diff --git a/CMSIS-DAP/Firmware/Include/DAP.h b/CMSIS-DAP/Firmware/Include/DAP.h
index 9d8f7fd..24e2462 100644
--- a/CMSIS-DAP/Firmware/Include/DAP.h
+++ b/CMSIS-DAP/Firmware/Include/DAP.h
@@ -236,6 +236,7 @@ typedef struct {
   uint8_t     fast_clock;                       // Fast Clock Flag
   uint8_t     padding[2];
   uint32_t   clock_delay;                       // Clock Delay
+  uint32_t   clock_freq;                        // Clock Frequency
   uint32_t     timestamp;                       // Last captured Timestamp
   struct {                                      // Transfer Configuration
     uint8_t   idle_cycles;                      // Idle cycles after transfer
diff --git a/CMSIS-DAP/Firmware/Source/DAP.c b/CMSIS-DAP/Firmware/Source/DAP.c
index 530236e..111a075 100644
--- a/CMSIS-DAP/Firmware/Source/DAP.c
+++ b/CMSIS-DAP/Firmware/Source/DAP.c
@@ -227,7 +227,7 @@ static uint32_t DAP_Connect(const uint8_t *request, uint8_t *response) {
   } else {
     port = *request;
   }
-  
+
   switch (port) {
 #if (DAP_SWD != 0)
     case DAP_PORT_SWD:
@@ -398,6 +398,7 @@ static uint32_t DAP_SWJ_Clock(const uint8_t *request, uint8_t *response) {
     return ((4U << 16) | 1U);
   }
 
+  DAP_Data.clock_freq = clock;
   if (clock >= MAX_SWJ_CLOCK(DELAY_FAST_CYCLES)) {
     DAP_Data.fast_clock  = 1U;
     DAP_Data.clock_delay = 1U;
diff --git a/CMSIS-DAP/Firmware/Source/DAP_vendor.c b/CMSIS-DAP/Firmware/Source/DAP_vendor.c
index a4ae496..11af5f2 100644
--- a/CMSIS-DAP/Firmware/Source/DAP_vendor.c
+++ b/CMSIS-DAP/Firmware/Source/DAP_vendor.c
@@ -45,7 +45,7 @@ file to the MDK-ARM project under the file group Configuration.
 \return          number of bytes in response (lower 16 bits)
                  number of bytes in request (upper 16 bits)
 */
-uint32_t DAP_ProcessVendorCommand(const uint8_t *request, uint8_t *response) {
+__WEAK uint32_t DAP_ProcessVendorCommand(const uint8_t *request, uint8_t *response) {
   uint32_t num = (1U << 16) | 1U;
 
   *response++ = *request;        // copy Command ID
diff --git a/CMSIS-DAP/Firmware/Source/JTAG_DP.c b/CMSIS-DAP/Firmware/Source/JTAG_DP.c
index 24b1f3f..5730f1b 100644
--- a/CMSIS-DAP/Firmware/Source/JTAG_DP.c
+++ b/CMSIS-DAP/Firmware/Source/JTAG_DP.c
@@ -75,7 +75,7 @@
 //   tdi:    pointer to TDI generated data
 //   tdo:    pointer to TDO captured data
 //   return: none
-void JTAG_Sequence (uint32_t info, const uint8_t *tdi, uint8_t *tdo) {
+__WEAK void JTAG_Sequence (uint32_t info, const uint8_t *tdi, uint8_t *tdo) {
   uint32_t i_val;
   uint32_t o_val;
   uint32_t bit;
@@ -264,7 +264,7 @@ JTAG_TransferFunction(Slow)
 
 // JTAG Read IDCODE register
 //   return: value read
-uint32_t JTAG_ReadIDCode (void) {
+__WEAK uint32_t JTAG_ReadIDCode (void) {
   uint32_t bit;
   uint32_t val;
   uint32_t n;
@@ -300,7 +300,7 @@ uint32_t JTAG_ReadIDCode (void) {
 // JTAG Write ABORT register
 //   data:   value to write
 //   return: none
-void JTAG_WriteAbort (uint32_t data) {
+__WEAK void JTAG_WriteAbort (uint32_t data) {
   uint32_t n;
 
   PIN_TMS_SET();
@@ -345,7 +345,7 @@ void JTAG_WriteAbort (uint32_t data) {
 // JTAG Set IR
 //   ir:     IR value
 //   return: none
-void JTAG_IR (uint32_t ir) {
+__WEAK void JTAG_IR (uint32_t ir) {
   if (DAP_Data.fast_clock) {
     JTAG_IR_Fast(ir);
   } else {
@@ -358,7 +358,7 @@ void JTAG_IR (uint32_t ir) {
 //   request: A[3:2] RnW APnDP
 //   data:    DATA[31:0]
 //   return:  ACK[2:0]
-uint8_t  JTAG_Transfer(uint32_t request, uint32_t *data) {
+__WEAK uint8_t  JTAG_Transfer(uint32_t request, uint32_t *data) {
   if (DAP_Data.fast_clock) {
     return JTAG_TransferFast(request, data);
   } else {
diff --git a/CMSIS-DAP/Firmware/Source/SW_DP.c b/CMSIS-DAP/Firmware/Source/SW_DP.c
index 803cf42..2e9087a 100644
--- a/CMSIS-DAP/Firmware/Source/SW_DP.c
+++ b/CMSIS-DAP/Firmware/Source/SW_DP.c
@@ -62,7 +62,7 @@
 //   data:   pointer to sequence bit data
 //   return: none
 #if ((DAP_SWD != 0) || (DAP_JTAG != 0))
-void SWJ_Sequence (uint32_t count, const uint8_t *data) {
+__WEAK void SWJ_Sequence (uint32_t count, const uint8_t *data) {
   uint32_t val;
   uint32_t n;
 
@@ -274,7 +274,7 @@ SWD_TransferFunction(Slow)
 //   request: A[3:2] RnW APnDP
 //   data:    DATA[31:0]
 //   return:  ACK[2:0]
-uint8_t  SWD_Transfer(uint32_t request, uint32_t *data) {
+__WEAK uint8_t  SWD_Transfer(uint32_t request, uint32_t *data) {
   if (DAP_Data.fast_clock) {
     return SWD_TransferFast(request, data);
   } else {