@FBL Thanks for the reply. I have managed the hard fault handler issue in my code and now the ux_device_class_cdc_acm_write_with_callback API in non-blocking mode works successfully. But the speed is now reduced to 3 MBPS from 5 MBPS of the blocking mode API.
I have also tried by enabling the internal IP DMA in the configuration. Below attaching the screenshots of ioc configuration for DMA. The GPDMA configuration was already from the example project.
After enabling the DMA in ioc, the write function _ux_dcd_stm32_transfer_request failed to send the data over USB and it is waiting for a semaphore,
/* We should wait for the semaphore to wake us up. */
status = _ux_utility_semaphore_get(&transfer_request -> ux_slave_transfer_request_semaphore,
(ULONG)transfer_request -> ux_slave_transfer_request_timeout);So, My doubt is that, Is there any other configurations need to be done for working of the internal DMA? So this where I stuck in DMA configuration.
Next is in the working project without enabling DMA and using the call-back method, there is an another issue which I suspect a delay which limits the speed of USB. I will explain the issue.
After calling the ux_device_class_cdc_acm_write_with_callback function in usbx_cdc_acm_write_thread_entry, I will wait in the thread to finish the transaction and to execute the call-back function from _ux_device_class_cdc_acm_bulkin_thread. Here is the code in usbx_cdc_acm_write_thread_entry.
while(total_bytes_to_send)
{
if (usb_ready)
{
usb_ready = 0;
if (buf_indx >= APP_TX_DATA_SIZE)
{
buf_indx = 0;
}
if (total_bytes_to_send > APP_TX_DATA_SIZE)
{
bytes_to_send = APP_TX_DATA_SIZE;
}
else
{
bytes_to_send = total_bytes_to_send;
}
if (ux_device_class_cdc_acm_write_with_callback(cdc_acm, (UCHAR *)(&UserTxBufferFS[buf_indx]),
bytes_to_send) != UX_SUCCESS)
{
// Error condition
total_bytes_to_send = 0;
}
}
/* Sleep thread for 10ms */
tx_thread_sleep(MS_TO_TICK(10));
}Here, the usb_ready flag is set from the call-back function after each write. The issue is with the sleep here tx_thread_sleep(MS_TO_TICK(10)); , without this 10ms delay the event send from the application will not be triggering the _ux_device_class_cdc_acm_bulkin_thread function to send the data.
/* Wait until we have a event sent by the application. */
status = _ux_utility_event_flags_get(&cdc_acm -> ux_slave_class_cdc_acm_event_flags_group, UX_DEVICE_CLASS_CDC_ACM_WRITE_EVENT,
UX_OR_CLEAR, &actual_flags, UX_WAIT_FOREVER);
/* Check the completion code. */
if (status == UX_SUCCESS)
{So is this delay is not avoidable? Maybe this causes the throughput issue in USB on call-back method in my case. Please let me know your comments/suggestions. I have been trying for a while to increase the USB speed in U5A5.
@tjaekel Could you please suggest an article or a document to configure the USB DMA. Or your method. And RAM size is almost 2.5 MB, that's why I have used it like a luxury, maybe it could cause an issue later, Thanks for pointing it out.
