The GoLogic does not trigger. The toolbar’s button must be used to end the sampling and download the trace data. No pre-store is used and the trigger marker is placed on the first sample in the data.

The never TriggerForm makes the GoLogic function like a data recorder. It is most useful when capturing very slow signals which you can control when the values change.

The simple TriggerForm can be edited in the Triggering tab…
 

In the following example, the GoLogic triggers if the trailing edge of a high-pulse occurs earlier than 160 ns or later than 400 ns measured from the initial edge. Trailing edges that occur within a 240 ns window do not cause the GoLogic to trigger. Anything outside that window is considered an error. The form resets if the trailing edge is 160 ns beyond the upper limit...
 

Levels should not be skipped and unused levels should be deleted. The software automatically maps the abstract TriggerForms to the available triggering resources in the hardware. The software automatically skips levels to deliver the requested trigger resources.

Event lines have two elements: the channel group name and the trigger value. The "anything" event is a placeholder which triggers if any input occurs on any GoLogic channel. The "anything" event is seldom used for this reason. Otherwise, select a channel group name and the trigger value for the event. For example, choosing the "RD*" group (which contains only one channel)...

The "rising edge" and "falling edge" triggers are only available when a single-channel group is selected and timing analysis is active.

Selecting a group with 2 or more channels allows you to enter a trigger value...
 

When a group contains 2 or more channels, the qualifier allows triggering when the channels fall inside or outside a range of values...
 

The "between" and "outside" range events are only available when state analysis is active.
 

Level edit-actions are found under the "Level" buttons...

Select the I2C trigger type from the list...
 

• "Address" triggers on a single I2C address
• "Address & data" triggers on a single I2C data value at an address.
• "Address series" triggers on a series of I2C address values.
• "Data series" triggers on a series of I2C data values at an address.

The SPI bus parameters must be defined correctly in the Sampling tab. These setup values are used by the SPI TriggerForm, the SPI interpreter in the WaveForm window, the SPI PlugIn, and the SPI search and filter tools. If the SPI setup is incorrect in the Sampling tab, none of the other tools will work correctly. See Chapter 2 - Setup step one: sampling for details on the SPI sampling setup.

Enter the SPI bus value you want to detect in the SPI form. The following example triggers when the "34" data value appears on the SPI bus MISO signal...
 

The GoLogic hardware is limited to 8 trigger-states. This limitation determines the number of serial bits that can be detected. If the SPI Packets are separated… option is used, the GoLogic uses the first trigger-state to detect the space between packets. This means 7 states remain to detect the data bits.

Data bits which do not change use 1 trigger-state. Therefore, only 1 trigger-state is required to trigger on the SPI value 0xFFFFFFFF which uses 32-bits. In contrast, the 8-bit values 0xAA and 0x55 requires 8 unique trigger-states.

If an SPI trigger value is entered that exceeds the GoLogic trigger capabilities, all serial bits beyond the last trigger-state are ignored. The SPI TriggerForm displays a warning message when this happens.

The "?" character is a placeholder that warns you the trigger should be viewed in binary rather than hexadecimal. Each hex character represents 4 channels. If you edit a trigger value in binary, set three channels to 0 or 1, leave the fourth channel "x", then switch to the hex display, the "?" character will be displayed for the ambiguous hex character...
 

The "?" character cannot be entered from the keyboard. The GoLogic software automatically displays this value when needed.

• Verify the channel connections are secure.
• Connect at least one ground channel to the test circuit’s ground.
• Verify the threshold levels are valid for the input signals.
• Use the activity indicators to verify the input signals are changing.
• The "Trigger" action must appear on at least one level if the Custom TriggerForm is used.
• Be careful when using the "not equals" qualifier. For example, the "anything" trigger value and values which use only the "x" character matches all samples. A "not equals" qualifier used with an "anything" event matches no samples.
• The GoLogic never triggers if a level jumps to itself and never reaches a trigger action...
  
  Another If/Else line on the level must use the trigger action or jump to another level which uses the trigger action...
  
  The Level flow-diagram to the right of the custom form is helpful to identify unreachable levels or levels which reach the trigger action...
  
• Verify the trigger event does not occur while the GoLogic is pre-filling. See the Pre-fill section below for details.

The above example stores incoming data where the "pod A" channels match "1234. Only If/Else blocks which use the "Store sample" option are stored to the GoLogic trace memory. Samples which do not match a stored If/Else blocks will not appear in the captured trace data.

To store no samples to trace memory while on a level, set all If/Else blocks to the "Don't store sample" option...

Alternatively, the "Anything" placeholder can be used in the If/Else block to disable all storage while on a level...

• After the GoLogic detects the trigger and is still running, the "All samples" option stores all incoming channel data to memory. This is the default setting for the post-trigger storage option.
• Choosing the "Only samples matching..." option allows you to specific which incoming channel data is stored to memory after the trigger is detected. In the above example, only incoming data where the "pod A" channels match "1234" are stored in the captured trace data.

When using the "Only samples matching..." option, the stored values are configured just like the TriggerForms, and just like the level storage options described above.

The pre-fill period ensures that the requested trigger sample position is correct. When the button is pressed, the GoLogic initially disables its trigger circuits and cannot trigger. Trace data is captured until enough samples are stored to memory to satisfy the pre-store condition. For example, if the memory depth is 8K samples and a 50% pre-store is requested, then the GoLogic stores 4K samples to memory before enabling the trigger circuits. This prevents the GoLogic from triggering when only 1K samples have been stored to memory. If this occurs, the trigger sample would be positioned about 15% of the trace size instead of the requested 50%.

However, some tests demand that the trigger circuits be immediately activated even if this means the trigger sample is placed on the wrong sample. This usually is required when the trace data is stored very slowly and waiting for the pre-fill period to expire would take hours or even days. Transitional timing and selective storage are the two examples where the trace data might be captured very slowly.

Therefore, the GoLogic provides the "No pre-fill" option on the Quick Setup toolbar...
 

The No pre-fill option is hidden when the sampling modes does not allow the pre-fill to be disabled. For example, normal timing always uses a pre-fill period.