Sign in
Search lpc2000
Subscribe to lpc2000
lpc2000 by Keywords
2106 | ADC | ARM7 | Atmel | Bootloader | CAN | CrossStudio | CrossWorks | DDS | ECos | Ethernet | ETM | FIFO | FLASH | FPGA | GCC | GDB | GNU | GNUARM | GPIO | I2C | IAP | IAR | JTAG | Kickstart | LCD | Linux | LPC | LPC-E2294 | LPC2000 | LPC2100 | LPC2104 | Lpc2106 | Lpc210x | LPC2114 | LPC2119 | LPC2124 | LPC2129 | Lpc2138 | LPC213x | LPC21xx | LPC2210 | LPC2212 | LPC2214 | LPC2292 | LPC2294 | LPC2xxx | LPC3128 | MCB2100 | Olimex | Philips | PWM | Rowley | RTC | RTOS | SPI | SSP | UART | UART0 | UART1 | ULINK | USB | Watchdog | Wiggler
Ads
Discussion Groups
Discussion Groups | LPC2000 | LPC2148 USB DMA
Discussion group dedicated to the Philips LPC2000 family of ARM MCUs
LPC2148 USB DMA - vickermann - May 7 12:10:56 2007
Hello to all,
I still have problems to establish a usb connection in bulk mode via
DMA. I'm able to send one packet of data via DMA but that's it. The
second one fails.
Maybe somebody can answer me some specific questions. That would be great.
1. In my sample code the IN token for EP2 is received via interrupt;
the answer shall be send via DMA. After sending this data back I get
an End of Transfer interrupt. I'm ignoring this interrupt because I
wanna send the next data back after the next IN Token and my datasize
is smaller or equal to the package size. Is this OK ?
2. Why do I get a New DD Request interrupt allthough I reinit my DD
everytime before I send data ?
3. What is the meaning of the possibility to define more than one DD
for one Endpoint ? Is it necessary to have 2 DDs for doublebuffering ?
But what would it be good for to have 4 DDs for example ?
4. Is the End of transfer interrupt necessary for having a buffer to
send which is greater than the package size and than be able to send
the next package in the End of transfer interrupt ?
Please help me with these questions
Thank you all in advance
Wolfgang
(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )
I still have problems to establish a usb connection in bulk mode via
DMA. I'm able to send one packet of data via DMA but that's it. The
second one fails.
Maybe somebody can answer me some specific questions. That would be great.
1. In my sample code the IN token for EP2 is received via interrupt;
the answer shall be send via DMA. After sending this data back I get
an End of Transfer interrupt. I'm ignoring this interrupt because I
wanna send the next data back after the next IN Token and my datasize
is smaller or equal to the package size. Is this OK ?
2. Why do I get a New DD Request interrupt allthough I reinit my DD
everytime before I send data ?
3. What is the meaning of the possibility to define more than one DD
for one Endpoint ? Is it necessary to have 2 DDs for doublebuffering ?
But what would it be good for to have 4 DDs for example ?
4. Is the End of transfer interrupt necessary for having a buffer to
send which is greater than the package size and than be able to send
the next package in the End of transfer interrupt ?
Please help me with these questions
Thank you all in advance
Wolfgang
(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )
Re: LPC2148 USB DMA - Joel Winarske - May 7 12:44:38 2007
> I still have problems to establish a usb connection in bulk mode via
> DMA. I'm able to send one packet of data via DMA but that's it. The
> second one fails.
Have you looked at the TNKernel USB Bulk firmware code?
http://www.tnkernel.com/usb_bulk.html
It uses bulk mode, DMA, and works.
Joel
(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )
Re: LPC2148 USB DMA - vickermann - May 9 3:46:02 2007
--- In l...@yahoogroups.com, Joel Winarske wrote:
> > I still have problems to establish a usb connection in bulk mode via
> > DMA. I'm able to send one packet of data via DMA but that's it. The
> > second one fails.
>
> Have you looked at the TNKernel USB Bulk firmware code?
>
> http://www.tnkernel.com/usb_bulk.html
>
> It uses bulk mode, DMA, and works.
> Joel
>
Thank you very much, Joel.
I still don't understand how it works therefore these sources are
quite complicated but however this is a point to start at.
Regards
Wolfgang
(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )
> > I still have problems to establish a usb connection in bulk mode via
> > DMA. I'm able to send one packet of data via DMA but that's it. The
> > second one fails.
>
> Have you looked at the TNKernel USB Bulk firmware code?
>
> http://www.tnkernel.com/usb_bulk.html
>
> It uses bulk mode, DMA, and works.
> Joel
>
Thank you very much, Joel.
I still don't understand how it works therefore these sources are
quite complicated but however this is a point to start at.
Regards
Wolfgang
(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )