diff --git a/converter/ps2_usb/config.h b/converter/ps2_usb/config.h
index 1ad2bd1b4..c9bab1b07 100644
--- a/converter/ps2_usb/config.h
+++ b/converter/ps2_usb/config.h
@@ -40,6 +40,52 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 )
 
 
+//#define NO_SUSPEND_POWER_DOWN
+
+
+/*
+ * PS/2 Busywait
+ */
+#ifdef PS2_USE_BUSYWAIT
+#define PS2_CLOCK_PORT  PORTD
+#define PS2_CLOCK_PIN   PIND
+#define PS2_CLOCK_DDR   DDRD
+#define PS2_CLOCK_BIT   5
+#define PS2_DATA_PORT   PORTD
+#define PS2_DATA_PIN    PIND
+#define PS2_DATA_DDR    DDRD
+#define PS2_DATA_BIT    2
+#endif
+
+/*
+ * PS/2 Pin interrupt
+ */
+#ifdef PS2_USE_INT
+/* uses INT1 for clock line(ATMega32U4) */
+#define PS2_CLOCK_PORT  PORTD
+#define PS2_CLOCK_PIN   PIND
+#define PS2_CLOCK_DDR   DDRD
+#define PS2_CLOCK_BIT   1
+#define PS2_DATA_PORT   PORTD
+#define PS2_DATA_PIN    PIND
+#define PS2_DATA_DDR    DDRD
+#define PS2_DATA_BIT    2
+#define PS2_INT_INIT()  do {    \
+    EICRA |= ((1<<ISC11) |      \
+              (0<<ISC10));      \
+} while (0)
+#define PS2_INT_ON()  do {      \
+    EIMSK |= (1<<INT1);         \
+} while (0)
+#define PS2_INT_OFF() do {      \
+    EIMSK &= ~(1<<INT1);        \
+} while (0)
+#define PS2_INT_VECT    INT1_vect
+#endif
+
+/*
+ * PS/2 USART
+ */
 #ifdef PS2_USE_USART
 #if defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)
 /* XCK for clock line and RXD for data line */
@@ -51,7 +97,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define PS2_DATA_PIN    PIND
 #define PS2_DATA_DDR    DDRD
 #define PS2_DATA_BIT    2
-
 /* synchronous, odd parity, 1-bit stop, 8-bit data, sample at falling edge */
 /* set DDR of CLOCK as input to be slave */
 #define PS2_USART_INIT() do {   \
@@ -82,7 +127,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define PS2_USART_RX_DATA       UDR1
 #define PS2_USART_ERROR         (UCSR1A & ((1<<FE1) | (1<<DOR1) | (1<<UPE1)))
 #define PS2_USART_RX_VECT       USART1_RX_vect
-
 #elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega168P__) || defined(__AVR_ATmega328P__)
 /* XCK for clock line and RXD for data line */
 #define PS2_CLOCK_PORT  PORTD
@@ -93,7 +137,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define PS2_DATA_PIN    PIND
 #define PS2_DATA_DDR    DDRD
 #define PS2_DATA_BIT    0
-
 /* synchronous, odd parity, 1-bit stop, 8-bit data, sample at falling edge */
 /* set DDR of CLOCK as input to be slave */
 #define PS2_USART_INIT() do {   \
@@ -127,41 +170,4 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 #endif
 
-
-#ifdef PS2_USE_INT
-/* uses INT1 for clock line(ATMega32U4) */
-#define PS2_CLOCK_PORT  PORTD
-#define PS2_CLOCK_PIN   PIND
-#define PS2_CLOCK_DDR   DDRD
-#define PS2_CLOCK_BIT   5
-#define PS2_DATA_PORT   PORTD
-#define PS2_DATA_PIN    PIND
-#define PS2_DATA_DDR    DDRD
-#define PS2_DATA_BIT    2
-
-#define PS2_INT_INIT()  do {    \
-    EICRA |= ((1<<ISC11) |      \
-              (0<<ISC10));      \
-} while (0)
-#define PS2_INT_ON()  do {      \
-    EIMSK |= (1<<INT1);         \
-} while (0)
-#define PS2_INT_OFF() do {      \
-    EIMSK &= ~(1<<INT1);        \
-} while (0)
-#define PS2_INT_VECT    INT1_vect
-#endif
-
-
-#ifdef PS2_USE_BUSYWAIT
-#define PS2_CLOCK_PORT  PORTD
-#define PS2_CLOCK_PIN   PIND
-#define PS2_CLOCK_DDR   DDRD
-#define PS2_CLOCK_BIT   5
-#define PS2_DATA_PORT   PORTD
-#define PS2_DATA_PIN    PIND
-#define PS2_DATA_DDR    DDRD
-#define PS2_DATA_BIT    2
-#endif
-
 #endif
diff --git a/converter/ps2_usb/matrix.c b/converter/ps2_usb/matrix.c
index aa0c38c68..45344c0f7 100644
--- a/converter/ps2_usb/matrix.c
+++ b/converter/ps2_usb/matrix.c
@@ -29,6 +29,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 static void matrix_make(uint8_t code);
 static void matrix_break(uint8_t code);
+static void matrix_clear(void);
 #ifdef MATRIX_HAS_GHOST
 static bool matrix_has_ghost_in_row(uint8_t row);
 #endif
@@ -84,6 +85,7 @@ uint8_t matrix_cols(void)
 
 void matrix_init(void)
 {
+    debug_enable = true;
     ps2_host_init();
 
     // initialize matrix state: all keys off
@@ -209,16 +211,18 @@ uint8_t matrix_scan(void)
                         state = INIT;
                         break;
                     case 0x00:  // Overrun [3]p.25
-                        print("Overrun\n");
+                        matrix_clear();
                         clear_keyboard();
+                        print("Overrun\n");
                         state = INIT;
                         break;
                     default:    // normal key make
                         if (code < 0x80) {
                             matrix_make(code);
                         } else {
-                            xprintf("unexpected scan code at INIT: %02X\n", code);
+                            matrix_clear();
                             clear_keyboard();
+                            xprintf("unexpected scan code at INIT: %02X\n", code);
                         }
                         state = INIT;
                 }
@@ -239,8 +243,9 @@ uint8_t matrix_scan(void)
                         if (code < 0x80) {
                             matrix_make(code|0x80);
                         } else {
-                            xprintf("unexpected scan code at E0: %02X\n", code);
+                            matrix_clear();
                             clear_keyboard();
+                            xprintf("unexpected scan code at E0: %02X\n", code);
                         }
                         state = INIT;
                 }
@@ -255,12 +260,18 @@ uint8_t matrix_scan(void)
                         matrix_break(PRINT_SCREEN);
                         state = INIT;
                         break;
+                    case 0xF0:
+                        matrix_clear();
+                        clear_keyboard();
+                        xprintf("unexpected scan code at F0: F0(clear and cont.)\n");
+                        break;
                     default:
                     if (code < 0x80) {
                         matrix_break(code);
                     } else {
-                        xprintf("unexpected scan code at F0: %02X\n", code);
+                        matrix_clear();
                         clear_keyboard();
+                        xprintf("unexpected scan code at F0: %02X\n", code);
                     }
                     state = INIT;
                 }
@@ -275,8 +286,9 @@ uint8_t matrix_scan(void)
                         if (code < 0x80) {
                             matrix_break(code|0x80);
                         } else {
-                            xprintf("unexpected scan code at E0_F0: %02X\n", code);
+                            matrix_clear();
                             clear_keyboard();
+                            xprintf("unexpected scan code at E0_F0: %02X\n", code);
                         }
                         state = INIT;
                 }
@@ -369,10 +381,13 @@ uint8_t matrix_scan(void)
         }
     }
 
-    if (ps2_error > PS2_ERR_STARTBIT3) {
+    // TODO: request RESEND when error occurs?
+/*
+    if (PS2_IS_FAILED(ps2_error)) {
         uint8_t ret = ps2_host_send(PS2_RESEND);
         xprintf("Resend: %02X\n", ret);
     }
+*/
     return 1;
 }
 
@@ -464,3 +479,9 @@ static void matrix_break(uint8_t code)
         is_modified = true;
     }
 }
+
+inline
+static void matrix_clear(void)
+{
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
+}