Simulink sample time with external sample clock?

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Brian Tremaine
Brian Tremaine on 17 Jul 2019
Commented: Brian Tremaine on 20 Jul 2019
Hi,
I want to run a S&H block with an external sample pulse. I am simulating a mixed signal digital PLL for a motor control. The phase detector is using boolean logic elements and is run from a 5Mhz pulse generator. The phase detector generates a phase count and a sample pulse about every 360Hz. I need this to drive a digital filter but am unclear how to use my boolean 360Hz sample pulse to act as the sample time for my z-domain digital filter.
Thanks ~
Matlab_question.png

Accepted Answer

Jonas
Jonas on 18 Jul 2019
I would suggest to put the digital filter in a triggered subsystem and use the 360 Hz signal as trigger.
  1 Comment
Brian Tremaine
Brian Tremaine on 20 Jul 2019
Thank-you Jonas,
I was using a ZOH with inherited sampling from a D-latch and this was feeding a discrete filter. I was skeptical of this approach since some signals didn't seem correct. I think the triggered sub-system is really what is needed and is closer to my real FPGA code used in the hardware setup.
Brian

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