diff --git a/arch/misoc/src/lm32/Make.defs b/arch/misoc/src/lm32/Make.defs
index 83381543884..cc4b72da664 100644
--- a/arch/misoc/src/lm32/Make.defs
+++ b/arch/misoc/src/lm32/Make.defs
@@ -42,8 +42,9 @@ CMN_CSRCS   = misoc_uart.c
 CHIP_ASRCS  = lm32_syscall.S
 
 CHIP_CSRCS  = lm32_allocateheap.c lm32_assert.c lm32_blocktask.c
-CHIP_CSRCS += lm32_copystate.c lm32_createstack.c lm32_doirq.c lm32_dumpstate.c
-CHIP_CSRCS += lm32_dumpstate.c lm32_exit.c lm32_idle.c lm32_initialize.c
-CHIP_CSRCS += lm32_initialstate.c lm32_interruptcontext.c lm32_irq.c
-CHIP_CSRCS += lm32_releasepending.c lm32_releasestack.c
-CHIP_CSRCS += lm32_stackframe.c lm32_swint.c lm32_unblocktask.c
+CHIP_CSRCS += lm32_copystate.c lm32_createstack.c lm32_decodeirq.c
+CHIP_CSRCS += lm32_doirq.c lm32_dumpstate.c lm32_dumpstate.c lm32_exit.c
+CHIP_CSRCS += lm32_idle.c lm32_initialize.c lm32_initialstate.c
+CHIP_CSRCS += lm32_interruptcontext.c lm32_irq.c lm32_releasepending.c
+CHIP_CSRCS += lm32_releasestack.c lm32_stackframe.c lm32_swint.c
+CHIP_CSRCS += lm32_unblocktask.c
diff --git a/arch/misoc/src/lm32/lm32_decodeirq.c b/arch/misoc/src/lm32/lm32_decodeirq.c
new file mode 100644
index 00000000000..a532331ca3b
--- /dev/null
+++ b/arch/misoc/src/lm32/lm32_decodeirq.c
@@ -0,0 +1,92 @@
+/********************************************************************************
+ * arch/misoc/src/lm32/lm32_decodeirq.c
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ********************************************************************************/
+
+/********************************************************************************
+ * Included Files
+ ********************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "chip.h"
+#include "lm32.h"
+
+/********************************************************************************
+ * Public Functions
+ ********************************************************************************/
+
+/****************************************************************************
+ * Name: lm32_decodeirq
+ *
+ * Description:
+ *   This function is called from the IRQ vector handler in lm32_vectors.S.
+ *   At this point, the interrupt has been taken and the registers have
+ *   been saved on the stack.  This function simply needs to determine the
+ *   the irq number of the interrupt and then to call lm32_doirq to dispatch
+ *   the interrupt.
+ *
+ *  Input parameters:
+ *   regs - A pointer to the register save area on the stack.
+ *
+ ****************************************************************************/
+
+uint32_t *lm32_decodeirq(uint32_t *regs)
+{
+  uint32_t im;
+  int irq;
+
+  /* Read the interrupt acknowledge register and get the interrupt ID */
+
+  im = getreg32(GIC_ICCIAR);
+  irq    = (im & GIC_ICCIAR_INTID_MASK) >> GIC_ICCIAR_INTID_SHIFT;
+
+  irqinfo("irq=%d\n", irq);
+
+  /* Ignore spurions IRQs.  ICCIAR will report 1023 if there is no pending
+   * interrupt.
+   */
+
+  DEBUGASSERT(irq < NR_IRQS || irq == 1023);
+  if (irq < NR_IRQS)
+    {
+      /* Dispatch the interrupt */
+
+      regs = lm32_doirq(irq, regs);
+    }
+
+  /* Write to the end-of-interrupt register */
+
+  putreg32(im, GIC_ICCEOIR);
+  return regs;
+}
diff --git a/arch/misoc/src/lm32/lm32_vectors.S b/arch/misoc/src/lm32/lm32_vectors.S
index 70187767dd4..f672fa7fda8 100644
--- a/arch/misoc/src/lm32/lm32_vectors.S
+++ b/arch/misoc/src/lm32/lm32_vectors.S
@@ -112,7 +112,7 @@ _interrupt_handler:
 	sw		(sp+0), ra
 	calli	.save_all
 	rcsr	r1, IP
-	calli	lm32_doirq
+	calli	lm32_decodeirq
 	bi		.restore_all_and_eret
 	nop
 	nop