diff --git a/src/portable/espressif/esp32s2/dcd_esp32s2.c b/src/portable/espressif/esp32s2/dcd_esp32s2.c
index ade79f10..eb2c0515 100644
--- a/src/portable/espressif/esp32s2/dcd_esp32s2.c
+++ b/src/portable/espressif/esp32s2/dcd_esp32s2.c
@@ -382,16 +382,6 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
     num_packets++;
   }
 
-  // Set copy mode to constant address - required since data copied to or from the hardware USB FIFO needs to be written at a constant address
-  if (dir == TUSB_DIR_IN)
-  {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_CST);
-  }
-  else
-  {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_CST);
-  }
-
   ESP_LOGV(TAG, "Transfer <-> EP%i, %s, pkgs: %i, bytes: %i",
            epnum, ((dir == TUSB_DIR_IN) ? "USB0.HOST (in)" : "HOST->DEV (out)"),
            num_packets, total_bytes);
@@ -527,7 +517,7 @@ static void receive_packet(xfer_ctl_t *xfer, /* usb_out_endpoint_t * out_ep, */
   if (xfer->ff)
   {
     // Ring buffer
-    tu_fifo_write_n(xfer->ff, (const void *) rx_fifo, to_recv_size);
+    tu_fifo_write_n_const_addr(xfer->ff, (const void *) rx_fifo, to_recv_size);
   }
   else
   {
@@ -583,7 +573,7 @@ static void transmit_packet(xfer_ctl_t *xfer, volatile usb_in_endpoint_t *in_ep,
 
   if (xfer->ff)
   {
-    tu_fifo_read_n(xfer->ff, (void *) tx_fifo, to_xfer_size);
+    tu_fifo_read_n_const_addr(xfer->ff, (void *) tx_fifo, to_xfer_size);
   }
   else
   {
diff --git a/src/portable/microchip/samg/dcd_samg.c b/src/portable/microchip/samg/dcd_samg.c
index 5866e1ce..07ab9e83 100644
--- a/src/portable/microchip/samg/dcd_samg.c
+++ b/src/portable/microchip/samg/dcd_samg.c
@@ -312,14 +312,11 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
 
   if (dir == TUSB_DIR_OUT)
   {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_CST);
-
     // Enable interrupt when starting OUT transfer
     if (epnum != 0) UDP->UDP_IER |= (1 << epnum);
   }
   else
   {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_CST);
     tu_fifo_read_n(ff, (void *) &UDP->UDP_FDR[epnum], xfer_packet_len(xfer));
 
     // TX ready for transfer
@@ -440,7 +437,7 @@ void dcd_int_handler(uint8_t rhport)
           // write to EP fifo
           if (xfer->ff)
           {
-            tu_fifo_read_n(xfer->ff, (void *) &UDP->UDP_FDR[epnum], xact_len);
+            tu_fifo_read_n_const_addr(xfer->ff, (void *) &UDP->UDP_FDR[epnum], xact_len);
           }
           else
           {
@@ -473,7 +470,7 @@ void dcd_int_handler(uint8_t rhport)
         // Read from EP fifo
         if (xfer->ff)
         {
-          tu_fifo_write_n(xfer->ff, (const void *) &UDP->UDP_FDR[epnum], xact_len);
+          tu_fifo_write_n_const_addr(xfer->ff, (const void *) &UDP->UDP_FDR[epnum], xact_len);
         }
         else
         {
diff --git a/src/portable/nuvoton/nuc120/dcd_nuc120.c b/src/portable/nuvoton/nuc120/dcd_nuc120.c
index 0e7157d4..06ffa296 100644
--- a/src/portable/nuvoton/nuc120/dcd_nuc120.c
+++ b/src/portable/nuvoton/nuc120/dcd_nuc120.c
@@ -314,12 +314,10 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
 
   if (TUSB_DIR_IN == dir)
   {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_INC);      // For the PHY in nuc120 the source and destination pointer have to be incremented!
     dcd_in_xfer(xfer, ep);
   }
   else
   {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_INC);       // For the PHY in nuc120 the source and destination pointer have to be incremented!
     xfer->out_bytes_so_far = 0;
     ep->MXPLD = xfer->max_packet_size;
   }
diff --git a/src/portable/nuvoton/nuc121/dcd_nuc121.c b/src/portable/nuvoton/nuc121/dcd_nuc121.c
index 65a41463..6d98ba08 100644
--- a/src/portable/nuvoton/nuc121/dcd_nuc121.c
+++ b/src/portable/nuvoton/nuc121/dcd_nuc121.c
@@ -320,12 +320,10 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
 
   if (TUSB_DIR_IN == dir)
   {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_INC);      // For the PHY in nuc120 the source and destination pointer have to be incremented!
     dcd_in_xfer(xfer, ep);
   }
   else
   {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_INC);       // For the PHY in nuc120 the source and destination pointer have to be incremented!
     xfer->out_bytes_so_far = 0;
     ep->MXPLD = xfer->max_packet_size;
   }
diff --git a/src/portable/nuvoton/nuc505/dcd_nuc505.c b/src/portable/nuvoton/nuc505/dcd_nuc505.c
index 0d82a28c..5d15ca96 100644
--- a/src/portable/nuvoton/nuc505/dcd_nuc505.c
+++ b/src/portable/nuvoton/nuc505/dcd_nuc505.c
@@ -183,7 +183,7 @@ static void dcd_userEP_in_xfer(struct xfer_ctl_t *xfer, USBD_EP_T *ep)
   /* provided buffers are thankfully 32-bit aligned, allowing most data to be transfered as 32-bit */
   if (xfer->ff)
   {
-    tu_fifo_read_n(xfer->ff, (void *) (&ep->EPDAT_BYTE), bytes_now);
+    tu_fifo_read_n_const_addr(xfer->ff, (void *) (&ep->EPDAT_BYTE), bytes_now);
   }
   else
   {
@@ -431,12 +431,10 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
 
   if (TUSB_DIR_IN == dir)
   {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_CST);      // For the PHY in nuc505 the source and destination pointer have to be constant!
     ep->EPINTEN = USBD_EPINTEN_BUFEMPTYIEN_Msk;
   }
   else
   {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_CST);       // For the PHY in nuc505 the source and destination pointer have to be constant!
     xfer->out_bytes_so_far = 0;
     ep->EPINTEN = USBD_EPINTEN_RXPKIEN_Msk;
   }
@@ -659,7 +657,7 @@ void dcd_int_handler(uint8_t rhport)
           /* copy the data from the PC to the previously provided buffer */
           if (xfer->ff)
           {
-            tu_fifo_write_n(xfer->ff, (const void *) &ep->EPDAT_BYTE, tu_min16(available_bytes, xfer->total_bytes - xfer->out_bytes_so_far));
+            tu_fifo_write_n_const_addr(xfer->ff, (const void *) &ep->EPDAT_BYTE, tu_min16(available_bytes, xfer->total_bytes - xfer->out_bytes_so_far));
           }
           else
           {
diff --git a/src/portable/template/dcd_template.c b/src/portable/template/dcd_template.c
index ba656385..d8c8753d 100644
--- a/src/portable/template/dcd_template.c
+++ b/src/portable/template/dcd_template.c
@@ -105,7 +105,7 @@ bool dcd_edpt_xfer (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
   return false;
 }
 
-// Submit a transfer where is managed by FIFO, When complete dcd_event_xfer_complete() is invoked to notify the stack
+// Submit a transfer where is managed by FIFO, When complete dcd_event_xfer_complete() is invoked to notify the stack - optional, however, must be listed in usbd.c
 bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes)
 {
   (void) rhport;
diff --git a/src/portable/ti/msp430x5xx/dcd_msp430x5xx.c b/src/portable/ti/msp430x5xx/dcd_msp430x5xx.c
index a8da1ae4..40b12eb0 100644
--- a/src/portable/ti/msp430x5xx/dcd_msp430x5xx.c
+++ b/src/portable/ti/msp430x5xx/dcd_msp430x5xx.c
@@ -365,12 +365,10 @@ bool dcd_edpt_xfer_fifo (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16
 
   if(dir == TUSB_DIR_OUT)
   {
-    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_INC);       // For the PHY in msp430 the source and destination pointer have to be incremented!
     ep_regs[BCTX] &= ~NAK;
   }
   else
   {
-    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_INC);      // For the PHY in msp430 the source and destination pointer have to be incremented!
     USBIEPIFG |= (1 << epnum);
   }