simplest USB communication on C674x

nayil

Hi,

What is the simplest way of transfering some data from PC to C674x? All I need to do is to receive some data from PC and put them on SDRAM. I am trying to avoid DSP/BIOS and PSP because of the size limitation.

I've heard something like virtual serial emulation. Is it something like I can use a USB port as a RS232? How to implement the device side?

Thanks

over 16 years ago

0 Joe G. over 16 years ago

TI__Mastermind 25966 points

I was pleasantly surprised to see the following get working. Might work for you:

http://e2e.ti.com/forums/p/5103/19608.aspx#19608

0 yl over 16 years ago in reply to Joe G.

Expert 1215 points

I am trying on the same thing and having some problems on my C6745 custom board. The first problem is that the usb_isr isn't called when I plug in the usb to usb0.

One difference is that I am using internal PLL clock from 24M xtal, so my USB2PHYCLKMUX = 1.

My tcf file has

bios.HWI.instance("HWI_INT6").interruptSelectNumber = 19;

bios.HWI.instance("HWI_INT6").fxn = prog.extern("usb_isr");

My usb_init and usb_isr are as follows: (or at http://docs.google.com/View?id=ddskp47r_35gwz3qhhs)

0 yl over 16 years ago in reply to yl

Expert 1215 points

More investigation seemed to suggest the HWI isn't triggered at all. So am I doing this correctly?

bios.HWI.instance("HWI_INT6").interruptSelectNumber = 19;
bios.HWI.instance("HWI_INT6").fxn = prog.extern("usb_isr");

Is there anything else needed?

0 yl over 16 years ago in reply to yl

Expert 1215 points

I can see USB Interrupt Source Register (INTSRCR) changed to 0x000D0001 after I plug or unplug.

Also the EVTFLAG0 turned into 0x00080000 after CSL_FINS(usbRegs->POWER,USB_OTG_POWER_SOFTCONN,1); and stayed at 0x00080000 forever until a system reset.

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simplest USB communication on C674x