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10 years, 7 months ago.
Handshake of USB serial
Handshake of USB serial
I use the yellow mbed LPC11U24. Is it not possible that the USBSerial, and to wait USB communication side (Downstream).
I am a convert to the SPI from USB.
The connection to the host PC via USBSerial of 1) mbed In 2) SPI, and connected to a device
If you send at one time a large amount of data (number of KB), it will drop the data is the SPI side is Busy. I do not know how when busy, to the USB side is Busy SPI.
2 Answers
10 years, 7 months ago.
The handshake is done by the usb protokoll. The USB endpoint has to be send a ack every time a packet is send. If you don't read from the USBSerial the PC can't send data. There are also Isochronous transfers without ack but they are used for audio. Are you shure your PC program is handling the status of the serial line ?
10 years, 7 months ago.
Thank you for reply. I think the PC app, and is processing the Busy of serial line. However, COM port seen from the PC this does not seem to be in Busy.
I'll try to investigate a little more. Thank you.