diff --git a/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio.c b/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio.c
index 3051468..4be6a97 100644
--- a/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio.c
+++ b/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio.c
@@ -185,12 +185,13 @@ static int sdio_send_csd_cmd9(uint16_t rca, uint32_t *response_buffer) {
  * @param blklen Log2 of block length (9 in case of 512 byte block)
  * @param buff Buffer to send
  */
-static void sdio_write_buffer(uint32_t dlen, uint32_t log_blklen, const unsigned char *buff)
+static int sdio_write_buffer(uint32_t dlen, uint32_t log_blklen, const unsigned char *buff)
 {
 	uint32_t count;
 	int byte_count;
 	int byte_max;
 	uint32_t fifo;
+	uint32_t status_reg;
 
 	SDIO->DLEN = dlen;
 
@@ -213,6 +214,8 @@ static void sdio_write_buffer(uint32_t dlen, uint32_t log_blklen, const unsigned
 			fifo |= (((uint32_t)*(buff++)) << 24) & 0xFF000000;
 		}
 
+
+
 		/* Wait as long as FIFO is full */
 		while (SDIO->STA & SDIO_STA_TXFIFOF);
 
@@ -222,6 +225,14 @@ static void sdio_write_buffer(uint32_t dlen, uint32_t log_blklen, const unsigned
 
 	/* Wait for TX to complete */
 	while (SDIO->STA & SDIO_STA_TXACT);
+
+	status_reg = SDIO->STA;
+	if (status_reg & (SDIO_STA_DTIMEOUT | SDIO_STA_TXUNDERR | SDIO_STA_DCRCFAIL)) {
+		SDIO->DCTRL = 0UL;
+		return -1;
+	}
+
+	return 0;
 }
 
 static int sdio_send_write_block_cmd24(uint32_t addr)
@@ -779,17 +790,11 @@ DRESULT sdio_disk_write(const BYTE *buff, DWORD sector, UINT count)
 	if (ret)
 		return RES_ERROR;
 
-	while (count) {
-
-		sdio_write_buffer(512, 9, &buff[buff_offset]);
-
-		buff_offset += 512;
-		addr += (card_info.type == SD_V2_HC ? 1 : 512);
-		count--;
-	}
+	ret = 0;
+	ret = sdio_write_buffer((count * 512UL), 9, &buff[buff_offset]);
 
 	if (count_backup > 1)
 		(void)sdio_send_stop_transmission_cmd12();
 
-	return RES_OK;
+	return (ret ? RES_ERROR : RES_OK);
 }
diff --git a/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio_config.h b/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio_config.h
index 9e81c6d..e6b40d7 100644
--- a/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio_config.h
+++ b/stm-firmware/fatfs/shimatta_sdio_driver/shimatta_sdio_config.h
@@ -3,6 +3,8 @@
 
 #include <stm32/stm32f4xx.h>
 
+#define SDIO_CLOCK_FREQ 42000000UL
+
 //General Definitions
 //Blocksize: 512 = 2^9 => 9
 #define BLOCKSIZE 9     //9
@@ -12,11 +14,14 @@
 //4 bit: 4
 #define BUSWIDTH  4    //4
 //Initial Transfer CLK (ca. 400kHz)
-#define INITCLK   140   //120
+#define INITCLK   140UL   //120
 //Working CLK (Maximum)
-#define WORKCLK   8   //0
+#define WORKCLK   30UL   //0
 //Data Timeout in CLK Cycles
-#define DTIMEOUT  0x6000   //150
+
+#define DATA_TIMEOUT_MS 250UL // 250
+
+#define DTIMEOUT  (((SDIO_CLOCK_FREQ / (WORKCLK+2))) * DATA_TIMEOUT_MS / 1000UL)
 //DMA Stream used for TX and RX DMA2 Stream 3 or 6 possible
 // Currently not used due to possible misalignment of the data buffer.
 //#define DMASTREAM DMA2_Stream6