HI

When at91sam series is in tx master mode, at91sam series can setup data length of 8-16bit by software

QUESTION :HOW CAN SLAVE ACKNOWLEGE DATA BIT LENGTH ?

Both the master and the slave must be set to send/receive the same number of bits during the transmission. This needs to be done prior to the transmission and is presumably be done during your spi setup routines for both the master and the slave.

You could perhaps set up a negotiation between master/slave in which a default setup (say 8bits) is used to tell each chip what the new settings would be, then each would change their settings and hopefully talk again successfully. But that is something that would need to be written in software by you.

Hope this helped.


Chris Lathan

thanks for reply Chris Lathan

I found spi length select bit
That is the CSR register in the BITS select field.

bye!