How to use the 4 channel output

[interwiser]

Hello everyone，I bought PMODDA1, but I don't know how to set PMODDA1 to make two DAC work at the same time in SDK and output 4 channels, and demo on GitHub can only output two channels，I would be very grateful.

[jpeyron]

Hi @interwiser,

When we made the Pmod DA1 IP Core we use just the one DAC due to the difficulty it would take to alter the SPI communication for the non-conventional SPI communication on the Pmod DA1. I talked to our content team about altering the IP Core to work with both DAC's. They responded that it might be possible to configure the wrapped qspi ip as a dual spi controller and use gpio mode on the pmod bridge to set up the tristates. This is not a trivial task. They would not even be able to consider altering the Pmod DA1 IP Core for several months due to time sensitive projects for new products. So at this time I would recommend using the ADD a module function in the Vivado block design along with the VHDL code taken from the Nexys 3 VHDL Example - ISE 13.4 on the resource center here. This forum thread discusses how one customer used the add a module function and should be a good reference for your project.

thank you,

Jon