev/null
+++ b/minitests/eccbits/runme.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -ex
+vivado -mode batch -source runme.tcl
+${XRAY_BITREAD} -F $XRAY_ROI_FRAMES -z -y -C -o design.bits design.bit
+grep -h _050_ design.bits | cut -f4 -d_ | sort | uniq -c
diff --git a/minitests/eccbits/runme.tcl b/minitests/eccbits/runme.tcl
new file mode 100644
index 00000000..263a3314
--- /dev/null
+++ b/minitests/eccbits/runme.tcl
@@ -0,0 +1,50 @@
+create_project -force -part $::env(XRAY_PART) design design
+
+read_verilog top.v
+synth_design -top top
+
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_00) IOSTANDARD LVCMOS33" [get_ports a]
+set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_01) IOSTANDARD LVCMOS33" [get_ports y]
+
+create_pblock roi
+resize_pblock [get_pblocks roi] -add "$::env(XRAY_ROI)"
+
+set_property CFGBVS VCCO [current_design]
+set_property CONFIG_VOLTAGE 3.3 [current_design]
+set_property BITSTREAM.GENERAL.PERFRAMECRC YES [current_design]
+
+source ../../utils/utils.tcl
+
+proc get_rand_lut6_init {} {
+	return "64'h[format %08x [expr int(rand() * 65536 * 65536)]][format %08x [expr int(rand() * 65536 * 65536)]]"
+}
+
+set i 1
+foreach site [randsample_list 100 [get_sites -of_objects [get_pblocks roi]]] {
+	puts "$i/100: $site"
+	incr i
+
+	create_cell -reference LUT6 LUT_${site}_ALUT
+	create_cell -reference LUT6 LUT_${site}_BLUT
+	create_cell -reference LUT6 LUT_${site}_CLUT
+	create_cell -reference LUT6 LUT_${site}_DLUT
+
+	set_property -dict "LOC $site BEL A6LUT INIT [get_rand_lut6_init]" [get_cells LUT_${site}_ALUT]
+	set_property -dict "LOC $site BEL B6LUT INIT [get_rand_lut6_init]" [get_cells LUT_${site}_BLUT]
+	set_property -dict "LOC $site BEL C6LUT INIT [get_rand_lut6_init]" [get_cells LUT_${site}_CLUT]
+	set_property -dict "LOC $site BEL D6LUT INIT [get_rand_lut6_init]" [get_cells LUT_${site}_DLUT]
+
+	connect_net -net [get_nets y_OBUF] -objects [get_pins "
+		LUT_${site}_ALUT/I0 LUT_${site}_ALUT/I1 LUT_${site}_ALUT/I2 LUT_${site}_ALUT/I3 LUT_${site}_ALUT/I4 LUT_${site}_ALUT/I5
+		LUT_${site}_BLUT/I0 LUT_${site}_BLUT/I1 LUT_${site}_BLUT/I2 LUT_${site}_BLUT/I3 LUT_${site}_BLUT/I4 LUT_${site}_BLUT/I5
+		LUT_${site}_CLUT/I0 LUT_${site}_CLUT/I1 LUT_${site}_CLUT/I2 LUT_${site}_CLUT/I3 LUT_${site}_CLUT/I4 LUT_${site}_CLUT/I5
+		LUT_${site}_DLUT/I0 LUT_${site}_DLUT/I1 LUT_${site}_DLUT/I2 LUT_${site}_DLUT/I3 LUT_${site}_DLUT/I4 LUT_${site}_DLUT/I5
+	"]
+}
+
+place_design
+route_design
+
+write_checkpoint -force design.dcp
+write_bitstream -force design.bit
+
diff --git a/minitests/eccbits/top.v b/minitests/eccbits/top.v
new file mode 100644
index 00000000..88e41bd6
--- /dev/null
+++ b/minitests/eccbits/top.v
@@ -0,0 +1,3 @@
+module top (input a, output y);
+	assign y = a;
+endmodule