Measurement Computing Analyzer488 User Manual

Page 39

Advertising
background image

Section 2

Getting Started

2.17

Arm

Record

and

Trigger

Example # 3 Counted trigger word

match with Delay

Match Word = LAG10, Match Count =

2, Trigger Delay = 32768,

Post Trigger Count = 32768 and Tri

gger Complete Action is Step

Buffer Location

0

32k

16K

8K

24k

Trigger

Match

Trigger

Match

Trigger

Point

Delay
Finished

Delay

Started

Disarm

Trigge

and

Set Ste

Handsh

For the diagram shown above, the trigger event was defined as follows:
Match Word = LAG10 (Listen Address Group 10), Match Count =
2,Trigger Delay = 32768, Post Count = 32768, and Trigger Complete
Action = Step.

Once the trigger event was defined, recording and triggering were then
enabled. The Analyzer488 began recording bus transactions, comparing
each event with the defined match word. Each time the match word was
found, the Match Count was decremented. When the Match Count was
decremented to zero, the Analyzer488 began counting and recording bus
events until 32768 events were counted. At that time, the trigger event was
marked and recording continued until 32768 events were recorded. At that
time,recording was still enabled and the handshake circuitry was set to step
mode, halting bus transactions until a step command was issued. The
diagram shows that the event marked as the trigger point is stored at
location 0. The last event recorded in this case will be the last event
recorded before recording was disabled by issuing a command or by a
keypress.

Advertising