TMS320F28379D: USB driver cannot be recognized by computer

Howard Zou

Part Number: TMS320F28379D
Other Parts Discussed in Thread: CONTROLSUITE, C2000WARE

Hi, my customer is using the example code below.

D:\controlSUITE\controlSUITE\device_support\F2837xD\v210\F2837xD_examples_Cpu1\usb_dev_serial

1. He did some modification and program the code to flash instead of ram, and then power down and up the board and found that the USB cannot be recognized by computer. Any idea what would be the reason?

2. He is trying to build a master program on computer to communicate with MCU through USB to upgrade the software in MCU. He wrote the code that the MCU will transmit 168 bytes data through USB to computer every 1ms, but found that there will be data loss every 6ms. He monitor the data length through BusHound.

By monitoring the USB_D+ waveform, the yellow line in the pic below, it's found that the 168 byte data is divided into 3 groups to be transmitted. Is this correct?

The customer is using

USBBufferWrite((tUSBBuffer *)&g_sTxBuffer,(uint8_t *)&USBTxBuf,168);

He wonders that how many bytes can be sent by USBBufferWrite at a time.

over 8 years ago

0 Baskaran Chidambaram over 8 years ago

TI__Genius 17370 points

Hello,
I am writing to let you know that a C2000 team member has been assigned to this post and should be answering shortly.

Regards
Baskaran

0 Sal Pezzino over 8 years ago

TI__Mastermind 32995 points

Please use the windows_drivers available in C2000Ware. These drivers have been signed and updated.

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

Thank you sal.
How about the loss of data, do you have any idea what could be the reason?

How many bytes can be sent by USBBufferWrite at a time?

Regards,
Howard

0 Sal Pezzino over 8 years ago in reply to Howard Zou

TI__Mastermind 32995 points

It is possible you are overwriting the buffer to the USB FIFO. If you delay some of the writing to the Buffer, does that solve the problem?

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

Thanks. Are there any limit of bytes for USBBufferWrite at a time?

By delay, do you think that if I need to send 168 bytes every 1ms, I can send 21 bytes every 1/8 ms? Because I can't tolerate slower transmitting speed.

0 Sal Pezzino over 8 years ago in reply to Howard Zou

TI__Mastermind 32995 points

I do not think this should be a problem. You should be able to fill up the buffer as long as you do not overflow it. It depends on two thing, how large the software buffer is and how large the physical buffer is. There should not be a problem with the physical USB buffer. Just make sure you are not overflowing the software buffer. You can implement this check in software.

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

Thanks for your reply.
By monitoring the USB_D+ waveform, the yellow line in the pic in my post, it's found that the 168 byte data is divided into 3 groups to be transmitted. Is this correct? What may cause the problem?
Howard

0 Sal Pezzino over 8 years ago in reply to Howard Zou

TI__Mastermind 32995 points

This is likely correct. Bulk devices send maximum 64 byte packets.

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

But this is in serial mode, not bulk mode.
Howard

0 Sal Pezzino over 8 years ago in reply to Howard Zou

TI__Mastermind 32995 points

64 bytes per packet is still the maximum.

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

Thanks for your reply.

Do you have any idea why the time between every packet is as long as 10us?(yellow line)

For the green line, the time between every packet is rather small, it's the waveform of USB D+ from another company who is also using F28379.

green line- good USB communication of another company

yellow line- bad USB communication(data loss) of my customer

they are both using F28379.

Howard

0 Sal Pezzino over 8 years ago in reply to Howard Zou

TI__Mastermind 32995 points

I cannot be 100% sure. I have been able to achieve 7-8 kbps using USB on F2837x. The issue may also be with the PC. The frequency of data transfer depends on both the MCU's ability to transmit it, but also the Data In packets sent by the Host PC to request data.

sal

0 Howard Zou over 8 years ago in reply to Sal Pezzino

TI__Genius 12365 points

Thanks. This post can be closed.

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TMS320F28379D: USB driver cannot be recognized by computer