Logic Shrimp 101 introduction

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Contents

Hardware overview

Logic-diagram-490.jpg

Logicshrimpv1block490px.png

Hardware setup

Logic-shrimp-inuse.jpg

  1. Connect a signal source to inputs 1-4.
  2. It is usually best to ground unused pins.
  3. Connect the Logic Shrimp ground pin to the ground of the device under test.
Input header
Pin FunctionNote
1 Channel 1 input
2 Channel 2 input
3 Channel 3 input
4 Channel 4 input
5 GroundConnect to target ground

Connection settings

Ls-demo-1.png

The Logic Shrimp requires version 0.9.4 RC1 or later of Jawi's logic analyzer client

  • Select the (virtual) serial port number
  • Select the maximum port speed
  • Select the "SHRIMP" device type

Capture setup

Ls-demo-2.png

Here is an example of the configuration settings in the latest client.

  • Up to 256K samples
  • Only one group with four channels is available

Trigger setup

Ls-demo-3.png

The Logic Shrimp configurable edge detection triggers on all pins.

  • Mask enables the trigger for that pin
  • Tick value to trigger on the rising edge, leave clear for falling edge
  • Configure the ratio of samples to return from before and after the trigger
The trigger is currently a very simple OR trigger
Any match on any configured pin will trigger the capture

Start capture

Ls-demo-4.png

Press capture and the ACT LED will light. Wait for the trigger to happen and the capture to complete.

After the capture the ACT LED turns off and the samples are dumped to the client. 256K samples can take a long time to download, even over a high-speed USB serial port.