diff --git a/include/arm11/gpio.h b/include/arm11/gpio.h
new file mode 100644
index 0000000..ad88174
--- /dev/null
+++ b/include/arm11/gpio.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include "types.h"
+
+
+
+/**
+ * @brief      Sets a bit in the specified GPIO register.
+ *
+ * @param[in]  reg     The register number.
+ * @param[in]  bitNum  The bit number.
+ */
+void gpioSetBit(u16 reg, u8 bitNum);
+
+/**
+ * @brief      Clears a bit in the specified GPIO register.
+ *
+ * @param[in]  reg     The register number.
+ * @param[in]  bitNum  The bit number.
+ */
+void gpioClearBit(u16 reg, u8 bitNum);
diff --git a/include/arm11/interrupt.h b/include/arm11/interrupt.h
index 03817f9..407f396 100644
--- a/include/arm11/interrupt.h
+++ b/include/arm11/interrupt.h
@@ -21,7 +21,8 @@
 	IRQ_MPCORE_SW13 = 13,
 	IRQ_MPCORE_SW14 = 14,
 	IRQ_MPCORE_SW15 = 15,
-	IRQ_PXI_SYNC    = 80
+	IRQ_PXI_SYNC    = 80,
+	IRQ_MCU_HID     = 113
 } Interrupt;
 
 
diff --git a/source/arm11/gpio.c b/source/arm11/gpio.c
new file mode 100644
index 0000000..416712c
--- /dev/null
+++ b/source/arm11/gpio.c
@@ -0,0 +1,17 @@
+#include "types.h"
+#include "mem_map.h"
+
+
+#define REGs_GPIO   ((vu16*)(IO_MEM_ARM9_ARM11 + 0x47000))
+
+
+
+void gpioSetBit(u16 reg, u8 bitNum)
+{
+	REGs_GPIO[reg] |= 1u<<bitNum;
+}
+
+void gpioClearBit(u16 reg, u8 bitNum)
+{
+	REGs_GPIO[reg] &= ~(1u<<bitNum);
+}
diff --git a/source/arm11/gpio.s b/source/arm11/gpio.s
deleted file mode 100644
index 03d58cc..0000000
--- a/source/arm11/gpio.s
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "asmfunc.h"
-
-.arm
-.cpu mpcore
-.fpu vfpv2
-
-
-
-ASM_FUNC gpio_set_bit
-	ldrh r2, [r0]
-	movs r3, #1
-	movs r1, r3, lsl r1
-	orrs r2, r1
-	strh r2, [r0]
-	bx lr
-
-
-ASM_FUNC gpio_clear_bit
-	ldrh r2, [r0]
-	movs r3, #1
-	movs r1, r3, lsl r1
-	bics r2, r1
-	strh r2, [r0]
-	bx lr