Protocol SPI 3-wire Read0

[Ola]

Hi, I have an AD3 and want to read a 3-wire SPI. There is a fault in the SPI "Read0" when you use the "Command (DQ0) first. The "DQ0" stay's driven High instead of "High ohmic". I have tried without "Command (DQ0)" and just read at "DQ0" and then it is "High ohmic". Could somebody at Digilent fix this error so I can send a "Command (DQ0)" first and then do Read0?

[attila]

Hi @Ola

Set Initial DQ0 to Z

Thank you for the obsrevation.

[Ola]

This solved the problem. Thanks for the quick and good response:)

[Ola]

I have one more question. When doing Custom script, Is there a command that does the "Command (DQ0)+Read0" or "Command (DQ0) + Write" in one command. It is to slow to do this with:

Start();

Write(8, 0x10 ); // Write Reg1 10 :enable DAC

Read0(16, 1);

Stop();

I would like to have one command for this, or set it in a buffer to send many command's. I need to do a quick "chip select" in between each command? The communication with USB latency is to slow.

Regards, Ola

[attila]

Hi @Ola

The Write/CmdWrite only writes to D0, like:
CmdWrite(8, 0x10, 0, 16, [0x0001]); // write 0x0001 to register 0x10
and for Read0
CmdRead0(8, 0x10, 0, 16, 1); // read one 16bit word from register 0x10

The read/write functions activate CS during the transfer with hardware timing.
You can also use the Start/Stop functions for software CS control but this will take more time (like +1 millisecond) and this is also reflected in CS edge to bit transfer timing.

[Ola]

Thanks for the answer, I think I was looking for your "CmdRead0" explanation. This will speed up the transfer:) I will look into the "Sensor" tab a little bit more. I think I could have a huge speed up here.

[Ola]

Where could I find a list (and explanation) over all the different script command's available for AD3?

I have not find this in any documentation...

[attila]

Hi @Ola

See the Help tab