AT91SAM7X256 and SPI support

nobody wrote on Thursday, March 02, 2006:

Is there any support for SPI interface with AT91SAM7X256.  I would like to use interface SPI0 to communicate with a device.

Regards

Christian

nobody wrote on Thursday, March 02, 2006:

Not really the answer, but if you look at the WIZNet demo (LPC not SAM) you will see an I2C driver.  You could at least copy the structure if nothing else.

nobody wrote on Friday, March 03, 2006:

Hum, i really need to have spi interface for rtos.  If a team works on this project, I would like to participate to implement it.

Regards

Christian

nobody wrote on Friday, March 03, 2006:

have you tried using the SPI PDC? I know this isn’t portable but for the SAM7X it is quite interesting. You just config the spi interface and the set the tx_buff & rx_buff address and how many bytes to exchange then voila… you get your data in the rx_buff

jra01 wrote on Tuesday, March 07, 2006:

I tried the PDC for SPI, and I am not so enthusiastic. With bitrates at e g 10 MHz you spend as much time filling the PDC buffer with 32 bit data (for each transfer you need to buffer 32 bit, even if the transfer is only 8 bit) as you would do waitning for the SPI to get ready for the next byte, and for many devices you need the more direct connection between data sent and data received that you can get if you do the transmition under more direct transmission control.

henkvisser wrote on Tuesday, March 07, 2006:

How are you sending out data now?  Just checking for  TDRE and placing data into TDR?

Thanks.

nobody wrote on Wednesday, March 08, 2006:

Thanks,

It works with TDR and RDR.  I wrote the source code and it’s not really complicated. 

Regards

Christian