AnsweredAssumed Answered

STM32F2/4 USB HOST MSC transferrate improvements

Question asked by krueger.thomas on Jul 28, 2014
Latest reply on Jul 28, 2014 by Clive One
Good morning,

i am currently experimenting with the USB HOST MSC example as of Lib V2.1.0 .

I do have a custom hardware and managed to get the usb host msc example working.
At first i had attachment problems , io-problems etc.....which was caused by the USB_OTG_BSP_uDelay (uint32_t usec)  function being inaccurate in timing.

After tuning it to correct timing everything runs perfect.

Connecting a USB stick to the board i am getting the following speeds:
Read: ~780k bytes per second
Write: ~436k bytes per second.

I do not have deep insight of the usb stack as such and am wondering if that speed can get better.

in usb_conf.h there are some buffersizes defined:

 #define RX_FIFO_FS_SIZE                          128
 #define TX0_FIFO_FS_SIZE                          64
 #define TX1_FIFO_FS_SIZE                         128
 #define TX2_FIFO_FS_SIZE                          0
 #define TX3_FIFO_FS_SIZE                          0
 #define TXH_NP_FS_FIFOSIZ                         96
 #define TXH_P_FS_FIFOSIZ                          96
 
Can these influence the transfer speed?

Outcomes