Jump to content
  • 0

Can I make delays of microsecond with AD2 or DD?


DYLee

Question

 Hello,

 I'm trying the Waveforms program to implement my SPI application which will be used to control RHS2116 device. The requirements are 20~25MHz SPI clock, 32-bit length per word, modifiable microsecond resolution delays between words.

 Previously, I tried NI's USB-8452 and found they natively support 8-bit length SPI. It resulted in unintended delays during the transmission.

 I've heard that the AD2 or DD supports 32-bit length SPI, but it seems like the Waveforms program does not support the delay function with microsecond resolution.

 I tried something like wait(1e-6) but it was not able to validate whether it works as I intended with the simulated device.

 Is it able to control the delays between SPI transmissions (between SPI.Stop() and the next SPI.Start()) with a microsecond scale?

Link to comment
Share on other sites

2 answers to this question

Recommended Posts

  • 0

Hi @DYLee

In the newer software version the timings are adjustable in clock units. Currently with up to 8clks delay but we can change this.
For the timing to work consistently, the transfer length should be up to half of the device buffer, otherwise the transfer is split in separate chunks and CS controlled by sw.
Like with 16k "Patterns" device buffer, for 32 bit words at 20MHz and 1 us delay (20clks) it can fit 157 words, 16384/2/(32+20); with 5 us delay 62 words, 16384/2/(32+100)

image.png

image.png

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...