added cdc example

firmware/applications/cdc.c

@@ -0,0 +1,63 @@
+#include <stdint.h>
+#include "core/usbcdc/usb.h"
+#include "core/usbcdc/usbcore.h"
+#include "core/usbcdc/usbhw.h"
+#include "core/usbcdc/cdcuser.h"
+#include "core/usbcdc/cdc_buf.h"
+
+volatile unsigned int lastTick;
+int puts(const char * str)
+{
+  // There must be at least 1ms between USB frames (of up to 64 bytes)
+  // This buffers all data and writes it out from the buffer one frame
+  // and one millisecond at a time
+    if (USB_Configuration) 
+    {
+      while(*str)
+        cdcBufferWrite(*str++);
+      // Check if we can flush the buffer now or if we need to wait
+      unsigned int currentTick = systickGetTicks();
+      if (currentTick != lastTick)
+      {
+        uint8_t frame[64];
+        uint32_t bytesRead = 0;
+        while (cdcBufferDataPending())
+        {
+          // Read up to 64 bytes as long as possible
+          bytesRead = cdcBufferReadLen(frame, 64);
+          USB_WriteEP (CDC_DEP_IN, frame, bytesRead);
+          systickDelay(1);
+        }
+        lastTick = currentTick;
+      }
+    }
+  return 0;
+}
+
+void main_cdc(void)
+{
+    //lastTick = systickGetTicks();   // Used to control output/printf timing
+    CDC_Init();                     // Initialise VCOM
+    USB_Init();                     // USB Initialization
+    USB_Connect(TRUE);              // USB Connect
+    // Wait until USB is configured or timeout occurs
+    uint32_t usbTimeout = 0; 
+    while ( usbTimeout < CFG_USBCDC_INITTIMEOUT / 10 )
+    {
+      if (USB_Configuration) break;
+      delayms(10);             // Wait 10ms
+      usbTimeout++;
+    }
+    uint8_t buf[2] = {0,0};
+    int l;
+    while(1){
+        CDC_OutBufAvailChar(&l);
+        if( l ){
+            l = 1;
+            CDC_RdOutBuf (buf, &l);
+            puts(buf);
+        }
+        //puts("hello world\r\n");
+        //delayms(1);
+    }
+}