diff --git a/plat/arm/board/n1sdp/include/platform_def.h b/plat/arm/board/n1sdp/include/platform_def.h
index b3799a7..74d0c91 100644
--- a/plat/arm/board/n1sdp/include/platform_def.h
+++ b/plat/arm/board/n1sdp/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -190,11 +190,47 @@
 #define PLAT_CSS_MHU_BASE			0x45000000
 #define PLAT_MAX_PWR_LVL			2
 
-#define PLAT_ARM_G1S_IRQS			ARM_G1S_IRQS,			\
-						CSS_IRQ_MHU
-#define PLAT_ARM_G0_IRQS			ARM_G0_IRQS
+/* Interrupt handling constants */
+#define N1SDP_IRQ_MMU_TCU1_EVENT_Q_SEC		U(257)
+#define N1SDP_IRQ_MMU_TCU1_CMD_SYNC_SEC		U(258)
+#define N1SDP_IRQ_MMU_TCU1_GLOBAL		U(259)
+#define N1SDP_IRQ_MMU_TCU2_EVENT_Q_SEC		U(264)
+#define N1SDP_IRQ_MMU_TCU2_CMD_SYNC_SEC		U(265)
+#define N1SDP_IRQ_MMU_TCU2_GLOBAL		U(266)
+#define N1SDP_IRQ_CLUSTER0_MHU			U(349)
+#define N1SDP_IRQ_CLUSTER1_MHU			U(351)
+#define N1SDP_IRQ_P0_REFCLK			U(412)
+#define N1SDP_IRQ_P1_REFCLK			U(413)
+
+#define PLAT_ARM_G1S_IRQ_PROPS(grp) \
+	ARM_G1S_IRQ_PROPS(grp), \
+	INTR_PROP_DESC(CSS_IRQ_MHU, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(CSS_IRQ_TZ_WDOG, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(CSS_IRQ_SEC_SYS_TIMER, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU1_EVENT_Q_SEC, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU1_CMD_SYNC_SEC, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU1_GLOBAL, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU2_EVENT_Q_SEC, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU2_CMD_SYNC_SEC, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_MMU_TCU2_GLOBAL, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_CLUSTER0_MHU, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_CLUSTER1_MHU, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_P0_REFCLK, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL), \
+	INTR_PROP_DESC(N1SDP_IRQ_P1_REFCLK, \
+			GIC_HIGHEST_SEC_PRIORITY, grp, GIC_INTR_CFG_LEVEL)
 
-#define PLAT_ARM_G1S_IRQ_PROPS(grp)		CSS_G1S_IRQ_PROPS(grp)
 #define PLAT_ARM_G0_IRQ_PROPS(grp)		ARM_G0_IRQ_PROPS(grp)