diff --git a/src/portable/nordic/nrf5x/dcd_nrf5x.c b/src/portable/nordic/nrf5x/dcd_nrf5x.c
index a78b74d62..b85d3776f 100644
--- a/src/portable/nordic/nrf5x/dcd_nrf5x.c
+++ b/src/portable/nordic/nrf5x/dcd_nrf5x.c
@@ -53,6 +53,9 @@ enum
 
 enum
 {
+  // Endpoint number is fixed (8) for ISOOUT and ISOIN.
+  EP_ISO_NUM = 8,
+  // CBI endpoints count
   EP_COUNT = 8
 };
 
@@ -67,6 +70,9 @@ typedef struct
   // nrf52840 will auto ACK OUT packet after DMA is done
   // indicate packet is already ACK
   volatile bool data_received;
+  // Set to true when data was transferred from RAM to ISO IN output buffer.
+  // New data can be put in ISO IN output buffer after SOF.
+  bool iso_in_transfer_ready;
 
 } xfer_td_t;
 
@@ -74,7 +80,8 @@ typedef struct
 static struct
 {
   // All 8 endpoints including control IN & OUT (offset 1)
-  xfer_td_t xfer[EP_COUNT][2];
+  // +1 for ISO endpoints
+  xfer_td_t xfer[EP_COUNT + 1][2];
 
   // Number of pending DMA that is started but not handled yet by dcd_int_handler().
   // Since nRF can only carry one DMA can run at a time, this value is normally be either 0 or 1.
@@ -173,6 +180,7 @@ static void xact_out_prepare(uint8_t epnum)
   {
     // Write zero value to SIZE register will allow hw to ACK (accept data)
     // If it is not already done by DMA
+    // SIZE.ISOOUT can also be accessed this way
     NRF_USBD->SIZE.EPOUT[epnum] = 0;
   }
 
@@ -183,15 +191,32 @@ static void xact_out_prepare(uint8_t epnum)
 static void xact_out_dma(uint8_t epnum)
 {
   xfer_td_t* xfer = get_td(epnum, TUSB_DIR_OUT);
+  uint32_t xact_len;
 
-  uint8_t const xact_len = NRF_USBD->SIZE.EPOUT[epnum];
+  if (epnum == EP_ISO_NUM)
+  {
+    xact_len = NRF_USBD->SIZE.ISOOUT;
+    // If ZERO bit is set, ignore ISOOUT length
+    if (xact_len & USBD_SIZE_ISOOUT_ZERO_Msk) xact_len = 0;
+    else
+    {
+      // Trigger DMA move data from Endpoint -> SRAM
+      NRF_USBD->ISOOUT.PTR = (uint32_t) xfer->buffer;
+      NRF_USBD->ISOOUT.MAXCNT = xact_len;
 
-  // Trigger DMA move data from Endpoint -> SRAM
-  NRF_USBD->EPOUT[epnum].PTR    = (uint32_t) xfer->buffer;
-  NRF_USBD->EPOUT[epnum].MAXCNT = xact_len;
+      edpt_dma_start(&NRF_USBD->TASKS_STARTISOOUT);
+    }
+  }
+  else
+  {
+    xact_len = (uint8_t)NRF_USBD->SIZE.EPOUT[epnum];
 
-  edpt_dma_start(&NRF_USBD->TASKS_STARTEPOUT[epnum]);
+    // Trigger DMA move data from Endpoint -> SRAM
+    NRF_USBD->EPOUT[epnum].PTR = (uint32_t) xfer->buffer;
+    NRF_USBD->EPOUT[epnum].MAXCNT = xact_len;
 
+    edpt_dma_start(&NRF_USBD->TASKS_STARTEPOUT[epnum]);
+  }
   xfer->buffer     += xact_len;
   xfer->actual_len += xact_len;
 }
@@ -296,14 +321,44 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
 
   _dcd.xfer[epnum][dir].mps = desc_edpt->wMaxPacketSize.size;
 
-  if ( dir == TUSB_DIR_OUT )
+  if (desc_edpt->bmAttributes.xfer != TUSB_XFER_ISOCHRONOUS)
   {
-    NRF_USBD->INTENSET = TU_BIT(USBD_INTEN_ENDEPOUT0_Pos + epnum);
-    NRF_USBD->EPOUTEN |= TU_BIT(epnum);
-  }else
+    if (dir == TUSB_DIR_OUT)
+    {
+      NRF_USBD->INTENSET = TU_BIT(USBD_INTEN_ENDEPOUT0_Pos + epnum);
+      NRF_USBD->EPOUTEN |= TU_BIT(epnum);
+    }else
+    {
+      NRF_USBD->INTENSET = TU_BIT(USBD_INTEN_ENDEPIN0_Pos + epnum);
+      NRF_USBD->EPINEN  |= TU_BIT(epnum);
+    }
+  }
+  else
   {
-    NRF_USBD->INTENSET = TU_BIT(USBD_INTEN_ENDEPIN0_Pos + epnum);
-    NRF_USBD->EPINEN  |= TU_BIT(epnum);
+    TU_ASSERT(epnum == EP_ISO_NUM);
+    if (dir == TUSB_DIR_OUT)
+    {
+      // SPLIT ISO buffer when ISO IN endpoint is already opened.
+      if (_dcd.xfer[EP_ISO_NUM][TUSB_DIR_IN].mps) NRF_USBD->ISOSPLIT = USBD_ISOSPLIT_SPLIT_HalfIN;
+      // Clear old events
+      NRF_USBD->EVENTS_ENDISOOUT = 0;
+      // Clear SOF event in case interrupt was not enabled yet.
+      if ((NRF_USBD->INTEN & USBD_INTEN_SOF_Msk) == 0) NRF_USBD->EVENTS_SOF = 0;
+      // Enable SOF and ISOOUT interrupts, and ISOOUT endpoint.
+      NRF_USBD->INTENSET = USBD_INTENSET_ENDISOOUT_Msk | USBD_INTENSET_SOF_Msk;
+      NRF_USBD->EPOUTEN |= USBD_EPOUTEN_ISOOUT_Msk;
+    }
+    else
+    {
+      NRF_USBD->EVENTS_ENDISOIN = 0;
+      // SPLIT ISO buffer when ISO OUT endpoint is already opened.
+      if (_dcd.xfer[EP_ISO_NUM][TUSB_DIR_OUT].mps) NRF_USBD->ISOSPLIT = USBD_ISOSPLIT_SPLIT_HalfIN;
+      // Clear SOF event in case interrupt was not enabled yet.
+      if ((NRF_USBD->INTEN & USBD_INTEN_SOF_Msk) == 0) NRF_USBD->EVENTS_SOF = 0;
+      // Enable SOF and ISOIN interrupts, and ISOIN endpoint.
+      NRF_USBD->INTENSET = USBD_INTENSET_ENDISOIN_Msk | USBD_INTENSET_SOF_Msk;
+      NRF_USBD->EPINEN  |= USBD_EPINEN_ISOIN_Msk;
+    }
   }
   __ISB(); __DSB();
 
@@ -317,16 +372,39 @@ void dcd_edpt_close (uint8_t rhport, uint8_t ep_addr)
   uint8_t const epnum = tu_edpt_number(ep_addr);
   uint8_t const dir   = tu_edpt_dir(ep_addr);
 
-  // CBI
-  if (dir == TUSB_DIR_OUT)
+  if (epnum != EP_ISO_NUM)
   {
-    NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPOUT0_Pos + epnum);
-    NRF_USBD->EPOUTEN &= ~TU_BIT(epnum);
+    // CBI
+    if (dir == TUSB_DIR_OUT)
+    {
+      NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPOUT0_Pos + epnum);
+      NRF_USBD->EPOUTEN &= ~TU_BIT(epnum);
+    }
+    else
+    {
+      NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPIN0_Pos + epnum);
+      NRF_USBD->EPINEN &= ~TU_BIT(epnum);
+    }
   }
   else
   {
-    NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPIN0_Pos + epnum);
-    NRF_USBD->EPINEN &= ~TU_BIT(epnum);
+    _dcd.xfer[EP_ISO_NUM][dir].mps = 0;
+    // ISO
+    if (dir == TUSB_DIR_OUT)
+    {
+      NRF_USBD->INTENCLR = USBD_INTENCLR_ENDISOOUT_Msk;
+      NRF_USBD->EPOUTEN &= ~USBD_EPOUTEN_ISOOUT_Msk;
+      NRF_USBD->EVENTS_ENDISOOUT = 0;
+    }
+    else
+    {
+      NRF_USBD->INTENCLR = USBD_INTENCLR_ENDISOIN_Msk;
+      NRF_USBD->EPINEN &= ~USBD_EPINEN_ISOIN_Msk;
+    }
+    // One of the ISO endpoints closed, no need to split buffers any more.
+    NRF_USBD->ISOSPLIT = USBD_ISOSPLIT_SPLIT_OneDir;
+    // When both ISO endpoint are close there is no need for SOF any more.
+    if (_dcd.xfer[EP_ISO_NUM][TUSB_DIR_IN].mps + _dcd.xfer[EP_ISO_NUM][TUSB_DIR_OUT].mps == 0) NRF_USBD->INTENCLR = USBD_INTENCLR_SOF_Msk;
   }
   __ISB(); __DSB();
 }
@@ -382,11 +460,12 @@ bool dcd_edpt_xfer (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
 void dcd_edpt_stall (uint8_t rhport, uint8_t ep_addr)
 {
   (void) rhport;
+  uint8_t const epnum = tu_edpt_number(ep_addr);
 
-  if ( tu_edpt_number(ep_addr) == 0 )
+  if ( epnum == 0 )
   {
     NRF_USBD->TASKS_EP0STALL = 1;
-  }else
+  }else if (epnum != EP_ISO_NUM)
   {
     NRF_USBD->EPSTALL = (USBD_EPSTALL_STALL_Stall << USBD_EPSTALL_STALL_Pos) | ep_addr;
   }
@@ -397,8 +476,9 @@ void dcd_edpt_stall (uint8_t rhport, uint8_t ep_addr)
 void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
 {
   (void) rhport;
+  uint8_t const epnum = tu_edpt_number(ep_addr);
 
-  if ( tu_edpt_number(ep_addr)  )
+  if ( epnum != 0 && epnum != EP_ISO_NUM )
   {
     // clear stall
     NRF_USBD->EPSTALL = (USBD_EPSTALL_STALL_UnStall << USBD_EPSTALL_STALL_Pos) | ep_addr;
@@ -456,8 +536,31 @@ void dcd_int_handler(uint8_t rhport)
     dcd_event_bus_signal(0, DCD_EVENT_BUS_RESET, true);
   }
 
+  // ISOIN: Data was moved to endpoint buffer, client will be notified in SOF
+  if ( int_status & USBD_INTEN_ENDISOIN_Msk )
+  {
+    xfer_td_t* xfer = get_td(EP_ISO_NUM, TUSB_DIR_IN);
+
+    xfer->actual_len = NRF_USBD->ISOIN.AMOUNT;
+    // Data transferred from RAM to endpoint output buffer.
+    // Next transfer can be scheduled after SOF.
+    xfer->iso_in_transfer_ready = true;
+  }
+
   if ( int_status & USBD_INTEN_SOF_Msk )
   {
+    // ISOOUT: Transfer data gathered in previous frame from buffer to RAM
+    if (NRF_USBD->EPOUTEN & USBD_EPOUTEN_ISOOUT_Msk)
+    {
+      xact_out_dma(EP_ISO_NUM);
+    }
+    // ISOIN: Notify client that data was transferred
+    xfer_td_t* xfer = get_td(EP_ISO_NUM, TUSB_DIR_IN);
+    if ( xfer->iso_in_transfer_ready )
+    {
+      xfer->iso_in_transfer_ready = false;
+      dcd_event_xfer_complete(0, EP_ISO_NUM | TUSB_DIR_IN_MASK, xfer->actual_len, XFER_RESULT_SUCCESS, true);
+    }
     dcd_event_bus_signal(0, DCD_EVENT_SOF, true);
   }
 
@@ -539,8 +642,11 @@ void dcd_int_handler(uint8_t rhport)
    * Note: Since nRF controller auto ACK next packet without SW awareness
    * We must handle this stage before Host -> Endpoint just in case
    * 2 event happens at once
+   * ISO OUT: Transaction must fit in single packed, it can be shorter then total
+   * len if Host decides to sent fewer bytes, it this case transaction is also
+   * complete and next transfer is not initiated here like for CBI.
    */
-  for(uint8_t epnum=0; epnum<8; epnum++)
+  for(uint8_t epnum=0; epnum<EP_COUNT+1; epnum++)
   {
     if ( tu_bit_test(int_status, USBD_INTEN_ENDEPOUT0_Pos+epnum))
     {
@@ -551,7 +657,7 @@ void dcd_int_handler(uint8_t rhport)
       xfer->data_received = false;
 
       // Transfer complete if transaction len < Max Packet Size or total len is transferred
-      if ( (xact_len == xfer->mps) && (xfer->actual_len < xfer->total_len) )
+      if ( (epnum != EP_ISO_NUM) && (xact_len == xfer->mps) && (xfer->actual_len < xfer->total_len) )
       {
         // Prepare for next transaction
         xact_out_prepare(epnum);