Problems with USB VCOM on Cortex-M0+ and USB RL

Hi Tsuneo, I do not have an additional USB hub near me at the time, however, the device is directly connected to USB ports on my machine. I am doing development inside of a VMWare VM, but I tried to open the port in the VM and on the native OS with the same result. Is it possible that multiple USB requests are getting placed into an incoming buffer together and only the first one is processed? The only thing I am doing in the code is polling the USB library:

while (1) {                          // Loop forever
                usbd_vcom_serial2usb();            // write to USB VCOM Port
                usbd_vcom_chkserstate();           // check status
                usbd_vcom_usb2serial();            // write to Serial Port
        }

Not sure what can be causing timing issues there. I don't have access to a hardware USB sniffer either so I was thinking of adding some way to log USB requests to the USB0 ISR to compare sequence numbers of requests (wValueH,wValueL) and storing them in RAM then checking with a debugger to see if I can match them up with what I see in the software USB capture. Does this this sound like an OK idea or should I try a different approach? Thanks.

Hi Tsuneo, I do not have an additional USB hub near me at the time, however, the device is directly connected to USB ports on my machine. I am doing development inside of a VMWare VM, but I tried to open the port in the VM and on the native OS with the same result. Is it possible that multiple USB requests are getting placed into an incoming buffer together and only the first one is processed? The only thing I am doing in the code is polling the USB library:

while (1) {                          // Loop forever
                usbd_vcom_serial2usb();            // write to USB VCOM Port
                usbd_vcom_chkserstate();           // check status
                usbd_vcom_usb2serial();            // write to Serial Port
        }

Not sure what can be causing timing issues there. I don't have access to a hardware USB sniffer either so I was thinking of adding some way to log USB requests to the USB0 ISR to compare sequence numbers of requests (wValueH,wValueL) and storing them in RAM then checking with a debugger to see if I can match them up with what I see in the software USB capture. Does this this sound like an OK idea or should I try a different approach? Thanks.

Hi,
same problem on Freescale’s Board TWR-K60N512. There is no example how to use CDC. So I tried to convert one of other examples (HID - which worked), into CDC.
Basically I removed usbd_user_hid.c , KBD.c files from project.
Copied usbd_user_cdc.c and usb_config.c from c:\Keil\ARM\Boards\Keil\MCB2300\RL\USB\Device\CDC\
to project folder and added those 2 files.
After that I modified USBD_Demo.c and usbd_user_cdc.c.
On Windows 7 Professional 64 bit, I used :
mcb2300-vcom.inf, mcb2300-vcom_x86.cat, mcb2300-vcom_amd64.cat files from placed in c:\Keil\ARM\Boards\Keil\MCB2300\RL\USB\Device\CDC\ to install drivers.
(Or its modifications, basically all text in mcb2300-vcom.inf and usb_config.c were set to “Keil”,and PID, VID changed to corresponding values in usb_config.c).
Everything is compiling, and running. But when I am trying open virtual serial port on my Windows application Putty, usbd_cdc_ser_initport(U32 baudrate, U32 databits, U32 parity, U32 stopbits) is called – with proper parameter values (set in Putty). After that Putty
(same with other similar applications), disappears or is locked. So it does not work at all.
I have installed USBlyzer and all communication looks very similar.

CODE:
*USB_Demo.c

#include <RTL.h>
#include <rl_usb.h>
#include "LED.h"
OS_TID task_id_write;
U64 write_stack [1200/8];
__task void writeTask (void);

__task void init (void) {
  os_tsk_prio_self(1);
  usbd_init();
  usbd_connect(__TRUE);
  os_tsk_prio_self(1);
  task_id_write = os_tsk_create_user (writeTask, 1, &write_stack, sizeof (write_stack));
  while (!usbd_configured()){};
   LED_Val(0x0);
  while (1) {
    usbd_vcom_serial2usb();
    usbd_vcom_chkserstate();
    usbd_vcom_usb2serial();
    os_tsk_pass ();
  }
}

/* buffer type                                                                */
typedef struct __SER_BUF_T {
  unsigned int wrIdx;
  unsigned int rdIdx;
  unsigned char data[128];
} SER_BUF_T;

extern unsigned long         ser_txRestart;    /* NZ if TX restart is required       */
extern unsigned short        ser_lineState;    /* ((msr << 8) | (lsr))               */
extern volatile SER_BUF_T    ser_out;          /* Serial data buffers                */
extern volatile SER_BUF_T    ser_in;

#define SER_BUF_SIZE (128)              /* serial buffer in bytes (power 2)   */
#define SER_BUF_MASK (SER_BUF_SIZE-1ul) /* buffer size mask                   */

/* Buffer read / write macros                                                 */
#define SER_BUF_RESET(serBuf)      (serBuf.rdIdx = serBuf.wrIdx = 0)
#define SER_BUF_WR(serBuf, dataIn) (serBuf.data[SER_BUF_MASK & serBuf.wrIdx++] = (dataIn))
#define SER_BUF_RD(serBuf, dataOut) serBuf.rdIdx++; dataOut = serBuf.data[SER_BUF_MASK & (serBuf.rdIdx-1)];
#define SER_BUF_EMPTY(serBuf)      (serBuf.rdIdx == serBuf.wrIdx)
#define SER_BUF_FULL(serBuf)       ((SER_BUF_MASK & serBuf.rdIdx) == (SER_BUF_MASK & (serBuf.wrIdx+1)))
#define SER_BUF_COUNT(serBuf)      (SER_BUF_MASK & (serBuf.wrIdx - serBuf.rdIdx))

__task void writeTask (void)
{
        SER_BUF_RESET(ser_in);
        while(1)
        {
  SER_BUF_WR(ser_in, 'a');
  os_tsk_pass ();

        }
}

int main (void) {
  LED_Init();
  LED_Val(0xFF);
  os_sys_init(init);                    /* Init RTX and start 'init'          */
}

By the way I can see in USBlyzer characters ('a') which I want to sent to PC Host, just after I connect the device to USB.

Hi John,
As you, I tried to convert a HID example into CDC with same problems that you run through.
Did you find the solution?
Thanks,

Hi Ezequiel Brizzio,

There is new version of RL library, but I did not manage to make it work (I tried once to port example). So I downloaded Freescale's USB stack, and using that solution.

Regards,
John