diff --git a/libraries/base/diag/diag.peripheral.yaml b/libraries/base/diag/diag.peripheral.yaml
index ac86812ef1440c831599e5e484f71145a97cec63..231834d3355ba9b3092ce4e4488fd3d80a12ed77 100644
--- a/libraries/base/diag/diag.peripheral.yaml
+++ b/libraries/base/diag/diag.peripheral.yaml
@@ -17,6 +17,7 @@ peripherals:
         mm_port_type: REG
         mm_port_description: "Waveform control."
         number_of_mm_ports: g_nof_streams
+        mm_port_span: 16
         fields:
           - - field_name: nof_samples
               field_description: "Number of samples in WG period."