• Asking for help

  • Updating `log2_width` setting for simultaneous use of multiple DACs

We would like to use the log2_width setting in order to set many DAC channels at once and would like some clarification on the configuration. Reading the documentation, it looks like we just need to update the parameter in device_db and in the gateware; as this is our first time updating the gateware we're not sure of that exact procedure to accomplish that. The post here implies there was perhaps a different firmware used and we'd like some guidance on any changes we need to make. Additionally, this setting is one that we would like to be able to change periodically for different experiments and want to know if there are any issues with that approach.

Contact your system provider or m-labs/quartiq to have a bitstream built for you.

a month later

@rjo we got the bitstream built and successfully flashed the device but are still unable to use set_group(). We tried following the code from this post exactly, but did not see our DAC channels update with the expected voltages. We have confirmed that we are able to communicate with the DAC card by using set_leds(), and we know the DAC channels themselves are not destroyed because, when we roll back to the previous firmware (log2_width = 0), we are able to set the DAC channels in a loop using set_dac(). With the new firmware (log2_width = 5) we do not get any results. We're not sure whether this or not this is still a firmware issue. Any advice as to how to proceed?

12 days later