diff --git a/include/arch/aarch64/arch.h b/include/arch/aarch64/arch.h
index 81e0f27..92e6737 100644
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@@ -226,6 +226,12 @@
 #define ID_AA64MMFR0_EL1_TGRAN16_SUPPORTED	ULL(0x1)
 #define ID_AA64MMFR0_EL1_TGRAN16_NOT_SUPPORTED	ULL(0x0)
 
+/* ID_AA64MMFR1_EL1 definitions */
+#define ID_AA64MMFR1_EL1_TWED_SHIFT		U(32)
+#define ID_AA64MMFR1_EL1_TWED_MASK		ULL(0xf)
+#define ID_AA64MMFR1_EL1_TWED_SUPPORTED		ULL(0x1)
+#define ID_AA64MMFR1_EL1_TWED_NOT_SUPPORTED	ULL(0x0)
+
 /* ID_AA64MMFR2_EL1 definitions */
 #define ID_AA64MMFR2_EL1		S3_0_C0_C7_2
 
@@ -312,6 +318,9 @@
 
 /* SCR definitions */
 #define SCR_RES1_BITS		((U(1) << 4) | (U(1) << 5))
+#define SCR_TWEDEL_SHIFT	U(30)
+#define SCR_TWEDEL_MASK		ULL(0xf)
+#define SCR_TWEDEn_BIT		(UL(1) << 29)
 #define SCR_ATA_BIT		(U(1) << 26)
 #define SCR_FIEN_BIT		(U(1) << 21)
 #define SCR_EEL2_BIT		(U(1) << 18)
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 9513e97..49d827d 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -58,4 +58,10 @@
 		ID_AA64PFR0_SEL2_MASK) == 1ULL;
 }
 
+static inline bool is_armv8_6_twed_present(void)
+{
+	return (((read_id_aa64mmfr1_el1() >> ID_AA64MMFR1_EL1_TWED_SHIFT) &
+		ID_AA64MMFR1_EL1_TWED_MASK) == ID_AA64MMFR1_EL1_TWED_SUPPORTED);
+}
+
 #endif /* ARCH_FEATURES_H */
diff --git a/include/arch/aarch64/arch_helpers.h b/include/arch/aarch64/arch_helpers.h
index 9cd1ae5..09059ca 100644
--- a/include/arch/aarch64/arch_helpers.h
+++ b/include/arch/aarch64/arch_helpers.h
@@ -358,6 +358,7 @@
 DEFINE_SYSREG_READ_FUNC(midr_el1)
 DEFINE_SYSREG_READ_FUNC(mpidr_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64mmfr0_el1)
+DEFINE_SYSREG_READ_FUNC(id_aa64mmfr1_el1)
 
 DEFINE_SYSREG_RW_FUNCS(scr_el3)
 DEFINE_SYSREG_RW_FUNCS(hcr_el2)
diff --git a/include/lib/extensions/twed.h b/include/lib/extensions/twed.h
new file mode 100644
index 0000000..eac4aa3
--- /dev/null
+++ b/include/lib/extensions/twed.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef TWED_H
+#define TWED_H
+
+#include <stdint.h>
+
+#define TWED_DISABLED U(0xFFFFFFFF)
+
+uint32_t plat_arm_set_twedel_scr_el3(void);
+
+#endif /* TWEDE_H */