diff --git a/Core/Inc/stm32_si5351.h b/Core/Inc/stm32_si5351.h
index ca78632..81a9a80 100644
--- a/Core/Inc/stm32_si5351.h
+++ b/Core/Inc/stm32_si5351.h
@@ -108,12 +108,26 @@ typedef enum {
 #ifndef SI5351_NUMBER_OF_OUTPUTS
 #define SI5351_NUMBER_OF_OUTPUTS 8
 #endif
+
+#ifdef __arm__
+#ifdef __ARM_BIG_ENDIAN
+#define for_endian(size) for (int i = 0; i < size; ++i)
+#define last_loop_endian (i==size-1)
+#else
+#define for_endian(size) for (int i = size - 1; i >= 0; --i)
+#define last_loop_endian (i==0)
+#endif
+#else
+#error "Endianness not detected or another compiler"
+#endif
+
 /* Exported functions --------------------------------------------------------*/
 si5351_inst_t si5351_init(void * i2c_handle, uint32_t xtal_frequency, uint8_t i2c_address);
 int si5351_deinit(si5351_inst_t si5351_handle);
 int si5351_isready(si5351_inst_t inst);
 int si5351_program(si5351_inst_t inst);
 char * si5351_read_debug_msg(si5351_inst_t inst);
+char * si5351_read_register_debug(si5351_inst_t inst, char *buf, size_t bufsize, uint8_t regaddr);
 
 #ifdef __cplusplus
 } /* extern "C" */
diff --git a/Core/Inc/stm32_si5351_reg.h b/Core/Inc/stm32_si5351_reg.h
index e995efa..727694e 100644
--- a/Core/Inc/stm32_si5351_reg.h
+++ b/Core/Inc/stm32_si5351_reg.h
@@ -605,9 +605,6 @@ Synth1 divider. */
 /* #define SI5351_MULTISYNTH1_PARAMETER_2_LO_RESET_VALUE	0xXX */
 
 
-
-
-
 /* Multisynth2 Parameter 3.
 This 20-bit number is an encoded representation of the denominator for the frac-
 tional part of the MultiSynth2 Divider. */
@@ -714,9 +711,6 @@ Synth2 divider. */
 /* #define SI5351_MULTISYNTH2_PARAMETER_2_LO_RESET_VALUE	0xXX */
 
 
-
-
-
 /* Multisynth3 Parameter 3.
 This 20-bit number is an encoded representation of the denominator for the frac-
 tional part of the MultiSynth3 Divider. */
@@ -823,9 +817,6 @@ Synth3 divider. */
 /* #define SI5351_MULTISYNTH3_PARAMETER_2_LO_RESET_VALUE	0xXX */
 
 
-
-
-
 /* MULTISYNTH5 Parameter 3.
 This 20-bit number is an encoded representation of the denominator for the frac-
 tional part of the MultiSynth4 Divider. */
@@ -932,13 +923,6 @@ Synth3 divider. */
 /* #define SI5351_MULTISYNTH4_PARAMETER_2_LO_RESET_VALUE	0xXX */
 
 
-
-
-
-
-
-
-
 /* Multisynth5 Parameter 3.
 This 20-bit number is an encoded representation of the denominator for the frac-
 tional part of the MultiSynth5 Divider. */
@@ -1088,6 +1072,15 @@ even integers greater than or equal to 6. All other divide values are invalid. *
 #define R6_DIV_0		(1u<<4) /* 110b: Divide by 64, 111b: Divide by 128 */
 #define R6_DIV			(7u<<4)
 
+/* PLL Reset
+ * Resets the PLLA, PLLB when writing an 1 to the corresponding bit
+ * Leave the reserved bits as default.
+ * Note: 0x00001100 is my reset value for Si5351A 10-MSOP device
+ */
+#define SI5351_PLL_RESET		177u	/* R/W */
+#define SI5351_PLLB_RST	(1u<<7)	/*!< PLLB_Reset, writing a 1 to this bit will reset PLLB. This is a self clearing bit */
+#define SI5351_PLLA_RST	(1u<<5)	/*!< PLLA_Reset, writing a 1 to this bit will reset PLLA. This is a self clearing bit */
+#define SI5351_PLL_RESET_RESERVED (0x5F)	/*!< leave as default, not specified */
 
 /* Crystal Internal Load Capacitance
  * Two bits determine the internal load capacitance value for the crystal. See the Crystal
diff --git a/Core/Src/main.c b/Core/Src/main.c
index 152e5e2..1f430d4 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -142,11 +142,19 @@ int main(void)
 	  printf("Device No. %d (Instance No: 0x%x) is %s\n", i, (unsigned int) instance_si5351[i], (ready==0) ? "ready" : "N/A");
   }
 
-
+  puts("Registers of Device No. 1");
+  char buf[33]; //using uint8_t
+  //char buf[42]; //using uint16_t
+  //char buf[60]; //using uint32_t
+  //for (int i=0; i <= SI5351_FANOUT_ENABLE; i++) {
+  for (int i=0; i <= 255; i++) {
+	  puts(si5351_read_register_debug(instance_si5351[1], buf, sizeof(buf), i));
+  }
+/*
   status = si5351_program(instance_si5351[1]);
   printf("Device #1 gets status %d\n", status);
   printf("Debug:\n%s", si5351_read_debug_msg(instance_si5351[1]));
-
+*/
   for (int i=2; i>=0; i--) {
 	  si5351_deinit(instance_si5351[i]);
   }
diff --git a/Core/Src/stm32_si5351.c b/Core/Src/stm32_si5351.c
index 7931fd9..5da016c 100644
--- a/Core/Src/stm32_si5351.c
+++ b/Core/Src/stm32_si5351.c
@@ -19,6 +19,7 @@
 // @TODO try to get rid off including the HAL here, using pointer to the specified functions
 #if DEBUG
 #include <stdio.h>
+#include <string.h>
 #endif
 
 #include "stm32l4xx_hal.h"
@@ -39,6 +40,17 @@ typedef struct __SI5351_HandleTypeDef {
 	uint8_t		initialized:1;			/*!< mark the driver initialized	*/
 } si5351_HandleTypeDef;
 
+#ifndef __GNUC__ /*__arm__*/  /* Keil ARM compiler does not support typeof */
+#define snprintb(buf, n, value) __fprintb(buf, n, (uint32_t *)&value, sizeof(uint32_t))
+#define snprintb16(buf, n, value) __fprintb(buf, n, (uint16_t *)&value, sizeof(uint16_t))
+#define snprintb8(buf, n, value) __fprintb(buf, n, (uint8_t *)&value, sizeof(uint8_t))
+#else	/* for gcc, clang compilers */
+#define snprintb(buf, n, value)                                   \
+({                                                      \
+        typeof(value) _v = value;                       \
+        __snprintb(buf, n, (typeof(_v) *) &_v, sizeof(_v));       \
+})
+#endif
 /* Private define ------------------------------------------------------------*/
 #define	SI5351_VERSION	1
 
@@ -47,6 +59,7 @@ typedef struct __SI5351_HandleTypeDef {
 si5351_HandleTypeDef * first_handle = NULL;	/* pointer to the first instancee */
 int si5351_errno = 0;	/* error_number for functions whith return == NULL	  */
 /* Private function prototypes -----------------------------------------------*/
+int __fprintb(FILE *stream, void *value, size_t size);
 /* Private functions ---------------------------------------------------------*/
 
 /* wrapper function for receiving bytes from I2C bus
@@ -217,7 +230,7 @@ int si5351_program(si5351_inst_t inst) {
 			break;
 
 		/* power down all output drivers reg 16 -- 23 */
-		data = SI5351_CLKx_PDN;	// 0x80
+		data = SI5351_CLK0_PDN;	// 0x80
 #if OPTIMIZED
 		status = si5351_write(inst, SI5351_CLK0_CONTROL, &data, SI5351_NUMBER_OF_OUTPUTS);
 		if (status)
@@ -266,7 +279,6 @@ int si5351_program(si5351_inst_t inst) {
 #endif
 
 
-
 	} while(0);
 
 
@@ -282,6 +294,60 @@ char * si5351_read_debug_msg(si5351_inst_t inst) {
 	return inst->debug_msg;
 }
 
+/*!
+ * @brief Output the value in binary representation and in groups of
+ * bytes
+ *
+ * @param buf string of char * to output to
+ * @param n	amount of characters to output to
+ * @param value Value to output in binary representation
+ * @param size
+ * @return bytes written
+ */
+int __snprintb(char *buf, size_t n, void *value, size_t size)
+{
+	uint8_t byte;
+	size_t blen = sizeof(byte) * 8;
+	uint8_t bits[blen + 1];
+	int cx = 0;
+
+	bits[blen] = '\0';
+	for_endian(size) {
+		byte = ((uint8_t *) value)[i];
+		memset(bits, '0', blen);
+		for (int j = 0; byte && j < blen; ++j) {
+			if (byte & 0x80)
+				bits[j] = '1';
+			byte <<= 1;
+		}
+		cx += snprintf(buf+cx, n-cx, "%s%s", bits, (last_loop_endian)? "":" ");
+	}
+	return cx;
+}
+
+char * si5351_read_register_debug(si5351_inst_t inst, char *buf, size_t bufsize, uint8_t regaddr) {
+
+	uint8_t data;
+	// uint16_t data16;
+	// uint32_t data32;
+	int status;
+	int cx;
+
+	if (!inst)
+		return NULL;
+
+	status = si5351_read(inst, regaddr, &data, 1);
+	if (status)
+		return NULL;
+	// data16 = data;
+	// data32 = data;
+	cx = snprintf(buf, bufsize, "R%03u[0x%02x]=%3u[0x%02x][0b", regaddr, regaddr, data, data);
+	cx += snprintb(buf + cx, bufsize - cx, data);
+	// cx += snprintb(buf + cx, bufsize - cx, data32);
+	cx += snprintf(buf + cx, bufsize - cx, "]");
+	return buf;
+}
+
 #if 0
 
 int Si5351_WriteRegister(Si5351_ConfigTypeDef *Si5351_ConfigStruct,  uint8_t reg_address, uint8_t reg_data)