diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_api.c
index c338d84275..81d4be52cb 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_api.c
@@ -71,13 +71,15 @@ void gpio_init(gpio_t *obj, PinName pin)
 {
     obj->pin = pin;
 
-    if (pin == (PinName)NC)
+    if (pin == (PinName)NC) {
         return;
+    }
 
     // Initialize the GPIO driver. This function
     // initializes the GPIO driver only once globally.
-    if (!gpio_initialized)
+    if (!gpio_initialized) {
         adi_gpio_Init(gpioMemory, ADI_GPIO_MEMORY_SIZE);
+    }
 
     pin_function(pin, MUX_FUNC_0);
 }
@@ -134,11 +136,12 @@ int gpio_read(gpio_t *obj)
     uint16_t Data;
 
     // check whether the pin is configured as input or output
-    if ((gpio_oen[port] >> pin_num) & 1)
+    if ((gpio_oen[port] >> pin_num) & 1) {
         Data = gpio_output_val[port] & (1 << pin_num);
-    else
+    } else {
         // otherwise call GetData
         adi_gpio_GetData((ADI_GPIO_PORT)port, (1 << pin_num), &Data);
+    }
 
     return ((((uint32_t)Data) >> pin_num) & 1);
 }
diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_irq_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_irq_api.c
index ae5b8234c3..3cf237218b 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_irq_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/gpio_irq_api.c
@@ -183,8 +183,9 @@ int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32
     uint32_t pin_num = pin & 0xFF;
 
     // check for valid pin and ID
-    if ((pin == NC) || (id == 0))
+    if ((pin == NC) || (id == 0)) {
         return -1;
+    }
 
     // make sure gpio driver has been initialized
     if (!gpio_initialized) {
@@ -193,8 +194,9 @@ int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32
     }
 
     // save the handler
-    if (handler)
+    if (handler) {
         irq_handler = handler;
+    }
 
     // disable the interrupt for the given pin
     disable_pin_interrupt((ADI_GPIO_PORT)port, pin_num);
@@ -242,16 +244,18 @@ void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
     uint32_t port = obj->pinname >> GPIO_PORT_SHIFT;
     uint32_t pin_num = obj->pinname & 0xFF;
 
-    if (event == IRQ_NONE)
+    if (event == IRQ_NONE) {
         return;
+    }
 
     // read the current polarity register
     adi_gpio_GetGroupInterruptPolarity((ADI_GPIO_PORT)port,	1 << pin_num, &int_polarity_reg);
 
-    if (event == IRQ_RISE)
+    if (event == IRQ_RISE) {
         int_polarity_reg |= (1 << pin_num);
-    else
+    } else {
         int_polarity_reg &= ~(1 << pin_num);
+    }
 
     // set the polarity register
     adi_gpio_SetGroupInterruptPolarity((ADI_GPIO_PORT)port, int_polarity_reg);
@@ -259,10 +263,11 @@ void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
     channel_ids[port][pin_num].event = event;
 
     // enable interrupt for this pin if enable flag is set
-    if (enable)
+    if (enable) {
         gpio_irq_enable(obj);
-    else
+    } else {
         gpio_irq_disable(obj);
+    }
 }
 
 /** Enable GPIO IRQ
@@ -275,8 +280,9 @@ void gpio_irq_enable(gpio_irq_t *obj)
     uint32_t port = obj->pinname >> GPIO_PORT_SHIFT;
     uint32_t pin_num = obj->pinname & 0xFF;
 
-    if (channel_ids[port][pin_num].event == IRQ_NONE)
+    if (channel_ids[port][pin_num].event == IRQ_NONE) {
         return;
+    }
 
     // Group all RISE interrupts in INTA and FALL interrupts in INTB
     if (channel_ids[port][pin_num].event == IRQ_RISE) {
@@ -302,14 +308,17 @@ void gpio_irq_disable(gpio_irq_t *obj)
     uint32_t port = obj->pinname >> GPIO_PORT_SHIFT;
     uint32_t pin_num = obj->pinname & 0xFF;
 
-    if (channel_ids[port][pin_num].event == IRQ_NONE)
+    if (channel_ids[port][pin_num].event == IRQ_NONE) {
         return;
+    }
 
     // Group all RISE interrupts in INTA and FALL interrupts in INTB
-    if (channel_ids[port][pin_num].event == IRQ_RISE)
+    if (channel_ids[port][pin_num].event == IRQ_RISE) {
         disable_pin_interrupt((ADI_GPIO_PORT)port, pin_num);
-    else if (channel_ids[port][pin_num].event == IRQ_FALL)
+    }
+    else if (channel_ids[port][pin_num].event == IRQ_FALL) {
         disable_pin_interrupt((ADI_GPIO_PORT)port, pin_num);
+    }
 
     channel_ids[port][pin_num].int_enable = 0;
 }
diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/i2c_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/i2c_api.c
index afa0312f47..f25d80c910 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/i2c_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/i2c_api.c
@@ -110,13 +110,15 @@ void i2c_init(i2c_t *obj, PinName sda, PinName scl)
 
 int i2c_start(i2c_t *obj)
 {
-    return 0;
+    /* The Hardware does not support this feature. */
+    return -1;
 }
 
 
 int i2c_stop(i2c_t *obj)
 {
-    return 0;
+    /* The Hardware does not support this feature. */
+    return -1;
 }
 
 
@@ -204,13 +206,15 @@ void i2c_reset(i2c_t *obj)
 
 int i2c_byte_read(i2c_t *obj, int last)
 {
-    return 0;
+    /* The Hardware does not support this feature. */
+    return -1;
 }
 
 
 int i2c_byte_write(i2c_t *obj, int data)
 {
-    return 0;
+    /* The Hardware does not support this feature. */
+    return -1;
 }
 
 #endif  // #if DEVICE_I2C
diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/serial_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/serial_api.c
index 0a118c0cca..c6af733fad 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/serial_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/serial_api.c
@@ -53,16 +53,16 @@
 #include "PeripheralPins.h"
 #include "drivers/uart/adi_uart.h"
 #define ADI_UART_MEMORY_SIZE   (ADI_UART_BIDIR_MEMORY_SIZE)
-#define ADI_UART_NUM_DEVICES 2
+#define ADI_UART_NUM_DEVICES   2
 
-static ADI_UART_HANDLE          hDevice[ADI_UART_NUM_DEVICES];
+static ADI_UART_HANDLE hDevice[ADI_UART_NUM_DEVICES];
 static uint32_t UartDeviceMem[ADI_UART_NUM_DEVICES][(ADI_UART_MEMORY_SIZE + 3)/4];
 static uint32_t serial_irq_ids[ADI_UART_NUM_DEVICES] = {0};
 static uart_irq_handler irq_handler = NULL;
 int stdio_uart_inited = 0;
 serial_t stdio_uart;
-int rxbuffer[2];
-int txbuffer[2];
+static int rxbuffer[2];
+static int txbuffer[2];
 
 static void uart_callback(void *pCBParam, uint32_t Event, void *pArg)
 {
diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/spi_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/spi_api.c
index b788e5b2ad..76015a4b2d 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/spi_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/spi_api.c
@@ -305,7 +305,28 @@ int spi_master_write(spi_t *obj, int value)
  */
 int spi_master_block_write(spi_t *obj, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, char write_fill)
 {
-    return 0;
+    ADI_SPI_TRANSCEIVER transceive;
+    ADI_SPI_HANDLE  SPI_Handle;
+    ADI_SPI_RESULT  SPI_Return = ADI_SPI_SUCCESS;
+
+    transceive.pReceiver        = rx_buffer;
+    transceive.ReceiverBytes    = rx_length;    /* link transceive data size to the remaining count */
+    transceive.nRxIncrement     = 1;            /* auto increment buffer */
+    transceive.pTransmitter     = tx_buffer;    /* initialize data attributes */
+    transceive.TransmitterBytes = tx_length;    /* link transceive data size to the remaining count */
+    transceive.nTxIncrement     = 1;            /* auto increment buffer */
+
+    transceive.bDMA = false;
+    transceive.bRD_CTL = false;
+    SPI_Handle = *obj->pSPI_Handle;
+    SPI_Return = adi_spi_MasterReadWrite(SPI_Handle, &transceive);
+    if (SPI_Return) {
+        obj->error = SPI_EVENT_ERROR;
+        return -1;
+    }
+    else {
+        return((int)tx_length);
+    }
 }
 
 #endif
diff --git a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/trng_api.c b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/trng_api.c
index 8106f44e59..de9d710697 100755
--- a/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/trng_api.c
+++ b/targets/TARGET_Analog_Devices/TARGET_ADUCM4X50/TARGET_ADUCM4050/api/trng_api.c
@@ -88,18 +88,28 @@ int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_l
     ADI_RNG_HANDLE RNGhDevice = obj->RNGhDevice;
     bool bRNGRdy;
     uint32_t nRandomNum, i;
+    ADI_RNG_RESULT result;
 
     for (i = 0; i < length; i++) {
         // Loop until the device has data to be read
         do {
-            adi_rng_GetRdyStatus(RNGhDevice, &bRNGRdy);
+            result = adi_rng_GetRdyStatus(RNGhDevice, &bRNGRdy);
+            if (result != ADI_RNG_SUCCESS)
+            {
+                return -1;
+            }
         } while (!bRNGRdy);
 
         // Read the RNG
-        adi_rng_GetRngData(RNGhDevice, &nRandomNum);
+        result = adi_rng_GetRngData(RNGhDevice, &nRandomNum);
+
+        if (result != ADI_RNG_SUCCESS)
+        {
+            return -1;
+        }
 
         // Save the output
-		output[i] = (uint8_t)nRandomNum;
+		output[i] = (uint8_t)(nRandomNum & 0xFF);
     }
 
     *output_length = length;