diff --git a/stm32-data-gen/src/rcc.rs b/stm32-data-gen/src/rcc.rs
index 0b00339..b0b00f6 100644
--- a/stm32-data-gen/src/rcc.rs
+++ b/stm32-data-gen/src/rcc.rs
@@ -6,7 +6,7 @@ use std::hash::Hash;
 use anyhow::{anyhow, Ok};
 use chiptool::ir::{BlockItemInner, Enum};
 use stm32_data_serde::chip::core::peripheral;
-use stm32_data_serde::chip::core::peripheral::rcc::Mux;
+use stm32_data_serde::chip::core::peripheral::rcc::{Mux, StopMode};
 
 use crate::regex;
 use crate::registers::Registers;
@@ -245,6 +245,13 @@ impl PeripheralToClock {
                         for field in &body.fields {
                             if let Some(peri) = field.name.strip_suffix("EN") {
                                 let peri = if peri == "RTCAPB" { "RTC" } else { peri };
+                                let stop_mode = if peri == "RTC" {
+                                    StopMode::Standby
+                                } else if peri.starts_with("LP") {
+                                    StopMode::Stop2
+                                } else {
+                                    StopMode::Stop1
+                                };
 
                                 // Timers are a bit special, they may have a x2 freq
                                 let peri_clock = {
@@ -280,6 +287,7 @@ impl PeripheralToClock {
                                                 register: reg.to_ascii_lowercase(),
                                                 field: field.name.to_ascii_lowercase(),
                                             },
+                                            stop_mode,
                                             reset,
                                             mux,
                                         });
diff --git a/stm32-data-serde/src/lib.rs b/stm32-data-serde/src/lib.rs
index ba07b9c..c82633c 100644
--- a/stm32-data-serde/src/lib.rs
+++ b/stm32-data-serde/src/lib.rs
@@ -10,6 +10,10 @@ macro_rules! regex {
     }};
 }
 
+fn is_default<T: Default + PartialEq>(variant: &T) -> bool {
+    *variant == T::default()
+}
+
 #[derive(Clone, Debug, Eq, PartialEq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
 pub struct Chip {
     pub name: String,
@@ -116,6 +120,8 @@ pub mod chip {
                 pub reset: Option<rcc::Reset>,
                 #[serde(skip_serializing_if = "Option::is_none")]
                 pub mux: Option<rcc::Mux>,
+                #[serde(default, skip_serializing_if = "crate::is_default")]
+                pub stop_mode: rcc::StopMode,
             }
 
             pub mod rcc {
@@ -138,6 +144,14 @@ pub mod chip {
                     pub register: String,
                     pub field: String,
                 }
+
+                #[derive(Clone, Debug, Eq, PartialEq, Hash, PartialOrd, Ord, Serialize, Deserialize, Default)]
+                pub enum StopMode {
+                    #[default]
+                    Stop1, // Peripheral prevents chip from entering Stop1
+                    Stop2,   // Peripheral prevents chip from entering Stop2
+                    Standby, // Peripheral does not prevent chip from entering Stop
+                }
             }
 
             #[derive(Clone, Debug, Eq, PartialEq, Hash, Serialize, Deserialize)]
diff --git a/stm32-metapac-gen/res/src/metadata.rs b/stm32-metapac-gen/res/src/metadata.rs
index e468451..a1e028a 100644
--- a/stm32-metapac-gen/res/src/metadata.rs
+++ b/stm32-metapac-gen/res/src/metadata.rs
@@ -182,6 +182,7 @@ pub struct PeripheralRcc {
     pub enable: Option<PeripheralRccRegister>,
     pub reset: Option<PeripheralRccRegister>,
     pub mux: Option<PeripheralRccRegister>,
+    pub stop_mode: StopMode,
 }
 
 #[derive(Debug, Eq, PartialEq, Clone)]
@@ -190,6 +191,14 @@ pub struct PeripheralRccRegister {
     pub field: &'static str,
 }
 
+#[derive(Debug, Eq, PartialEq, Clone, Default)]
+pub enum StopMode {
+    #[default]
+    Stop1, // Peripheral prevents chip from entering Stop1
+    Stop2,   // Peripheral prevents chip from entering Stop2
+    Standby, // Peripheral does not prevent chip from entering Stop
+}
+
 #[derive(Debug, Eq, PartialEq, Clone)]
 pub struct PeripheralPin {
     pub pin: &'static str,
diff --git a/stm32-metapac-gen/src/data.rs b/stm32-metapac-gen/src/data.rs
index c7363f1..b85f3cf 100644
--- a/stm32-metapac-gen/src/data.rs
+++ b/stm32-metapac-gen/src/data.rs
@@ -325,6 +325,8 @@ pub struct PeripheralRcc {
     pub reset: Option<PeripheralRccRegister>,
     #[serde(default)]
     pub mux: Option<PeripheralRccRegister>,
+    #[serde(default)]
+    pub stop_mode: StopMode,
 }
 
 #[derive(Debug, Eq, PartialEq, Clone, Deserialize)]
@@ -333,6 +335,14 @@ pub struct PeripheralRccRegister {
     pub field: String,
 }
 
+#[derive(EnumDebug, Eq, PartialEq, Clone, Deserialize, Default)]
+pub enum StopMode {
+    #[default]
+    Stop1, // Peripheral prevents chip from entering Stop1
+    Stop2,   // Peripheral prevents chip from entering Stop2
+    Standby, // Peripheral does not prevent chip from entering Stop
+}
+
 #[derive(Debug, Eq, PartialEq, Clone, Deserialize)]
 pub struct PeripheralPin {
     pub pin: String,