diff --git a/rtl/sys_gen/README.md b/rtl/sys_gen/README.md
index 53e4780d..e158444c 100644
--- a/rtl/sys_gen/README.md
+++ b/rtl/sys_gen/README.md
@@ -1,12 +1,12 @@
 This directory sub-tree contains **HDL sources for top level designs** 
 and is organized in
 
-| Directory | Content |
-| --------- | ------- |
-| [tst_mig](tst_mig)               | MIG core tester |
-| [tst_rlink](tst_rlink)           | rlink tester (over serial links) |
-| [tst_rlink_cuff](tst_rlink_cuff) | rlink tester (over Cypress FX2 USB) |
-| [tst_serloop](tst_serloop)       | serial port loop back tester |
-| [tst_snhumanio](tst_snhumanio)   | Digilent board human IO tester |
-| [tst_sram](tst_sram)             | memory tester (SRAM or CRAM) |
-| [w11a](w11a)                     | w11a systems |
+| Directory                        | Content                             | s3 | n2 | n3 |atl| n4 | n4d| arty| as7| b3 | c7 |
+| -------------------------------- | -------------------------------- |:--:|:--:|:--:|:-:|:--:|:--:|:---:|:--:|:--:|:--:|
+| [tst_mig](tst_mig)               | MIG core tester                  |  - |  - |  - | - |  - |  y |   y |  - |  - |  - |
+| [tst_rlink](tst_rlink)           | rlink tester (over serial links) |  y |  y |  y | - |  y |  y |   y |  - |  y |  y |
+| [tst_rlink_cuff](tst_rlink_cuff) | rlink tester (over Cypress FX2)  |  - |  y |  y | y |  - |  - |   - |  - |  - |  - |
+| [tst_serloop](tst_serloop)       | serial port loop back tester     |  y |  y |  y | - |  y |  y |   - |  - |  - |  - |
+| [tst_snhumanio](tst_snhumanio)   | Digilent board human IO tester   |  y |  y |  y | y |  y |  y |   - |  - |  y |  - |
+| [tst_sram](tst_sram)             | memory tester                    |  y |  y |  y | - |  y |  y |   y |  - |  - |  y |
+| [w11a](w11a)                     | w11a systems                     |  y |  y |  y | - |  y |  y |   y |  y |  y |  y |
diff --git a/rtl/sys_gen/tst_mig/README.md b/rtl/sys_gen/tst_mig/README.md
new file mode 100644
index 00000000..f4f4d5fa
--- /dev/null
+++ b/rtl/sys_gen/tst_mig/README.md
@@ -0,0 +1,7 @@
+This directory sub-tree contains **MIG core tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [arty](arty)       | design for Digilent Arty A7-35 |
+| [nexys4d](nexys4d) | design for Digilent Nexys4 DDR  _!! only sim-tested !!_ |
diff --git a/rtl/sys_gen/tst_rlink/README.md b/rtl/sys_gen/tst_rlink/README.md
new file mode 100644
index 00000000..7eca259b
--- /dev/null
+++ b/rtl/sys_gen/tst_rlink/README.md
@@ -0,0 +1,13 @@
+This directory sub-tree contains **rlink over serial link tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [arty](arty)       | design for Digilent Arty A7-35 |
+| [basys3](basys3)   | design for Digilent Basys3 |
+| [cmoda7](cmoda7)   | design for Digilent Cmod A7 (35 die size) |
+| [nexys2](nexys2)   | design for Digilent Nexys2 |
+| [nexys3](nexys3)   | design for Digilent Nexys3 |
+| [nexys4](nexys4)   | design for Digilent Nexys4 (old CRAM version) |
+| [nexys4d](nexys4d) | design for Digilent Nexys4 DDR _!! only sim-tested !!_ |
+| [s3board](s3board) | design for Digilent S3BOARD |
diff --git a/rtl/sys_gen/tst_rlink_cuff/README.md b/rtl/sys_gen/tst_rlink_cuff/README.md
new file mode 100644
index 00000000..8e5a93de
--- /dev/null
+++ b/rtl/sys_gen/tst_rlink_cuff/README.md
@@ -0,0 +1,8 @@
+This directory sub-tree contains **rlink over Cypress FX2 tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [atlys](atlys)     | design for Digilent Atlys |
+| [nexys2](nexys2)   | design for Digilent Nexys2 |
+| [nexys3](nexys3)   | design for Digilent Nexys3 |
diff --git a/rtl/sys_gen/tst_serloop/README.md b/rtl/sys_gen/tst_serloop/README.md
new file mode 100644
index 00000000..1fa2d8f7
--- /dev/null
+++ b/rtl/sys_gen/tst_serloop/README.md
@@ -0,0 +1,10 @@
+This directory sub-tree contains **serial port loop back tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [nexys2](nexys2)   | design for Digilent Nexys2 |
+| [nexys3](nexys3)   | design for Digilent Nexys3 |
+| [nexys4](nexys4)   | design for Digilent Nexys4 (old CRAM version) |
+| [nexys4d](nexys4d) | design for Digilent Nexys4 DDR _!! only sim-tested !!_ |
+| [s3board](s3board) | design for Digilent S3BOARD |
diff --git a/rtl/sys_gen/tst_snhumanio/README.md b/rtl/sys_gen/tst_snhumanio/README.md
new file mode 100644
index 00000000..9a26c41e
--- /dev/null
+++ b/rtl/sys_gen/tst_snhumanio/README.md
@@ -0,0 +1,12 @@
+This directory sub-tree contains **Digilent board human IO tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [atlys](atlys)     | design for Digilent Atlys |
+| [basys3](basys3)   | design for Digilent Basys3 |
+| [nexys2](nexys2)   | design for Digilent Nexys2 |
+| [nexys3](nexys3)   | design for Digilent Nexys3 |
+| [nexys4](nexys4)   | design for Digilent Nexys4 (old CRAM version) |
+| [nexys4d](nexys4d) | design for Digilent Nexys4 DDR _!! only sim-tested !!_ |
+| [s3board](s3board) | design for Digilent S3BOARD |
diff --git a/rtl/sys_gen/tst_sram/README.md b/rtl/sys_gen/tst_sram/README.md
new file mode 100644
index 00000000..7a0b4d64
--- /dev/null
+++ b/rtl/sys_gen/tst_sram/README.md
@@ -0,0 +1,12 @@
+This directory sub-tree contains **memory tester systems** 
+and is organized in
+
+| Directory | Content |
+| --------- | ------- |
+| [arty](arty)       | design for Digilent Arty A7-35 |
+| [cmoda7](cmoda7)   | design for Digilent Cmod A7 (35 die size) |
+| [nexys2](nexys2)   | design for Digilent Nexys2 |
+| [nexys3](nexys3)   | design for Digilent Nexys3 |
+| [nexys4](nexys4)   | design for Digilent Nexys4 (old CRAM version) |
+| [nexys4d](nexys4d) | design for Digilent Nexys4 DDR _!! only sim-tested !!_ |
+| [s3board](s3board) | design for Digilent S3BOARD |