Diff: USBDevice/USBHAL_KL25Z.cpp

Revision:

37:c5ac4ccf6597

Parent:

36:20bb47609697

Child:

38:072e12583e73

--- a/USBDevice/USBHAL_KL25Z.cpp	Tue Jan 05 05:22:50 2016 +0000
+++ b/USBDevice/USBHAL_KL25Z.cpp	Mon Jan 11 21:07:25 2016 +0000
@@ -16,160 +16,148 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-#define DEBUG_PRINTF // enable debug messages
+#if defined(TARGET_KL25Z) | defined(TARGET_KL46Z) | defined(TARGET_K20D5M) | defined(TARGET_K64F)
 
-#if defined(TARGET_KL25Z) | defined(TARGET_KL46Z) | defined(TARGET_K20D5M) | defined(TARGET_K64F)
+//#define DEBUG
+#ifdef DEBUG
+#define printd(fmt, ...) printf(fmt, __VA_ARGS__)
+#else
+#define printd(fmt, ...)
+#endif
+
 
 #include "USBHAL.h"
 
+// Critical section controls.  This module uses a bunch of static variables,
+// and much of the code that accesses the statics can be called from either
+// normal application context or IRQ context.  Whenever a shared variable is
+// accessed from code that can run in an application context, we have to
+// protect against interrupts by entering a critical section.  These macros
+// enable and disable the USB IRQ if we're running in application context.
+// (They do nothing if we're already in interrupt context, because the
+// hardware interrupt controller won't generated another of the same IRQ
+// that we're already handling.  We could still be interrupted by a different,
+// higher-priority IRQ, but our shared variables are only shared within this
+// module, so they won't be affected by other interrupt handlers.)
+static int inIRQ;
+#define ENTER_CRITICAL_SECTION \
+    if (!inIRQ) \
+        NVIC_DisableIRQ(USB0_IRQn);
+#define EXIT_CRITICAL_SECTION \
+    if (!inIRQ) \
+        NVIC_EnableIRQ(USB0_IRQn);
+
+// static singleton instance pointer
 USBHAL * USBHAL::instance;
 
-// DMAERR has occurred
-bool USB_DMAERR;
-
-
-// Perform an operation atomically, by disabling interrupts.  This must be
-// used for any test-and-write operations in non-IRQ code, including increment, 
-// decrement, bit set, and bit clear, on variables that are also written 
-// within the IRQ handler.  (Operations *within* the IRQ handler don't require 
-// this, because regular code can't interrupt an interrupt handler.)  This
-// applies in particular to 'epComplete' and 'Data1' updates, which are both
-// bit vectors that are written with bitwise test-and-set operations in
-// regular code and IRQ code.
-#define atomic(_stm_) \
-    do { \
-        NVIC_DisableIRQ(USB0_IRQn); \
-        _stm_; \
-        NVIC_EnableIRQ(USB0_IRQn); \
-    } while (0)
-    
 // Convert physical endpoint number to register bit
 #define EP(endpoint) (1<<(endpoint))
 
-// Convert physical to logical
+// Convert physical endpoint number to logical endpoint number.
+// Each logical endpoint has two physical endpoints, one RX and 
+// one TX.  The physical endpoints are numbered in RX,TX pairs,
+// so the logical endpoint number is simply the physical endpoint
+// number divided by 2 (discarding the remainder).
 #define PHY_TO_LOG(endpoint)    ((endpoint)>>1)
 
-// Get endpoint direction
+// Get a physical endpoint's direction.  IN and OUT are from
+// the host's perspective, so from our perspective on the device,
+// IN == TX and OUT == RX.  The physical endpoints are in RX,TX
+// pairs, so the OUT/RX is the even numbered element of a pair
+// and the IN/TX is the odd numbered element.
 #define IN_EP(endpoint)     ((endpoint) & 1U ? true : false)
 #define OUT_EP(endpoint)    ((endpoint) & 1U ? false : true)
 
-#define BD_OWN_MASK        (1<<7)
-#define BD_DATA01_MASK     (1<<6)
-#define BD_KEEP_MASK       (1<<5)
-#define BD_NINC_MASK       (1<<4)
-#define BD_DTS_MASK        (1<<3)
-#define BD_STALL_MASK      (1<<2)
+// BDT status flags, defined by the SIE hardware.  These are
+// bits packed into the 'info' byte of a BDT entry.
+#define BD_OWN_MASK        (1<<7)       // OWN - hardware SIE owns the BDT (TX/RX in progress)
+#define BD_DATA01_MASK     (1<<6)       // DATA01 - DATA0/DATA1 bit for current TX/RX on endpoint
+#define BD_KEEP_MASK       (1<<5)       // KEEP - hardware keeps BDT ownership after token completes
+#define BD_NINC_MASK       (1<<4)       // NO INCREMENT - buffer location is a FIFO, so use same address for all bytes
+#define BD_DTS_MASK        (1<<3)       // DATA TOGGLE SENSING - hardware SIE checks for DATA0/DATA1 match during RX/TX
+#define BD_STALL_MASK      (1<<2)       // STALL - SIE issues STALL handshake in reply to any host access to endpoint
 
-// Endpoint direction.  These are relative to the DEVICE:
-//  TX = transmit to host = "IN" endpoint
-//  RX = receive from host = "OUT" endpoint
+// Endpoint direction
 #define TX    1
 #define RX    0
 
-// Double-buffering parity.  The hadrware SIE has a native double-buffering
-// scheme that switches back and forth between two buffers per physical
-// endpoint.  We disable this feature, so we effectively only use the EVEN
-// buffer for each endpoint.
+// Buffer parity.  The hardware has a double-buffering scheme where each
+// physical endpoint has two associated BDT entries, labeled EVEN and ODD.
+// We disable the double buffering, so only the EVEN buffers are used in
+// this implementation.
 #define EVEN  0
 #define ODD   1
 
-// Get the BDT index for a given endpoint.  'logep' is the LOGICAL
-// endpoint number; 'dir' is the direction (TX or RX).  'odd' is
-// the even/odd flag for the hardware SIE double-buffering system.
-// We don't actually use the double-buffering scheme, so this is 
-// essentially always EVEN throughout this implementation.
-#define EP_BDT_IDX(logep, dir, odd) ((4*(logep)) + (2*(dir)) + (1*(odd)))
+// Get the BDT index for a given logical endpoint, direction, and buffer parity
+#define EP_BDT_IDX(logep, dir, odd) (((logep) * 4) + (2 * (dir)) + (1 *  (odd)))
 
-// get the BDT for a given physical endpoint
-#define PEP_BDT_IDX(phyep, odd) ((2*(phyep)) + (1*(odd)))
+// Get the BDT index for a given physical endpoint and buffer parity
+#define PEP_BDT_IDX(phyep, odd)  (((phyep) * 2) + (1 * (odd)))
 
-
+// Token types reported in the BDT 'info' flags.  
+#define TOK_PID(idx)   ((bdt[idx].info >> 2) & 0x0F)
 #define SETUP_TOKEN    0x0D
 #define IN_TOKEN       0x09
 #define OUT_TOKEN      0x01
-#define TOK_PID(idx)   ((bdt[idx].info >> 2) & 0x0F)
 
-
-// Buffer Descriptor Table (BDT) entry.
-//
-// Each entry in the BDT uses this structure, which is defined by
-// the hardware SIE design.
+// Buffer Descriptor Table (BDT) entry.  This is the hardware-defined
+// memory structure for the shared memory block controlling an endpoint.
 typedef struct BDT {
     uint8_t   info;       // BD[0:7]
     uint8_t   dummy;      // RSVD: BD[8:15]
-    uint16_t  byte_count; // BD[16:25] reserved[26:31]
+    uint16_t  byte_count; // BD[16:32]
     uint32_t  address;    // Addr
-} __attribute__((packed)) BDT;
+} BDT;
 
-// The Buffer Descriptor Table is a contiguous block of BDT entries
-// (the structure defined above).  This memory block is shared with the
-// hardware SIE to coordinate endpoint send/receive operations between
-// the hardware and software.  The hardware design requires this block
-// to be aligned on a 512-byte boundary; the location of the block is
-// stored in a hardware register that we set during initialization.
-//
 // There are:
-//    * 16 logical endpoints (EP0 .. EP15)
-//    * 2 physical endpoints (TX and RX) per logical endpoint -> 32 physical endpoints
-//    * two buffers per physical endpoint (EVEN and ODD) -> 64 buffers
+//    * 16 bidirectional logical endpoints -> 32 physical endpoints
+//    * 2 BDT entries per endpoint (EVEN/ODD) -> 64 BDT entries
 __attribute__((__aligned__(512))) BDT bdt[NUMBER_OF_PHYSICAL_ENDPOINTS * 2];
+
+// Transfer buffers.  We allocate the transfer buffers and point the
+// SIE hardware to them via the BDT.  We disable hardware SIE's
+// double-buffering (EVEN/ODD) scheme, so we only allocate one buffer
+// per physical endpoint.
 uint8_t *endpoint_buffer[NUMBER_OF_PHYSICAL_ENDPOINTS];
 
-// The device's bus address
+// Allocated size of each endpoint buffer
+size_t epMaxPacket[NUMBER_OF_PHYSICAL_ENDPOINTS];
+
+// SET ADDRESS mode tracking.  The address assignment has to be done in a
+// specific order and with specific timing defined by the USB setup protocol 
+// standards.  To get the sequencing right, we set a flag when we get the
+// address message, and then set the address in the SIE when we're at the 
+// right subsequent packet step in the protocol exchange.  These variables
+// are just a place to stash the information between the time we receive the
+// data and the time we're ready to update the SIE register.
+static uint8_t set_addr = 0;
 static uint8_t addr = 0;
 
-// Mode flag indicating that the host will send our assigned address
-// in the next packet
-static uint8_t set_addr = 0;
+// Endpoint DATA0/DATA1 bits, packed as a bit vector.  Each endpoint's
+// bit is at (1 << endpoint number).  These track the current bit value
+// on the endpoint.  For TX endpoints, this is the bit for the LAST
+// packet we sent (so the next packet will be the inverse).  For RX
+// endpoints, this is the bit value we expect for the NEXT packet.
+// (Yes, it's inconsistent.)
+static uint32_t Data1  = 0x55555555;
 
-// Private data per endpoint
-struct {
-    uint32_t flags;     // flags set when endpoint was realized
-    uint32_t bufsiz;    // allocated buffer size for endpoint
-} epInfo[NUMBER_OF_PHYSICAL_ENDPOINTS];
-    
-// Endpoint completion flags (one for each endpoint).  These flags indicate
-// if the last read or write operation on an endpoint has completed.  It's 
-// set by the interrupt handler when a send/receive operation completes.  
-// It's cleared by the readResult/writeResult routines on retrieving a 
-// successful completion status.
+// Endpoint read/write completion flags, packed as a bit vector.  Each 
+// endpoint's bit is at (1 << endpoint number).  A 1 bit signifies that
+// the last read or write has completed (and hasn't had its result 
+// consumed yet).
 static volatile int epComplete = 0;
 
-// clear a completion flag - must be atomic, as the IRQ also manipulates these bits
-#define clear_completion(endpoint) atomic(epComplete &= ~EP(endpoint))
-    
-// Endpoint ready flags.  These indicate if endpoints are ready for their
-// next read/write operations.  These are set by the read/write routines, and
-// cleared by the interrupt handler.  Note that these are *almost* the
-// inverse of the epComplete flags, but not quite: these aren't consumed by
-// the status checks.  We use these to check for clearance before starting an
-// operation, to make sure we're not attempting to overwrite a previous one.
-static volatile uint32_t epReady = 0;
-
-// set/clear the ready flag - must be atomic, as the IRQ also manipulates these bits
-#define set_ready(endpoint) atomic(epReady |= EP(endpoint))
-#define clear_ready(endpoint) atomic(epReady &= ~EP(endpoint))
-
-
-// DATA0/DATA1 setting for next packet on each endpoint
-static volatile uint32_t Data1  = 0x55555555;
-
-// set DATA0/DATA1 status on an endpoint (must be atomic as the IRQ handler
-// manpulates this variable)
-#define set_DATA0(endpoint) atomic(Data1 &= ~EP(endpoint))
-#define set_DATA1(endpoint) atomic(Data1 |= EP(endpoint))
-#define toggle_DATA01(endpoint) atomic(Data1 ^= EP(endpoint))
-
-static uint32_t frameNumber() {
+static uint32_t frameNumber() 
+{
     return((USB0->FRMNUML | (USB0->FRMNUMH << 8)) & 0x07FF);
 }
 
-uint32_t USBHAL::endpointReadcore(uint8_t endpoint, uint8_t *buffer) {
+uint32_t USBHAL::endpointReadcore(uint8_t endpoint, uint8_t *buffer) 
+{
     return 0;
 }
 
-USBHAL::USBHAL(void) 
-{
+USBHAL::USBHAL(void) {
     // Disable IRQ
     NVIC_DisableIRQ(USB0_IRQn);
 
@@ -214,45 +202,47 @@
     // enable OTG clock
     SIM->SCGC4 |= SIM_SCGC4_USBOTG_MASK;
 
+    // Attach IRQ
+    instance = this;
+    NVIC_SetVector(USB0_IRQn, (uint32_t)&_usbisr);
+    NVIC_EnableIRQ(USB0_IRQn);
+
     // USB Module Configuration
     // Reset USB Module
     USB0->USBTRC0 |= USB_USBTRC0_USBRESET_MASK;
     while(USB0->USBTRC0 & USB_USBTRC0_USBRESET_MASK);
 
     // Set BDT Base Register
-    USB0->BDTPAGE1 = (uint8_t)(uint32_t(bdt) >> 8);
-    USB0->BDTPAGE2 = (uint8_t)(uint32_t(bdt) >> 16);
-    USB0->BDTPAGE3 = (uint8_t)(uint32_t(bdt) >> 24);
+    USB0->BDTPAGE1 = (uint8_t)((uint32_t)bdt>>8);
+    USB0->BDTPAGE2 = (uint8_t)((uint32_t)bdt>>16);
+    USB0->BDTPAGE3 = (uint8_t)((uint32_t)bdt>>24);
 
     // Clear interrupt flag
     USB0->ISTAT = 0xff;
 
     // USB Interrupt Enablers
-    USB0->INTEN = USB_INTEN_TOKDNEEN_MASK |
-                  USB_INTEN_SOFTOKEN_MASK |
-                  USB_INTEN_ERROREN_MASK  |
-                  USB_INTEN_SLEEPEN_MASK |
-                  USB_INTEN_RESUMEEN_MASK |
-                  USB_INTEN_USBRSTEN_MASK |
-                  (1 << 7);                   // stall mask
-
-    // Attach IRQ
-    instance = this;
-    NVIC_SetVector(USB0_IRQn, (uint32_t)&_usbisr);
-    NVIC_EnableIRQ(USB0_IRQn);
+    USB0->INTEN |= USB_INTEN_TOKDNEEN_MASK |
+                   USB_INTEN_SOFTOKEN_MASK |
+                   USB_INTEN_ERROREN_MASK  |
+                   USB_INTEN_SLEEPEN_MASK |
+                   USB_INTEN_RESUMEEN_MASK |
+                   USB_INTEN_USBRSTEN_MASK;
 
     // Disable weak pull downs
     USB0->USBCTRL &= ~(USB_USBCTRL_PDE_MASK | USB_USBCTRL_SUSP_MASK);
+
     USB0->USBTRC0 |= 0x40;
 }
 
-USBHAL::~USBHAL(void) { }
+USBHAL::~USBHAL(void) 
+{ 
+}
 
 void USBHAL::connect(void) 
 {
     // enable USB
     USB0->CTL |= USB_CTL_USBENSOFEN_MASK;
-    
+
     // Pull up enable
     USB0->CONTROL |= USB_CONTROL_DPPULLUPNONOTG_MASK;
 }
@@ -266,21 +256,28 @@
     USB0->CONTROL &= ~USB_CONTROL_DPPULLUPNONOTG_MASK;
 
     //Free buffers if required:
-    for (int i = 0 ; i < NUMBER_OF_PHYSICAL_ENDPOINTS ; i++) {
-        free(endpoint_buffer[i]);
-        endpoint_buffer[i] = NULL;
+    for (int i = 0 ; i < NUMBER_OF_PHYSICAL_ENDPOINTS ; i++) 
+    {
+        if (endpoint_buffer[i] != NULL)
+        {
+            free(endpoint_buffer[i]);
+            endpoint_buffer[i] = NULL;
+        }
     }
 }
 
-void USBHAL::configureDevice(void) {
+void USBHAL::configureDevice(void) 
+{
     // not needed
 }
 
-void USBHAL::unconfigureDevice(void) {
+void USBHAL::unconfigureDevice(void) 
+{
     // not needed
 }
 
-void USBHAL::setAddress(uint8_t address) {
+void USBHAL::setAddress(uint8_t address) 
+{
     // we don't set the address now otherwise the usb controller does not ack
     // we set a flag instead
     // see usbisr when an IN token is received
@@ -290,73 +287,74 @@
 
 bool USBHAL::realiseEndpoint(uint8_t endpoint, uint32_t maxPacket, uint32_t flags) 
 {
-    uint32_t handshake_flag;
-    uint32_t alo_size;
-
+    // validate the endpoint number
     if (endpoint >= NUMBER_OF_PHYSICAL_ENDPOINTS)
         return false;
 
+    // get the logical endpoint
     uint32_t log_endpoint = PHY_TO_LOG(endpoint);
     
-    if (flags & ISOCHRONOUS) {
-        handshake_flag = 0;
-        alo_size = 1023;
-    }
-    else {
-        handshake_flag = USB_ENDPT_EPHSHK_MASK;
-        alo_size = 64;
-    }
-    
-    // if we have a buffer, but the new buffer size is bigger, delete the old one
-    if (endpoint_buffer[endpoint] != 0 && epInfo[endpoint].bufsiz < maxPacket) {
-        free(endpoint_buffer[endpoint]);
-        endpoint_buffer[endpoint] = 0;
-        epInfo[endpoint].bufsiz = 0;
-    }
-    
-    // allocate a new buffer if we don't already have one    
-    if (endpoint_buffer[endpoint] == 0) {
-        endpoint_buffer[endpoint] = (uint8_t *)malloc(alo_size);
-        epInfo[endpoint].bufsiz = alo_size;
-    }
-    
-    // remember the realisation flags for the endpoint
-    epInfo[endpoint].flags = flags;
+    // Constrain the requested packet size to the maximum for the endpoint type.
+    // Full Speed USB allows up to 1023 bytes for isochronous endpoints and 64 bytes
+    // for bulk and interrupt endpoints.
+    uint32_t realMaxPacket = ((flags & ISOCHRONOUS) ? 1023 : 64);
+    if (maxPacket > realMaxPacket)
+        maxPacket = realMaxPacket;
+
+    // Use the HANDSHAKE flag for non-isochronous endpoints.  Don't use handshaking
+    // for an iso endpoint, since this type of endpoint is for applications like
+    // audio and video streaming where it's preferable to ignore lost packets and
+    // just carry on with the latest data.
+    uint32_t ctlFlags = 0;
+    if (!(flags & ISOCHRONOUS))
+        ctlFlags |= USB_ENDPT_EPHSHK_MASK;
+        
+    // figure the RX/TX based on the endpoint direction
+    ctlFlags |= (IN_EP(endpoint) ? USB_ENDPT_EPTXEN_MASK : USB_ENDPT_EPRXEN_MASK);
 
-    // Set DATA1 initially on the endpoint.  If it's an RX endpoint, we're about to start
-    // a read with DATA0, so the next read will be DATA1.  If it's a TX endpoint, we'll
-    // actually want to send DATA0 for the first packet, but for that we need the flag
-    // to be set to DATA1, since the write routine always inverts the flag *before*
-    // using it.
-    set_DATA1(endpoint);
-    
-    // the endpoint hasn't completed its first operation yet
-    clear_completion(endpoint);
-    
-    if (IN_EP(endpoint)) 
+    ENTER_CRITICAL_SECTION
     {
-        // IN endpt -> device to host (TX)
-        set_ready(endpoint);
-        USB0->ENDPOINT[log_endpoint].ENDPT |= handshake_flag |        // ep handshaking (not if iso endpoint)
-                                              USB_ENDPT_EPTXEN_MASK;  // en TX (IN) tran
-        bdt[EP_BDT_IDX(log_endpoint, TX, EVEN)].info       = 0;
-        bdt[EP_BDT_IDX(log_endpoint, TX, ODD )].info       = 0;
-        bdt[EP_BDT_IDX(log_endpoint, TX, EVEN)].address = (uint32_t) endpoint_buffer[endpoint];
-        bdt[EP_BDT_IDX(log_endpoint, TX, ODD )].address = 0;
+        // if we don't already have a buffer that's big enough, allocate a new one
+        uint8_t *buf = endpoint_buffer[endpoint];
+        if (maxPacket > epMaxPacket[endpoint])
+        {
+            // free any existing buffer
+            if (buf != 0)
+                free(buf);
+                
+            // allocate a new one
+            epMaxPacket[endpoint] = maxPacket;
+            endpoint_buffer[endpoint] = buf = (uint8_t *)malloc(maxPacket);
+        }
+        
+        // Set up the BDT entry.  Note that we disable the hardware double-buffering
+        // scheme, so we only use the EVEN buffer for the endpoint.
+        int idx = PEP_BDT_IDX(endpoint, EVEN);
+        bdt[idx].info = 0;
+        bdt[idx].address = (uint32_t)buf;
+        
+        // Set the endpoint flags.  Note that these bits are additive, since the
+        // endpoint register represents the logical endpoint, which is the combination
+        // of the physical IN and OUT endpoints.
+        USB0->ENDPOINT[log_endpoint].ENDPT |= ctlFlags;
+    
+        // If this is an OUT endpoint, queue the first read on the endpoint by
+        // handing ownership of the BDT to the SIE.
+        if (OUT_EP(endpoint))
+        {
+            bdt[idx].byte_count = maxPacket;
+            bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK;
+        }
+    
+        // Set DATA1 on the endpoint.  For RX endpoints, we just queued up our first
+        // read, which will always be a DATA0 packet, so the next read will use DATA1.
+        // For TX endpoints, we always flip the bit *before* sending the packet, so
+        // (counterintuitively) we need to set the DATA1 bit now to send DATA0 in the
+        // next packet.  So in either case, we want DATA1 initially.
+        Data1 |= (1 << endpoint);
     }
-    else 
-    {
-        // OUT endpt -> host to device (RX)
-        clear_ready(endpoint);
-        USB0->ENDPOINT[log_endpoint].ENDPT |= handshake_flag |        // ep handshaking (not if iso endpoint)
-                                              USB_ENDPT_EPRXEN_MASK;  // en RX (OUT) tran.
-        bdt[EP_BDT_IDX(log_endpoint, RX, EVEN)].byte_count = maxPacket;
-        bdt[EP_BDT_IDX(log_endpoint, RX, EVEN)].address    = (uint32_t) endpoint_buffer[endpoint];
-        bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].address    = 0;
-        bdt[EP_BDT_IDX(log_endpoint, RX, EVEN)].info       = BD_OWN_MASK | BD_DTS_MASK;
-        bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].info       = 0;
-    }
-
+    EXIT_CRITICAL_SECTION
+    
     // success
     return true;
 }
@@ -365,270 +363,212 @@
 void USBHAL::EP0setup(uint8_t *buffer) 
 {
     uint32_t sz;
-    if (endpointReadResult(EP0OUT, buffer, &sz) != EP_COMPLETED)
-        printf("EP0setup not ready\r\n"); // $$$
-    if (sz != 8) 
-        printf("EP0setup - wrong size! %d bytes, expected 8 bytes\r\n", sz); // $$$
+    endpointReadResult(EP0OUT, buffer, &sz);
 }
 
 void USBHAL::EP0readStage(void) 
 {
-    uint32_t idx = EP_BDT_IDX(PHY_TO_LOG(EP0OUT), RX, 0);
-    set_DATA0(EP0OUT);                              // set DATA0 for the next packet
-    { // if (epReady & EP(EP0OUT)) {
-        bdt[idx].byte_count = MAX_PACKET_SIZE_EP0;
-        bdt[idx].info = (BD_DTS_MASK | BD_OWN_MASK);    // start the read
+    if (!(bdt[0].info & BD_OWN_MASK))
+    {
+        Data1 &= ~1UL;  // set DATA0
+        bdt[0].byte_count = MAX_PACKET_SIZE_EP0;
+        bdt[0].info = (BD_DTS_MASK | BD_OWN_MASK);
     }
-#ifdef DEBUG_PRINTF
- //   else printf("!!! EP0readStage() not ready !!!\r\n");
-#endif
 }
 
 void USBHAL::EP0read(void) 
 {
+    if (!bdt[0].info & BD_OWN_MASK)
+        bdt[0].byte_count = MAX_PACKET_SIZE_EP0;
 }
 
 uint32_t USBHAL::EP0getReadResult(uint8_t *buffer) 
 {
     uint32_t sz;
-    while (endpointReadResult(EP0OUT, buffer, &sz) == EP_PENDING) ;
+    endpointReadResult(EP0OUT, buffer, &sz);
     return sz;
 }
 
-void USBHAL::EP0write(uint8_t *buffer, uint32_t size) {
-    while (endpointWrite(EP0IN, buffer, size) == EP_BUSY) ;
+void USBHAL::EP0write(uint8_t *buffer, uint32_t size) 
+{
+    endpointWrite(EP0IN, buffer, size);
 }
 
-void USBHAL::EP0getWriteResult(void) {
+void USBHAL::EP0getWriteResult(void) 
+{
 }
 
 void USBHAL::EP0stall(void) 
 {
+    printd("EP0 stall!\r\n");
     stallEndpoint(EP0OUT);
 }
 
 EP_STATUS USBHAL::endpointRead(uint8_t endpoint, uint32_t maximumSize) 
 {
+    // We always start a new read when we fetch the result of the
+    // previous read, so we don't have to do anything here.  Simply
+    // indicate that the read is pending so that the caller can proceed
+    // to check the results.
     return EP_PENDING;
 }
 
 EP_STATUS USBHAL::endpointReadResult(uint8_t endpoint, uint8_t *buffer, uint32_t *bytesRead) 
 {
-    // validate the endpoint number
-    if (endpoint >= NUMBER_OF_PHYSICAL_ENDPOINTS)
+    // validate the endpoint number and direction
+    if (endpoint >= NUMBER_OF_PHYSICAL_ENDPOINTS || !OUT_EP(endpoint))
         return EP_INVALID;
 
-    // we can only read an OUT endpoint
-    if (IN_EP(endpoint))
-        return EP_INVALID;
-
-    // get the logical endpoint number
+    // get the logical endpoint
     uint32_t log_endpoint = PHY_TO_LOG(endpoint);
-
+    
+    // get the mode - it's isochronous if it doesn't have the handshake flag
+    bool iso = !(USB0->ENDPOINT[log_endpoint].ENDPT & USB_ENDPT_EPHSHK_MASK);
+    
     // get the BDT index
     int idx = EP_BDT_IDX(log_endpoint, RX, 0);
- 
-#if 1 // $$$$   
-#ifdef DEBUG_PRINTF
-    if (endpoint == EP0OUT && !(epReady & EP(endpoint))) printf("!!! EP0 read not ready\r\n");
-#endif
-    // if the endpoint isn't ready, the read is pending
-    if (!(epReady & EP(endpoint)))
+        
+    // If the "complete" flag isn't set, the read is still pending in the SIE.
+    // This doesn't apply the isochronous endpoints, since we don't get TOKDNE
+    // interrupts on those (we use the SOF signal instead).  It also doesn't
+    // apply to endpoint 0, since that doesn't use the epComplete mechanism
+    // at all (necessary because we handle all transactions on this endpoint
+    //  in IRQ context).  For EP0, just make sure the hardware doesn't still
+    // own the BDT - if it does, the last read hasn't completed yet.
+    if (log_endpoint == 0)
+    {
+        // control endpoint - just make sure we own the BDT
+        if (bdt[idx].info & BD_OWN_MASK)
+            return EP_PENDING;
+    }
+    else if (!iso && !(epComplete & EP(endpoint)))
         return EP_PENDING;
-#else
-    // If the endpoint isn't ready, the read is still pending.  Ignore this
-    // for EP0, since the control procotol inherently serializes packets on
-    // both the RX and TX endpoints.
-    if (endpoint != EP0OUT && !(epReady & EP(endpoint)))
-        return EP_PENDING;
-#endif
+    
+    // get the buffer
+    uint8_t *ep_buf = endpoint_buffer[endpoint];
 
-    // make sure we're marked as complete (except for isochronous endpoints)
-    bool iso = epInfo[log_endpoint].flags & ISOCHRONOUS;
-    if ((log_endpoint != 0) && !iso && !(epComplete & EP(endpoint)))
-        return EP_PENDING;
-
-    // this consumes the read status - clear the completion flag to prepare for the next read
-    clear_completion(endpoint);
+    ENTER_CRITICAL_SECTION
+    {
+        // get the packet size from the BDT
+        uint32_t sz  = bdt[idx].byte_count;
     
-    // the new operation is pending, so the endpoint is not ready
-    clear_ready(endpoint);
-
-    // copy the data from the hardware buffer to the caller's buffer
-    uint8_t *ep_buf = (uint8_t *)bdt[idx].address;
-    uint32_t sz = *bytesRead = bdt[idx].byte_count;
-    for (uint32_t n = 0; n < sz; n++)
-        buffer[n] = ep_buf[n];
+        // note if it's a SETUP token    
+        bool setup = (log_endpoint == 0 && TOK_PID(idx) == SETUP_TOKEN);
     
-    // Figure the DATA0/DATA1 value for the next packet.  If we have a
-    // SETUP token with no data stage, it's DATA0.  Otherwise we just
-    // flip the last value, assuming the new token matches what we expect.
-    bool setup = (log_endpoint == 0 && TOK_PID(idx) == SETUP_TOKEN);
-    if (((Data1 >> endpoint) & 1) == ((bdt[idx].info >> 6) & 1)) {
-        if (setup && (buffer[6] == 0)) {
-            set_DATA0(EP0OUT);          // no setup data stage, so set DATA0
+        // copy the data
+        memcpy(buffer, ep_buf, sz);
+        *bytesRead = sz;
+
+        // Figure the DATA0/DATA1 bit for the next packet received on this
+        // endpoint.  The bit normally toggles on each packet, but it's
+        // special for SETUP packets on endpoint 0.  The next OUT packet
+        // after a SETUP packet with no data stage is always DATA0, even
+        // if the SETUP packet was also DATA0.
+        if (((Data1 >> endpoint) & 1) == ((bdt[idx].info >> 6) & 1)) 
+        {
+            if (setup && (buffer[6] == 0))  // if no setup data stage,
+                Data1 &= ~1UL;              // set DATA0
+            else
+                Data1 ^= (1 << endpoint);   // otherwise just toggle the last bit
         }
-        else {
-            toggle_DATA01(endpoint);    // in other cases, toggle the DATA0/DATA1 status on each packet 
-        }
-    }
 
-    // hand off the BDT to start the next read
-    bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK | (((Data1 >> endpoint) & 1) << 6);
-
-    // If this is a SETUP packet, clear the "suspend token busy" hardware flag.
-    // The SIE sets this bit during setup to allow non-interrupted processing.
-    if (setup)
+        // set up the BDT entry to receive the next packet, and hand it to the SIE to fill    
+        bdt[idx].byte_count = epMaxPacket[endpoint];
+        bdt[idx].info = BD_DTS_MASK | BD_OWN_MASK | ((Data1 >> endpoint) << 6);
+    
+        // clear the SUSPEND TOKEN BUSY flag to allow the SIE to continue processing tokens
         USB0->CTL &= ~USB_CTL_TXSUSPENDTOKENBUSY_MASK;
     
-    // operation completed
+        // clear the completion flag
+        epComplete &= ~EP(endpoint);
+    }
+    EXIT_CRITICAL_SECTION
+        
+    // the read is completed
     return EP_COMPLETED;
 }
 
 EP_STATUS USBHAL::endpointWrite(uint8_t endpoint, uint8_t *data, uint32_t size) 
 {
-    // validate the endpoint number
-    if (endpoint >= NUMBER_OF_PHYSICAL_ENDPOINTS)
-        return EP_INVALID;
-
-    // if write on a OUT endpoint -> error
-    if (OUT_EP(endpoint))
+    // validate the endpoint number and direction
+    if (endpoint >= NUMBER_OF_PHYSICAL_ENDPOINTS || !IN_EP(endpoint))
         return EP_INVALID;
 
-    // get the BDT entry for the endpoint
+    // get the BDT index
     int idx = EP_BDT_IDX(PHY_TO_LOG(endpoint), TX, 0);
+    
+    // get the buffer pointer
+    uint8_t *buf = endpoint_buffer[endpoint];
 
-#if 0
-#ifdef DEBUG_PRINTF
-    if (endpoint == EP0IN && !(epReady & EP(endpoint))) printf("!!! EP0 write not ready\r\n");
-#endif
-    // $$$
-    // if the endpoint isn't ready, return BUSY, since we have an outstanding
-    // write that hasn't completed yet
-    if (!(epReady & EP(endpoint)))
-        return EP_BUSY;
-#else
-    // If the endpoint isn't marked as ready, return BUSY, since we have an
-    // outstanding write on the endpoint that hasn't completed yet.  Skip this
-    // test for EP0, since EP0 is handled entirely through interrupt callbacks
-    // and packet exchange is inherently serialized by the protocol.  
-    if (endpoint != EP0IN && !(epReady & EP(endpoint)))
-        return EP_BUSY;
-#endif
+    ENTER_CRITICAL_SECTION
+    {
+        // copy the data to the hardware buffer
+        bdt[idx].byte_count = size;
+        memcpy(buf, data, size);
 
-    // copy the bytes to the endpoint hardware buffer
-    uint8_t *ep_buf = (uint8_t *)bdt[idx].address;
-    bdt[idx].byte_count = size;
-    for (uint32_t n = 0 ; n < size ; n++)
-        ep_buf[n] = data[n];
+        // flip the DATA1 bit before sending    
+        Data1 ^= (1 << endpoint);
 
-    // toggle DATA0/DATA1 on each packet
-    toggle_DATA01(endpoint);
-    
-    // mark the endpoint as not ready and not complete
-    clear_completion(endpoint);
-    clear_ready(endpoint);
+        // hand the BDT to the SIE hardware, and set the current DATA1 bit
+        bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK | ((Data1 >> endpoint) << 6);
+    }
+    EXIT_CRITICAL_SECTION
 
-    // hand the buffer to the SIE
-    bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK | (((Data1 >> endpoint) & 1) << 6);
-
-    // the packet is now pending
+    // the operation is now pending
     return EP_PENDING;
 }
 
 EP_STATUS USBHAL::endpointWriteResult(uint8_t endpoint) 
 {
-    // if the endpoint is ready, and the completion flag is set, we're done
-    uint32_t mask = EP(endpoint);
-    if ((epReady & mask) && (epComplete & mask)) {
-        clear_completion(endpoint);
-        return EP_COMPLETED;
+    EP_STATUS result = EP_PENDING;
+
+    ENTER_CRITICAL_SECTION
+    {
+        if (epComplete & EP(endpoint)) {
+            epComplete &= ~EP(endpoint);
+            result = EP_COMPLETED;
+        }
     }
+    EXIT_CRITICAL_SECTION
     
-    return EP_PENDING;
+    return result;
 }
 
 void USBHAL::stallEndpoint(uint8_t endpoint) 
 {
-#ifdef DEBUG_PRINTF
-    printf("Stall %d\r\n", endpoint);
-#endif
-    int idx = PEP_BDT_IDX(endpoint, EVEN);
-    if ((epReady & EP(endpoint)) && !(bdt[idx].info & BD_OWN_MASK))
-        bdt[idx].info |= BD_STALL_MASK;
-    else
-        USB0->ENDPOINT[PHY_TO_LOG(endpoint)].ENDPT |= USB_ENDPT_EPSTALL_MASK;
+    USB0->ENDPOINT[PHY_TO_LOG(endpoint)].ENDPT |= USB_ENDPT_EPSTALL_MASK;
 }
 
 void USBHAL::unstallEndpoint(uint8_t endpoint) 
 {
-#ifdef DEBUG_PRINTF
-    printf("Unstall %d\r\n", endpoint);
-#endif
-
-    // get the physical endpoint
-    int logep = PHY_TO_LOG(endpoint);
-    
-    // figure the new endpoint control register flags
-    uint8_t f = IN_EP(endpoint) ? USB_ENDPT_EPTXEN_MASK : USB_ENDPT_EPRXEN_MASK;
-    if (logep != 0)
+    printd("unstall endpoint %d %s\r\n", endpoint>>1,endpoint&1?"TX":"RX");
+    ENTER_CRITICAL_SECTION
     {
-        // add the HANDSHAKE flag if it's not isochronous
-        if (!(epInfo[endpoint].flags & ISOCHRONOUS))
-            f |= USB_ENDPT_EPHSHK_MASK;
+        USB0->ENDPOINT[PHY_TO_LOG(endpoint)].ENDPT &= ~USB_ENDPT_EPSTALL_MASK;
+        int idx = PEP_BDT_IDX(endpoint, 0);
+        bdt[idx].info &= ~(BD_OWN_MASK | BD_STALL_MASK | BD_DATA01_MASK);
+        Data1 &= ~(1 << endpoint);
     }
-            
-    // set the new flags
-    USB0->ENDPOINT[logep].ENDPT = f;
-    
-    // clear the STALL bit in the endponit control register
-    USB0->ENDPOINT[logep].ENDPT &= ~USB_ENDPT_EPSTALL_MASK;
-    
-    // clear the stall bit in the BDT, and take ownership
-    int idx = PEP_BDT_IDX(endpoint, EVEN);
-    bdt[idx].info &= ~(BD_OWN_MASK | BD_STALL_MASK);
-    
-    // the endpoint is now NOT COMPLETED
-    clear_completion(endpoint);
-    
-    // Set the data flag to DATA1 for the endpoint.  If it's TX, the next
-    // packet sent needs to be DATA0, and write flips the bit first, so we
-    // want it to be DATA1 now.  If it's RX, we're about to start a read
-    // with DATA0, so the next read will be back to DATA1.
-    set_DATA1(endpoint);
-
-    // check the endpoint type for final settings
-    if (IN_EP(endpoint))
-    {
-        // TX endpoint - mark as ready so that next write operation can proceed,
-        // and set the DATA1 flag so that the next packet will be sent as DATA0
-        // (the write opereation flips the bit before sending)
-        set_ready(endpoint);
-    }
-    else
-    {
-        // RX endpoint - start next read operation with DATA0
-        if (epReady & EP(endpoint))
-        {
-            clear_ready(endpoint);
-            bdt[idx].byte_count = epInfo[endpoint].bufsiz;
-            bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK;
-        }
-    }
+    EXIT_CRITICAL_SECTION
 }
 
 bool USBHAL::getEndpointStallState(uint8_t endpoint) 
 {
-    return (USB0->ENDPOINT[PHY_TO_LOG(endpoint)].ENDPT & USB_ENDPT_EPSTALL_MASK) != 0;
+    uint8_t stall = (USB0->ENDPOINT[PHY_TO_LOG(endpoint)].ENDPT & USB_ENDPT_EPSTALL_MASK);
+    return (stall) ? true : false;
 }
 
-void USBHAL::remoteWakeup(void) {
+void USBHAL::remoteWakeup(void) 
+{
     // [TODO]
 }
 
 
-void USBHAL::_usbisr(void) {
+void USBHAL::_usbisr(void) 
+{
+    inIRQ = true;
     instance->usbisr();
+    inIRQ = false;
 }
 
 
@@ -638,32 +578,22 @@
     uint8_t istat = USB0->ISTAT;
 
     // reset interrupt
-    if (istat & USB_ISTAT_USBRST_MASK) 
-    {
-#ifdef DEBUG_PRINTF
-       // printf("\r\n>>> USB RESET\r\n");
-#endif
-
+    if (istat & USB_ISTAT_USBRST_MASK) {
+        
         // disable all endpt
-        for(i = 0 ; i < 16 ; i++) {
+        for(i = 0 ; i < 16 ; i++)
             USB0->ENDPOINT[i].ENDPT = 0x00;
-        }
 
         // enable control endpoint
         realiseEndpoint(EP0OUT, MAX_PACKET_SIZE_EP0, 0);
         realiseEndpoint(EP0IN, MAX_PACKET_SIZE_EP0, 0);
 
         Data1 = 0x55555555;
-        epComplete = 0;
-        
-        // Reset the SIE even/odd buffer state.  We keep this bit
-        // set throughout the session, which makes the EVEN buffer
-        // the only one that's ever used, effectively disabling the
-        // double-buffering system.
         USB0->CTL |=  USB_CTL_ODDRST_MASK;
 
-        USB0->ERRSTAT =  0xBF;  // clear all error flags
-        USB0->ERREN   =  0x9F; // 0xBF;  // enable error interrupt sources 
+        USB0->ISTAT   =  0xFF;  // clear all interrupt status flags
+        USB0->ERRSTAT =  0xFF;  // clear all error flags
+        USB0->ERREN   =  0xFF;  // enable error interrupt sources
         USB0->ADDR    =  0x00;  // set default address
         
         // notify upper layers of the bus reset
@@ -671,175 +601,115 @@
         
         // we're not suspended
         suspendStateChanged(0);
-
-        // clear all interrupt status flags and return        
-        USB0->ISTAT = 0xFF;
+        
+        // return now - do no more processing on a RESET interrupt
         return;
     }
 
     // resume interrupt
-    if (istat & USB_ISTAT_RESUME_MASK) {
+    if (istat & USB_ISTAT_RESUME_MASK) 
+    {
         suspendStateChanged(0);
         USB0->ISTAT = USB_ISTAT_RESUME_MASK;
-        return;
     }
 
     // SOF interrupt
-    if (istat & USB_ISTAT_SOFTOK_MASK) {
-        // SOF event, read frame number
+    if (istat & USB_ISTAT_SOFTOK_MASK) 
+    {
+        // Read frame number and signal the SOF event to the callback
         SOF(frameNumber());
         USB0->ISTAT = USB_ISTAT_SOFTOK_MASK;
-        return;
     }
 
     // stall interrupt
     if (istat & USB_ISTAT_STALL_MASK)
     {
-#ifdef DEBUG_PRINTF
-        printf("\r\n>>>>STALL INTERRUPT\r\n");
-#endif
-        if (USB0->ENDPOINT[0].ENDPT & USB_ENDPT_EPSTALL_MASK) {
+        // if the control endpoint (EP 0) is stalled, unstall it
+        if (USB0->ENDPOINT[0].ENDPT & USB_ENDPT_EPSTALL_MASK)
+        {
+            unstallEndpoint(EP0OUT);
             unstallEndpoint(EP0IN);
-            unstallEndpoint(EP0OUT);
         }
+        
+        // clear the SUSPEND flag to allow token processing to continue
         USB0->CTL &= ~USB_CTL_TXSUSPENDTOKENBUSY_MASK;
-        USB0->ISTAT = USB_ISTAT_STALL_MASK;
-        return;
+        USB0->ISTAT |= USB_ISTAT_STALL_MASK;
     }
 
-    // TOKEN DONE interrupt
-    if (istat & USB_ISTAT_TOKDNE_MASK)
+    // token interrupt
+    if (istat & USB_ISTAT_TOKDNE_MASK) 
     {
-        uint32_t stat = USB0->STAT;
-        uint32_t num  = (stat >> 4) & 0x0F;
-        uint32_t dir  = (stat >> 3) & 0x01;
-        uint32_t ev_odd = (stat >> 2) & 0x01;
+        uint32_t num  = (USB0->STAT >> 4) & 0x0F;
+        uint32_t dir  = (USB0->STAT >> 3) & 0x01;
+        uint32_t ev_odd = (USB0->STAT >> 2) & 0x01;
         int endpoint = (num << 1) | dir;
-        int idx = EP_BDT_IDX(num, dir, ev_odd);
-        int pid = TOK_PID(idx);
-        int len = bdt[idx].byte_count;
-        
-        if (ev_odd) printf("!!! odd BDT entry???\r\n");//$$$
 
-        // endpoint is ready for next operation
-        epReady |= EP(endpoint);
-        // if (num == 0) epReady |= EP(EP0OUT) | EP(EP0IN);
-        
-        //$$$for (int i = 0 ; (bdt[idx].info & BD_OWN_MASK) && i < 10000000 ; ++i) ;
-        //$$$static int unrel;
-       //$$$ if (bdt[idx].info & BD_OWN_MASK) { printf("\r\nIRQ: BDT wasn't released from SIE to CPU (ep=%d)\r\n", endpoint); } 
-        if (pid == SETUP_TOKEN && len != 8) {
-            pid = OUT_TOKEN;
-          //$$$  printf("IRQ: SETUP packet has wrong size (%d)\r\n", bdt[EP_BDT_IDX(num, dir, ev_odd)].byte_count);//$$$
-        }
-            
         // setup packet
-        if (num == 0 && pid == SETUP_TOKEN)
+        if (num == 0 && dir == RX && TOK_PID(EP_BDT_IDX(num, dir, ev_odd)) == SETUP_TOKEN) 
         {
             Data1 &= ~0x02;
-            //bdt[EP_BDT_IDX(0, TX, EVEN)].info &= ~BD_OWN_MASK;
-            //bdt[EP_BDT_IDX(0, TX, ODD )].info &= ~BD_OWN_MASK;
-
+            bdt[EP_BDT_IDX(0, TX, EVEN)].info &= ~BD_OWN_MASK;
+            bdt[EP_BDT_IDX(0, TX, ODD)].info  &= ~BD_OWN_MASK;
+            
             // EP0 SETUP event (SETUP data received)
             EP0setupCallback();
         } 
-        else if (pid == OUT_TOKEN)
+        else 
         {
             // OUT packet
-            if (num == 0)
-                EP0out();
-            else 
+            if (TOK_PID((EP_BDT_IDX(num, dir, ev_odd))) == OUT_TOKEN) 
             {
-                epComplete |= EP(endpoint);
-                if ((instance->*(epCallback[endpoint - 2]))())
-                    epComplete &= ~EP(endpoint);
-            }
-        }
-        else if (pid == IN_TOKEN)
-        {
-            // IN packet
-            if (num == 0) 
-            {
-                EP0in();
-                if (set_addr == 1) 
-                {
-                    USB0->ADDR = addr & 0x7F;
-                    set_addr = 0;
+                if (num == 0)
+                    EP0out();
+                else {
+                    epComplete |= EP(endpoint);
+                    if ((instance->*(epCallback[endpoint - 2]))()) {
+                        epComplete &= ~EP(endpoint);
+                    }
                 }
             }
-            else 
+
+            // IN packet
+            if (TOK_PID((EP_BDT_IDX(num, dir, ev_odd))) == IN_TOKEN) 
             {
-                epComplete |= EP(endpoint);
-                if ((instance->*(epCallback[endpoint - 2]))())
-                    epComplete &= ~EP(endpoint);
+                if (num == 0) {
+                    EP0in();
+                    if (set_addr == 1) {
+                        USB0->ADDR = addr & 0x7F;
+                        set_addr = 0;
+                    }
+                }
+                else {
+                    epComplete |= EP(endpoint);
+                    if ((instance->*(epCallback[endpoint - 2]))()) {
+                        epComplete &= ~EP(endpoint);
+                    }
+                }
             }
         }
 
+        USB0->CTL &= ~USB_CTL_TXSUSPENDTOKENBUSY_MASK;
         USB0->ISTAT = USB_ISTAT_TOKDNE_MASK;
-        return;
     }
 
     // sleep interrupt
     if (istat & USB_ISTAT_SLEEP_MASK) 
     {
-#ifdef DEBUG_PRINTF
-        //printf("\r\n>>> USB SLEEP INTERRUPT\r\n");
-#endif
         suspendStateChanged(1);
-        USB0->ISTAT = USB_ISTAT_SLEEP_MASK;
-        return;
+        USB0->ISTAT |= USB_ISTAT_SLEEP_MASK;
     }
 
     // error interrupt
     if (istat & USB_ISTAT_ERROR_MASK) 
     {
-        uint32_t errstat = USB0->ERRSTAT;
-#ifdef DEBUG_PRINTF
-        printf("\r\n>>>>ERROR INTERRUPT: ERRSTAT=%x\r\n", errstat);
-#endif
-        if (errstat & 0x20)
-            USB_DMAERR = true;
-
-        // reset the error status
-        USB0->ERRSTAT = 0xBF;
-        
-        // allow the SIE to continue token processing
+        // reset all error status bits, and clear the SUSPEND flag to allow
+        // token processing to continue
+        USB0->ERRSTAT = 0xFF;
         USB0->CTL &= ~USB_CTL_TXSUSPENDTOKENBUSY_MASK;
-
-        // reset the interrupt
-        USB0->ISTAT = USB_ISTAT_ERROR_MASK;
-        return;
+        USB0->ISTAT |= USB_ISTAT_ERROR_MASK;
     }
 }
 
-
-#ifdef DEBUG_PRINTF
-void USBDeviceStatusDump()
-{
-    printf("USBDevice status:\r\n");
-    printf("        0  0  1  1  2  2  3  3  4  4  5  5  6  6  7  7  8  8  9  9 10 10 11 11 12 12 13 13 14 14 15 15\r\n");
-    printf("       RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX RX TX\r\n");
-    printf("Data1  ");
-    for (int i = 0 ; i < 32 ; ++i)
-        printf(" %d ", (Data1 >> i) & 1);
-    printf("\r\n"
-           "Cmplt  ");
-    for (int i = 0 ; i < 32 ; ++i)
-        printf(" %d ", (epComplete >> i) & 1);
-    printf("\r\n"
-           "Ready  ");
-    for (int i = 0 ; i < 32 ; ++i)
-        printf(" %d ", (epReady >> i) & 1);
-    printf("\r\n"
-           "OWN    ");
-    for (int i = 0 ; i < 16 ; ++i)
-        printf(" %d  %d ", (bdt[EP_BDT_IDX(i, RX, 0)].info >> 7) & 1, (bdt[EP_BDT_IDX(i, TX, 0)].info >> 7) & 1);
-    printf("\r\n"
-           "Stall  ");
-    for (int i = 0 ; i < 16 ; ++i)
-        printf("  %s   ", (USB0->ENDPOINT[i].ENDPT & USB_ENDPT_EPSTALL_MASK) ? "S" : ".");
-    printf("\r\n\r\n");
-}
-#endif
+void USBDeviceStatusDump() { }
 
 #endif