diff --git a/README.md b/README.md
index 5580aa5..e8a15db 100644
--- a/README.md
+++ b/README.md
@@ -279,5 +279,6 @@ You can install the IP either by cloning this repository or by using [IPM](https
 |tx_level_below|output|1|TX FIFO level is below trhe threshold.|
 |tx_level|output|FAW|TX FIFO data level.|
 |ss|input|1|None|
+|enable|input|1|enable for spi master pulse generation|
 |done|output|1|spi done flag.|
 |busy|output|1|spi busy flag.|