diff --git a/data/registers/flash_f4.yaml b/data/registers/flash_f4.yaml
index 47a6f03..9836d6e 100644
--- a/data/registers/flash_f4.yaml
+++ b/data/registers/flash_f4.yaml
@@ -74,7 +74,7 @@ fieldset/CR:
     - name: SNB
       description: Sector number
       bit_offset: 3
-      bit_size: 4
+      bit_size: 5
     - name: PSIZE
       description: Program size
       bit_offset: 8
@@ -138,6 +138,14 @@ fieldset/OPTCR:
       description: Not write protect
       bit_offset: 16
       bit_size: 12
+    - name: DB1M
+      description: Dual-bank enable on 1 Mbyte Flash memory devices
+      bit_offset: 30
+      bit_size: 1
+    - name: SPRMOD
+      description: Selection of protection mode for nWPRi bits
+      bit_offset: 31
+      bit_size: 1
 fieldset/OPTKEYR:
   description: Flash option key register
   fields: